ADS54J20IRMPT [TI]

双通道、12 位、1.0GSPS 模数转换器 (ADC) | RMP | 72 | -40 to 85;
ADS54J20IRMPT
型号: ADS54J20IRMPT
厂家: TEXAS INSTRUMENTS    TEXAS INSTRUMENTS
描述:

双通道、12 位、1.0GSPS 模数转换器 (ADC) | RMP | 72 | -40 to 85

转换器 模数转换器
文件: 总86页 (文件大小:3247K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
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ADS54J20  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
ADS54J20 双通道 12 位、1.0GSPS 模数转换器  
1 特性  
3 说明  
1
12 位分辨率、双通道、1GSPS 模数转换器 (ADC)  
ADS54J20 是一款低功耗、高带宽、12 位、1.0GSPS  
双通道模数转换器 (ADC)。该器件经设计具有高  
SNR,可提供 -157dBFS/Hz 的噪底,从而 协助应用  
在宽瞬时带宽内 实现最高动态范围。该器件支持  
JESD204B 串行接口,数据传输速率高达 10Gbps,每  
ADC 可支持 2 4 条通道。经缓冲的模拟输入可  
在较宽频率范围内提供统一输入阻抗并最大程度地降低  
采样和保持毛刺脉冲能量。可选择将每条 ADC 通道与  
宽带数字下变频器 (DDC) 模块相连。ADS54J20 以超  
低功耗在宽输入频率范围内提供出色的无杂散动态范围  
(SFDR)。  
噪底:–157dBFS/Hz  
频谱性能(–1dBFS 时的 fIN = 170MHz):  
SNR67.8dBFS  
NSD–155dBFS/Hz  
无杂散动态范围 (SFDR)86dBc(包括交错音  
调)  
SFDR89dBc(不包括 HD2HD3 和交错音  
调)  
频谱性能(–1dBFS 时的 fIN = 350MHz):  
SNR65.6dBFS  
NSD–152.6dBFS/Hz  
SFDR75dBc  
JESD204B 接口减少了接口线路数,从而实现高系统  
集成度。内部锁相环 (PLL) 会将 ADC 采样时钟加倍,  
以获得对各通道的 12 位数据进行串行化所使用的位时  
钟。  
SFDR85dBc(不包括 HD2HD3 和交错音  
调)  
通道隔离:fIN = 170MHz 时为 100dBc  
输入满量程:1.9 VPP  
器件信息  
输入带宽 (3dB)1.2GHz  
片上抖动  
器件编号  
ADS54J20  
封装  
封装尺寸(标称值)  
VQFNP (72)  
10.00mm x 10.00mm  
集成宽带数字下变频器 (DDC) 模块  
支持 JESD204B 子类 1 接口:  
(1) 要了解所有可用封装,请参见数据表末尾的可订购产品附录。  
10.0Gbps 时每个 ADC 2 条通道  
5.0Gbps 时每个 ADC 4 条通道  
支持多芯片同步  
170MHz 输入信号的快速傅立叶变换 (FFT)  
0
功耗:1GSPS 时为 1.35W/通道  
{bw = 67.8 dꢀC{  
{C5w = 86 dꢀc  
bon I52,I53 {pur = 89 dꢀc  
-20  
封装:72 引脚超薄型四方扁平无引线 (10mm ×  
10mm)  
-40  
2 应用  
-60  
-80  
雷达和天线阵列  
无线宽带  
电缆 CMTSDOCSIS 3.1 接收器  
通信测试设备  
-100  
-120  
微波接收器  
0
100  
200  
300  
400  
500  
软件定义无线电 (SDR)  
数字转换器  
Input Frequency (MHz)  
5000  
医疗成像和诊断功能  
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,  
intellectual property matters and other important disclaimers. PRODUCTION DATA.  
English Data Sheet: SBAS766  
 
 
 
ADS54J20  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
www.ti.com.cn  
目录  
8.3 Feature Description................................................. 25  
8.4 Device Functional Modes........................................ 33  
8.5 Register Maps......................................................... 44  
Application and Implementation ........................ 68  
9.1 Application Information............................................ 68  
9.2 Typical Application .................................................. 73  
1
2
3
4
5
6
7
特性.......................................................................... 1  
应用.......................................................................... 1  
说明.......................................................................... 1  
修订历史记录 ........................................................... 2  
Device Comparison Table..................................... 3  
Pin Configuration and Functions......................... 3  
Specifications......................................................... 5  
7.1 Absolute Maximum Ratings ...................................... 5  
7.2 ESD Ratings.............................................................. 5  
7.3 Recommended Operating Conditions....................... 6  
7.4 Thermal Information.................................................. 6  
7.5 Electrical Characteristics........................................... 7  
7.6 AC Characteristics .................................................... 8  
7.7 Digital Characteristics ............................................. 11  
7.8 Timing Characteristics............................................. 12  
7.9 Typical Characteristics............................................ 14  
7.10 Typical Characteristics: Contour ........................... 23  
Detailed Description ............................................ 24  
8.1 Overview ................................................................. 24  
8.2 Functional Block Diagram ....................................... 24  
9
10 Power Supply Recommendations ..................... 75  
10.1 Power Sequencing and Initialization..................... 76  
11 Layout................................................................... 77  
11.1 Layout Guidelines ................................................. 77  
11.2 Layout Example .................................................... 78  
12 器件和文档支持 ..................................................... 79  
12.1 文档支持................................................................ 79  
12.2 接收文档更新通知 ................................................. 79  
12.3 社区资源................................................................ 79  
12.4 ....................................................................... 79  
12.5 静电放电警告......................................................... 79  
12.6 Glossary................................................................ 79  
13 机械、封装和可订购信息....................................... 79  
8
4 修订历史记录  
注:之前版本的页码可能与当前版本有所不同。  
Changes from Revision A (May 2016) to Revision B  
Page  
Changed the Device Comparison Table................................................................................................................................. 3  
Added the FOVR latency parameter to the Timing Characteristics table............................................................................. 12  
Added SYSREF Not Present (Subclass 0, 2) section .......................................................................................................... 30  
Changed the number of clock cycles in the Fast OVR section ............................................................................................ 31  
Changed the Register Map................................................................................................................................................... 45  
Deleted register 39h, 3Ah, and 56h ..................................................................................................................................... 45  
Changed Power Supply Recommendations section ........................................................................................................... 75  
Added the Power Sequencing and Initialization section....................................................................................................... 76  
已添加 接收文档更新通知.............................................................................................................................................. 79  
Changes from Original (May 2016) to Revision A  
Page  
已发布为量产数据”................................................................................................................................................................. 1  
2
Copyright © 2016–2017, Texas Instruments Incorporated  
 
ADS54J20  
www.ti.com.cn  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
5 Device Comparison Table  
PART NUMBER  
ADS54J20  
ADS54J42  
ADS54J40  
ADS54J60  
ADS54J66  
ADS54J69  
SPEED GRADE (MSPS)  
RESOLUTION (Bits)  
CHANNEL  
1000  
625  
12  
14  
14  
16  
14  
16  
2
2
2
2
4
2
1000  
1000  
500  
500  
6 Pin Configuration and Functions  
RMP Package  
72-Pin VQFNP  
Top View  
DB3M  
DB3P  
1
54  
53  
52  
51  
50  
49  
48  
47  
46  
45  
44  
43  
42  
41  
40  
39  
38  
37  
DA3M  
DA3P  
DGND  
IOVDD  
PDN  
2
DGND  
IOVDD  
SDIN  
3
4
5
SCLK  
6
RES  
SEN  
7
RESET  
DVDD  
AVDD  
AVDD3V  
AVDD  
AVDD  
INAP  
DVDD  
AVDD  
AVDD3V  
SDOUT  
AVDD  
INBP  
8
9
Thermal  
Pad  
10  
11  
12  
13  
14  
15  
16  
17  
18  
INBM  
INAM  
AVDD  
AVDD3V  
AVDD  
AGND  
AVDD  
AVDD3V  
AVDD  
AGND  
Not to scale  
Copyright © 2016–2017, Texas Instruments Incorporated  
3
ADS54J20  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
www.ti.com.cn  
Pin Functions  
PIN  
I/O  
DESCRIPTION  
NAME  
NO.  
CLOCK, SYSREF  
CLKINM  
28  
27  
34  
33  
I
I
I
I
Negative differential clock input for the ADC  
Positive differential clock input for the ADC  
Negative external SYSREF input  
CLKINP  
SYSREFM  
SYSREFP  
Positive external SYSREF input  
CONTROL, SERIAL  
Power-down. Can be configured via an SPI register setting.  
Can be configured as a fast overrange output for channel A via the SPI.  
PDN  
50  
I/O  
RESET  
SCLK  
SDIN  
48  
6
I
I
I
Hardware reset; active high. This pin has an internal 20-kΩ pulldown resistor.  
Serial interface clock input  
5
Serial interface data input  
Serial interface data output.  
Can be configured as a fast overrange output for channel B via the SPI.  
SDOUT  
11  
7
O
I
SEN  
Serial interface enable  
DATA INTERFACE  
DA0M  
DA1M  
DA2M  
DA3M  
DA0P  
62  
59  
56  
54  
61  
58  
55  
53  
65  
68  
71  
1
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
I
JESD204B serial data negative output for channel A  
DA1P  
JESD204B serial data positive output for channel A  
JESD204B serial data negative output for channel B  
DA2P  
DA3P  
DB0M  
DB1M  
DB2M  
DB3M  
DB0P  
66  
69  
72  
2
DB1P  
JESD204B serial data positive output for channel B  
Synchronization input for the JESD204B port  
DB2P  
DB3P  
SYNC  
INPUT, COMMON MODE  
INAM  
63  
41  
42  
14  
13  
I
I
I
I
Differential analog negative input for channel A  
Differential analog positive input for channel A  
Differential analog negative input for channel B  
Differential analog positive input for channel B  
Common-mode voltage, 2.1 V.  
INAP  
INBM  
INBP  
VCM  
22  
O
Note that analog inputs are internally biased to this pin through 600 Ω (effective), no external  
connection from the VCM pin to the INxP or INxM pin is required.  
POWER SUPPLY  
AGND  
AVDD  
18, 23, 26, 29, 32, 36, 37  
I
I
Analog ground  
9, 12, 15, 17, 25, 30, 35, 38,  
40, 43, 44, 46  
Analog 1.9-V power supply  
AVDD3V  
DGND  
DVDD  
IOVDD  
NC, RES  
NC  
10, 16, 24, 31, 39, 45  
3, 52, 60, 67  
8, 47  
I
I
I
I
Analog 3.0-V power supply for the analog buffer  
Digital ground  
Digital 1.9-V power supply  
4, 51, 57, 64, 70  
Digital 1.15-V power supply for the JESD204B transmitter  
19, 20, 21  
49  
I
Unused pin, do not connect  
RES  
Reserved pin. Connect to DGND.  
4
Copyright © 2016–2017, Texas Instruments Incorporated  
ADS54J20  
www.ti.com.cn  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
7 Specifications  
7.1 Absolute Maximum Ratings  
over operating free-air temperature range (unless otherwise noted)(1)  
MIN  
–0.3  
–0.3  
–0.3  
–0.2  
–0.3  
–0.3  
–0.3  
–0.3  
–0.2  
–65  
MAX  
UNIT  
V
AVDD3V  
3.6  
AVDD  
Supply voltage range  
DVDD  
2.1  
2.1  
IOVDD  
Voltage between AGND and DGND  
INAP, INBP, INAM, INBM  
1.4  
0.3  
3
V
CLKINP, CLKINM  
Voltage applied to input pins  
AVDD + 0.3  
AVDD + 0.3  
2.1  
V
SYSREFP, SYSREFM  
SCLK, SEN, SDIN, RESET, SYNC, PDN  
Storage temperature, Tstg  
150  
°C  
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings  
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended  
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.  
7.2 ESD Ratings  
VALUE  
±1000  
±500  
UNIT  
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)  
Charged-device model (CDM), per JEDEC specification JESD22-C101(2)  
V(ESD)  
Electrostatic discharge  
V
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.  
(2) JEDEC document JEP157 states that 250-V HBM allows safe manufacturing with a standard ESD control process.  
Copyright © 2016–2017, Texas Instruments Incorporated  
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ADS54J20  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
www.ti.com.cn  
7.3 Recommended Operating Conditions  
over operating free-air temperature range (unless otherwise noted)(1)(2)  
MIN  
2.85  
1.8  
NOM  
3.0  
MAX  
UNIT  
AVDD3V  
3.6  
2.0  
2.0  
1.2  
AVDD  
Supply voltage range  
DVDD  
1.9  
V
1.7  
1.9  
IOVDD  
1.1  
1.15  
1.9  
Differential input voltage range  
VPP  
V
Input common-mode voltage  
2.0  
Analog inputs  
Maximum analog input frequency for a 1.9-VPP input  
amplitude(3)(4)  
400  
MHz  
MHz  
Input clock frequency, device clock frequency  
250(5)  
0.75  
0.8  
1000  
Sine wave, ac-coupled  
1.5  
1.6  
Input clock amplitude differential  
Clock inputs  
Temperature  
LVPECL, ac-coupled  
LVDS, ac-coupled  
VPP  
(VCLKP – VCLKM  
)
0.7  
Input device clock duty cycle  
Operating free-air, TA  
45%  
–40  
50%  
55%  
85  
ºC  
Operating junction, TJ  
105(6)  
125  
(1) SYSREF must be applied for the device to initialize; see the SYSREF Signal section for details.  
(2) After power-up, always use a hardware reset to reset the device for the first time; see Table 65 for details.  
(3) Operating 0.5 dB below the maximum-supported amplitude is recommended to accommodate gain mismatch in interleaving ADCs.  
(4) At high frequencies, the maximum supported input amplitude reduces; see Figure 36 for details.  
(5) See Table 10 and Table 12.  
(6) Prolonged use above the nominal junction temperature can increase the device failure-in-time (FIT) rate.  
7.4 Thermal Information  
ADS54J20  
THERMAL METRIC(1)  
RMP (VQFNP)  
UNIT  
72 PINS  
22.3  
5.1  
RθJA  
Junction-to-ambient thermal resistance  
°C/W  
°C/W  
°C/W  
°C/W  
°C/W  
°C/W  
RθJC(top)  
RθJB  
Junction-to-case (top) thermal resistance  
Junction-to-board thermal resistance  
2.4  
ψJT  
Junction-to-top characterization parameter  
Junction-to-board characterization parameter  
Junction-to-case (bottom) thermal resistance  
0.1  
ψJB  
2.3  
RθJC(bot)  
0.4  
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application  
report.  
6
Copyright © 2016–2017, Texas Instruments Incorporated  
 
ADS54J20  
www.ti.com.cn  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
7.5 Electrical Characteristics  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
PARAMETER  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
GENERAL  
ADC sampling rate  
Resolution  
1000 MSPS  
Bits  
12  
POWER SUPPLIES  
AVDD3V  
AVDD  
3.0-V analog supply  
2.85  
1.8  
3.0  
1.9  
3.6  
2.0  
V
V
1.9-V analog supply  
DVDD  
IOVDD  
IAVDD3V  
IAVDD  
1.9-V digital supply  
1.7  
1.9  
2.0  
V
1.15-V SerDes supply  
3.0-V analog supply current  
1.9-V analog supply current  
1.1  
1.15  
334  
359  
197  
1.2  
V
VIN = full-scale on both channels  
VIN = full-scale on both channels  
8 lanes active (LMFS = 8224)  
360  
510  
260  
mA  
mA  
mA  
4 lanes active (LMFS = 4222),  
2X decimation  
197  
mA  
IDVDD  
IIOVDD  
PD  
1.9-V digital supply current  
2 lanes active (LMFS = 2221),  
4X decimation  
176  
566  
593  
mA  
mA  
mA  
8 lanes active (LMFS = 8224)  
920  
3.1  
4 lanes active (LMFS = 4222),  
2X decimation  
1.15-V SerDes supply current  
2 lanes active (LMFS = 2221),  
4X decimation  
562  
2.71  
2.74  
mA  
W
8 lanes active (LMFS = 8224)  
4 lanes active (LMFS = 4222),  
2X decimation  
W
Total power dissipation(1)  
2 lanes active (LMFS = 2221),  
4X decimation  
2.66  
139  
W
Global power-down power dissipation  
315  
mW  
ANALOG INPUTS (INAP, INAM, INBP, INBM)  
Differential input full-scale voltage  
1.9  
2.0  
0.6  
4.7  
VPP  
V
VIC  
RIN  
CIN  
Common-mode input voltage  
Differential input resistance  
Differential input capacitance  
At 170-MHz input frequency  
At 170-MHz input frequency  
kΩ  
pF  
50-Ω source driving ADC inputs  
terminated with 50 Ω  
Analog input bandwidth (3 dB)  
1.2  
GHz  
CLOCK INPUT (CLKINP, CLKINM)  
CLKINP and CLKINM are  
connected to internal biasing  
voltage through 400 Ω  
Internal clock biasing  
1.15  
V
(1) See the Power-Down Mode section for details.  
Copyright © 2016–2017, Texas Instruments Incorporated  
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ADS54J20  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
www.ti.com.cn  
7.6 AC Characteristics  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input amplitude, and  
0-dB digital gain (unless otherwise noted)  
PARAMETER  
TEST CONDITIONS  
fIN = 10 MHz, AIN = –1 dBFS  
MIN  
TYP  
68.4  
68.3  
67.8  
67.4  
67.0  
66.7  
65.8  
66.3  
65.5  
61.5  
155.4  
155.3  
154.8  
154.4  
154.0  
153.7  
152.8  
153.3  
152.5  
148.5  
68.3  
68.1  
67.7  
67.2  
66.7  
66.3  
65.0  
65.7  
64.7  
60.8  
85.0  
83.0  
86.0  
85.0  
81.0  
78.0  
73.0  
72.0  
68.0  
69.0  
MAX  
UNIT  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
64  
SNR  
Signal-to-noise ratio  
dBFS  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
151  
63.2  
74  
NSD  
Noise spectral density  
dBFS/Hz  
dBFS  
dBc  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
Signal-to-noise and  
distortion ratio  
SINAD  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
Spurious-free dynamic range  
(excluding IL spurs)  
SFDR  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
8
Copyright © 2016–2017, Texas Instruments Incorporated  
ADS54J20  
www.ti.com.cn  
ZHCSF28B MAY 2016REVISED JANUARY 2017  
AC Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input amplitude, and  
0-dB digital gain (unless otherwise noted)  
PARAMETER  
TEST CONDITIONS  
fIN = 10 MHz, AIN = –1 dBFS  
MIN  
TYP  
85.0  
90.0  
92.0  
85.0  
81.0  
81.0  
76.0  
72.0  
68.0  
69.0  
85.0  
83.0  
86.0  
87.0  
81.0  
78.0  
73.0  
70.0  
77.0  
79.0  
94.0  
97.0  
93.0  
95.0  
95.0  
91.0  
85.0  
88.0  
80.0  
83.0  
11.1  
11.0  
11.0  
10.9  
10.8  
10.7  
10.5  
10.6  
10.5  
9.8  
MAX  
UNIT  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
74  
Second-order harmonic  
distortion  
HD2  
dBc  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
74  
Third-order harmonic  
distortion  
HD3  
dBc  
dBFS  
Bits  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
77  
Non  
HD2,  
HD3  
Spurious-free dynamic range  
(excluding HD2, HD3, and  
IL spur)  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
10.2  
ENOB  
Effective number of bits  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
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AC Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input amplitude, and  
0-dB digital gain (unless otherwise noted)  
PARAMETER  
TEST CONDITIONS  
fIN = 10 MHz, AIN = –1 dBFS  
MIN  
TYP  
82.0  
80.0  
83.0  
82.0  
78.0  
75.0  
70.0  
71.0  
67.0  
69.0  
84.0  
85.0  
84.0  
83.0  
82.0  
81.0  
81.0  
78.0  
79.0  
82.0  
MAX  
UNIT  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
72  
THD  
Total harmonic distortion  
dBc  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN = 10 MHz, AIN = –1 dBFS  
fIN = 100 MHz, AIN = –1 dBFS  
fIN = 170 MHz, AIN = –1 dBFS  
fIN = 230 MHz, AIN = –1 dBFS  
fIN = 270 MHz, AIN = –1 dBFS  
fIN = 300 MHz, AIN = –1 dBFS  
fIN = 370 MHz, AIN = –1 dBFS  
fIN = 470 MHz, AIN = –3 dBFS  
69  
SFDR_IL Interleaving spur  
dBc  
AIN = –6 dBFS  
fIN = 720 MHz  
AIN = –6 dBFS, gain = 5 dB  
fIN1 = 185 MHz, fIN2 = 190 MHz,  
AIN = –7 dBFS  
85  
79  
Two-tone, third-order  
IMD3  
fIN1 = 365 MHz, fIN2 = 370 MHz,  
AIN = –7 dBFS  
dBFS  
dB  
intermodulation distortion  
fIN1 = 465 MHz, fIN2 = 470 MHz,  
AIN = –7 dBFS  
75  
Crosstalk isolation between  
channel A and B  
Full-scale, 170-MHz signal on aggressor, idle  
channel is victim  
100  
10  
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7.7 Digital Characteristics  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
PARAMETER  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
DIGITAL INPUTS (RESET, SCLK, SEN, SDIN, SYNC, PDN)(1)  
VIH  
VIL  
High-level input voltage  
Low-level input voltage  
All digital inputs support 1.2-V and 1.8-V logic levels  
All digital inputs support 1.2-V and 1.8-V logic levels  
SEN  
0.8  
V
V
0.4  
0
50  
50  
0
IIH  
High-level input current  
Low-level input current  
µA  
µA  
RESET, SCLK, SDIN, PDN, SYNC  
SEN  
IIL  
RESET, SCLK, SDIN, PDN, SYNC  
DIGITAL INPUTS (SYSREFP, SYSREFM)  
VD  
Differential input voltage  
Common-mode voltage for SYSREF(2)  
0.35  
0.45  
1.3  
1.4  
V
V
V(CM_DIG)  
DIGITAL OUTPUTS (SDOUT, PDN(2)  
)
DVDD –  
0.1  
VOH  
VOL  
High-level output voltage  
Low-level output voltage  
DVDD  
V
V
0.1  
DIGITAL OUTPUTS (JESD204B Interface: DxP, DxM)(3)  
VOD  
VOC  
Output differential voltage  
With default swing setting  
700  
450  
mVPP  
mV  
Output common-mode voltage  
Transmitter pins shorted to any voltage between  
–0.25 V and 1.45 V  
Transmitter short-circuit current  
Single-ended output impedance  
Output capacitance  
–100  
100  
mA  
Ω
zos  
50  
2
Output capacitance inside the device,  
from either output to ground  
pF  
(1) The RESET, SCLK, SDIN, and PDN pins have a 20-kΩ (typical) internal pulldown resistor to ground, and the SEN pin has a 20-kΩ  
(typical) pullup resistor to IOVDD.  
(2) When functioning as an OVR pin for channel B.  
(3) 100-Ω differential termination.  
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7.8 Timing Characteristics  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, and –1-dBFS differential input (unless  
otherwise noted)  
MIN  
TYP  
MAX  
UNITS  
SAMPLE TIMING  
Aperture delay  
0.75  
1.6  
ns  
ps  
Aperture delay matching between two channels on the same device  
Aperture delay matching between two devices at the same temperature and supply voltage  
Aperture jitter  
±70  
±270  
120  
ps  
fS rms  
WAKE-UP TIMING  
Wake-up time to valid data after coming out of global power-down  
150  
µs  
LATENCY  
Input  
clock  
cycles  
Data latency(1): ADC sample to digital output  
OVR latency: ADC sample to OVR bit  
134  
62  
Input  
clock  
cycles  
Input  
clock  
cycles  
FOVR latency: ADC sample to FOVR signal on pin  
18 + 4 ns  
4
tPD  
Propagation delay: logic gates and output buffers delay (does not change with fS)  
ns  
SYSREF TIMING  
tSU_SYSREF Setup time for SYSREF, referenced to the input clock falling edge  
300  
100  
900  
ps  
ps  
tH_SYSREF  
Hold time for SYSREF, referenced to the input clock falling edge  
JESD OUTPUT INTERFACE TIMING CHARACTERISTICS  
Unit interval  
100  
2.5  
400  
ps  
Gbps  
ps  
Serial output data rate  
6.25  
Total jitter for BER of 1E-15 and lane rate = 6.25 Gbps  
Random jitter for BER of 1E-15 and lane rate = 6.25 Gbps  
Deterministic jitter for BER of 1E-15 and lane rate = 6.25 Gbps  
26  
0.75  
12  
ps rms  
ps, pk-pk  
Data rise time, data fall time: rise and fall times are measured from 20% to 80%,  
differential output waveform, 2.5 Gbps bit rate 6.25 Gbps  
tR, tF  
35  
ps  
(1) Overall ADC latency = data latency + tPDI  
.
Sample N  
tH_SYSREF  
tSU_SYSREF  
CLKIN  
1.0 GSPS  
SYSREF  
Figure 1. SYSREF Timing  
12  
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N+1  
N+2  
N
N+3  
Sample  
tPD  
Data Latency: 134 Clock Cycles  
CLKINM  
CLKINP  
D
20  
D
11  
D
20  
D
11  
D
20  
DA0P, DA0M,  
DB0P, DB0M  
Sample N-1  
Sample N  
Sample N+1  
Sample N+2  
D
10  
D
1
D
10  
D
1
D
10  
DA1P, DA1M,  
DB1P, DB1M  
Sample N-1  
Sample N  
Sample N+1  
Sample N+2  
Figure 2. Sample Timing Requirements  
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7.9 Typical Characteristics  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
0
-20  
0
-20  
-40  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D001  
D002  
SNR = 68.4 dBFS, SINAD = 68.3 dBFS,  
SNR = 67.9 dBFS, SINAD = 67.8 dBFS,  
THD = 84 dBc, IL spur = 89 dBc, SFDR = 87 dBc,  
non HD2, HD3 spur = 93 dBc  
SFDR = 87 dBc, THD = 85 dBc, IL spur = 88 dBc,  
non HD2, HD3 spur = 96 dBc  
Figure 3. FFT for 10-MHz Input Signal  
Figure 4. FFT for 140-MHz Input Signal  
0
0
-20  
-40  
-20  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D003  
D004  
SNR = 67.8 dBFS, SINAD = 67.7 dBFS,  
SNR = 67.4 dBFS, SINAD = 67.2 dBFS,  
SFDR = 86 dBc, THD = 81 dBc, IL spur = 88 dBc,  
non HD2, HD3 spur = 89 dBc  
IL spur = 87 dBc, SFDR = 84 dBc, THD = 82 dBc,  
non HD2, HD3 spur = 90 dBc  
Figure 5. FFT for 170-MHz Input Signal  
Figure 6. FFT for 230-MHz Input Signal  
0
0
-20  
-40  
-20  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D005  
D006  
SNR = 66.7 dBFS, SINAD = 66.3 dBFS,  
IL spur = 85 dBc, SFDR = 77 dBc, THD = 76 dBc,  
non HD2, HD3 spur = 92 dBc  
SNR = 65.8 dBFS, SINAD = 65 dBFS,  
SFDR = 74 dBc, THD = 72 dBc,  
IL spur = 85 dBc, non HD2, HD3 spur = 86 dBc  
Figure 7. FFT for 300-MHz Input Signal  
Figure 8. FFT for 370-MHz Input Signal  
14  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
0
0
-20  
-20  
-40  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D007  
D008  
SNR = 66.3 dBFS, SINAD = 65.7 dBFS,  
SFDR = 72 dBc, THD = 71 dBc,  
fIN1 = 185 MHz, fIN2 = 190 MHz, each tone at –7 dBFS,  
IMD = 85 dBFS  
IL spur = 81 dBc, non HD2, HD3 spur = 90 dBc  
Figure 9. FFT for 470-MHz Input Signal  
Figure 10. FFT for Two-Tone Input Signal (–7 dBFS)  
0
0
-20  
-40  
-20  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D009  
D010  
fIN1 = 185 MHz, fIN2 = 190 MHz, each tone at –36 dBFS,  
IMD = 103 dBFS  
fIN1 = 370 MHz, fIN2 = 365 MHz, each tone at –7 dBFS,  
IMD = 80 dBFS  
Figure 11. FFT for Two-Tone Input Signal (–36 dBFS)  
Figure 12. FFT for Two-Tone Input Signal (–7 dBFS)  
0
0
-20  
-40  
-20  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D011  
D012  
fIN1 = 370 MHz, fIN2 = 365 MHz, each tone at –36 dBFS,  
IMD = 109 dBFS  
fIN1 = 470 MHz, fIN2 = 465 MHz, each tone at –7 dBFS,  
IMD = 74.9 dBFS  
Figure 13. FFT for Two-Tone Input Signal (–36 dBFS)  
Figure 14. FFT for Two-Tone Input Signal (–7 dBFS)  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
0
-80  
-84  
-20  
-88  
-40  
-92  
-60  
-96  
-80  
-100  
-100  
-120  
-104  
-35  
-31  
-27  
-23  
-19  
-15  
-11  
-7  
0
100  
200  
300  
400  
500  
Each Tone Amplitude (dBFS)  
D014  
Input Frequency (MHz)  
D013  
fIN1 = 185 MHz, fIN2 = 190 MHz  
fIN1 = 470 MHz, fIN2 = 465 MHz, each tone at –36 dBFS,  
IMD = 109.2 dBFS  
Figure 16. Intermodulation Distortion vs Input Amplitude  
(185 MHz and 190 MHz)  
Figure 15. FFT for Two-Tone Input Signal  
(–36 dBFS)  
-76  
-80  
-70  
-74  
-78  
-84  
-82  
-88  
-86  
-90  
-92  
-94  
-96  
-98  
-100  
-104  
-102  
-106  
-35  
-31  
-27  
-23  
-19  
-15  
-11  
-7  
-35  
-31  
-27  
-23  
-19  
-15  
-11  
-7  
Each Tone Amplitude (dBFS)  
Each Tone Amplitude (dBFS)  
D015  
D016  
fIN1 = 365 MHz, fIN2 = 370 MHz  
fIN1 = 465 MHz, fIN2 = 470 MHz  
Figure 17. Intermodulation Distortion vs Input Amplitude  
(365 MHz and 370 MHz)  
Figure 18. Intermodulation Distortion vs Input Amplitude  
(465 MHz and 470 MHz)  
95  
90  
86  
82  
78  
74  
70  
AIN = -6 dBFS  
AIN = -3 dBFS  
AIN = -1 dBFS  
90  
85  
80  
75  
70  
65  
60  
55  
0
100  
200  
300  
400  
500  
600  
700  
0
40 80 120 160 200 240 280 320 360 400 440 480  
Input Frequency (MHz)  
Input Frequency (MHz)  
D043  
D018  
Figure 19. Spurious-Free Dynamic Range vs  
Input Frequency  
Figure 20. Interleaving Spur vs Input Frequency  
16  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
71  
70  
69  
68  
67  
66  
65  
71  
70.5  
70  
AIN = -6 dBFS  
AIN = -3 dBFS  
AIN = -1 dBFS  
AVDD = 1.8 V  
AVDD = 1.85 V  
AVDD = 1.9 V  
AVDD = 1.95 V  
AVDD = 2 V  
69.5  
69  
68.5  
68  
67.5  
67  
0
100  
200  
300  
400  
500  
600  
700  
-40  
-15  
10  
35  
60  
85  
Input Frequency (MHz)  
Temperature (°C)  
D042  
D020  
fIN = 170 MHz  
Figure 21. Signal-to-Noise Ratio vs Input Frequency  
Figure 22. Signal-to-Noise Ratio vs  
AVDD Supply and Temperature  
94  
72  
71  
70  
69  
68  
67  
66  
65  
64  
AVDD = 1.8 V  
AVDD = 1.85 V  
AVDD = 1.9 V  
AVDD = 1.95 V  
AVDD = 2 V  
AVDD = 1.8 V  
AVDD = 1.85 V  
AVDD = 1.9 V  
AVDD = 1.95 V  
AVDD = 2 V  
92  
90  
88  
86  
84  
82  
80  
78  
-40  
-15  
10  
35  
60  
85  
-40  
-15  
10  
35  
60  
85  
Temperature (°C)  
Temperature (°C)  
D021  
D022  
fIN = 170 MHz  
fIN = 350 MHz  
Figure 23. Spurious-Free Dynamic Range vs  
AVDD Supply and Temperature  
Figure 24. Signal-to-Noise Ratio vs  
AVDD Supply and Temperature  
79  
78  
77  
76  
75  
74  
73  
71  
AVDD = 1.8 V  
AVDD = 1.85 V  
AVDD = 1.9 V  
AVDD = 1.95 V  
AVDD = 2 V  
DVDD = 1.75 V  
DVDD = 1.8 V  
DVDD = 1.85 V  
DVDD = 1.9 V  
DVDD = 1.95 V  
DVDD = 2 V  
70.2  
69.4  
68.6  
67.8  
67  
-40  
-15  
10  
35  
60  
85  
-40  
-15  
10  
35  
60  
85  
Temperature (°C)  
Temperature (°C)  
D023  
D024  
fIN = 350 MHz  
fIN = 170 MHz  
Figure 25. Spurious-Free Dynamic Range vs  
AVDD Supply and Temperature  
Figure 26. Signal-to-Noise Ratio vs  
DVDD Supply and Temperature  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
92  
90  
88  
86  
84  
82  
70  
69  
68  
67  
66  
65  
64  
DVDD = 1.75 V  
DVDD = 1.8 V  
DVDD = 1.85 V  
DVDD = 1.9 V  
DVDD = 1.95 V  
DVDD = 2 V  
DVDD = 1.75 V  
DVDD = 1.8 V  
DVDD = 1.85 V  
DVDD = 1.9 V  
DVDD = 1.95 V  
DVDD = 2 V  
-40  
-15  
10  
35  
60  
85  
-40  
-15  
10  
35  
60  
85  
Temperature (°C)  
Temperature (°C)  
D025  
D026  
fIN = 170 MHz  
fIN = 350 MHz  
Figure 27. Spurious-Free Dynamic Range vs  
DVDD Supply and Temperature  
Figure 28. Signal-to-Noise Ratio vs  
DVDD Supply and Temperature  
70  
82  
80  
78  
76  
74  
72  
DVDD = 1.75 V  
DVDD = 1.8 V  
DVDD = 1.85 V  
DVDD = 1.9 V  
DVDD = 1.95 V  
DVDD = 2 V  
AVDD3V = 2.85 V  
AVDD3V = 3 V  
AVDD3V = 3.1 V  
AVDD3V = 3.2 V  
AVDD3V = 3.3 V  
AVDD3V = 3.4 V  
AVDD3V = 3.5 V  
AVDD3V = 3.6 V  
69.5  
69  
68.5  
68  
67.5  
67  
-40  
-15  
10  
35  
60  
85  
-40  
-15  
10  
35  
60  
85  
Temperature (°C)  
Temperature (°C)  
D027  
D028  
fIN = 350 MHz  
fIN = 170 MHz  
Figure 29. Spurious-Free Dynamic Range vs  
DVDD Supply and Temperature  
Figure 30. Signal-to-Noise Ratio vs  
AVDD3V Supply and Temperature  
71  
70  
69  
68  
67  
66  
65  
64  
94  
92  
90  
88  
86  
84  
82  
80  
AVDD3V = 2.85 V  
AVDD3V = 3 V  
AVDD3V = 3.1 V  
AVDD3V = 3.2 V  
AVDD3V = 3.3 V  
AVDD3V = 3.4 V  
AVDD3V = 3.5 V  
AVDD3V = 3.6 V  
AVDD3V = 2.85 V  
AVDD3V = 3 V  
AVDD3V = 3.1 V  
AVDD3V = 3.2 V  
AVDD3V = 3.3 V  
AVDD3V = 3.4 V  
AVDD3V = 3.5 V  
AVDD3V = 3.6 V  
-40  
-15  
10  
35  
60  
85  
-40  
-15  
10  
35  
60  
85  
Temperature (°C)  
Temperature (°C)  
D030  
D029  
fIN = 350 MHz  
fIN = 170 MHz  
Figure 32. Signal-to-Noise Ratio vs  
AVDD3V Supply and Temperature  
Figure 31. Spurious-Free Dynamic Range vs  
AVDD3V Supply and Temperature  
18  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
82  
80  
78  
76  
74  
72  
79  
76  
73  
70  
67  
64  
61  
58  
55  
AVDD3V = 2.85 V  
AVDD3V = 3 V  
AVDD3V = 3.1 V  
AVDD3V = 3.2 V  
AVDD3V = 3.3 V  
AVDD3V = 3.4 V  
AVDD3V = 3.5 V  
AVDD3V = 3.6 V  
Gain = 0 dB  
Gain = 2 dB  
Gain = 4 dB  
Gain = 6 dB  
Gain = 8 dB  
Gain = 10 dB  
Gain = 12 dB  
-40  
-15  
10  
35  
60  
85  
10  
102  
194  
286  
378  
470  
Temperature (°C)  
Input Frequency (MHz)  
D031  
D053  
fIN = 350 MHz  
Figure 33. Spurious-Free Dynamic Range vs  
AVDD3V Supply and Temperature  
Figure 34. Signal-to-Noise Ratio vs  
Gain and Input Frequency  
110  
105  
100  
95  
2
Gain = 0 dB  
Gain = 2 dB  
Gain = 4 dB  
Gain = 6 dB  
Gain = 8 dB  
Gain = 10 dB  
Gain = 12 dB  
0
-2  
90  
-4  
85  
80  
-6  
75  
-8  
70  
65  
-10  
10  
102  
194  
286  
378  
470  
0
100 200 300 400 500 600 700 800 900 1000  
Input Frequency (MHz)  
Input Frequency (MHz)  
D054  
D046  
Figure 35. Spurious-Free Dynamic Range vs  
Gain and Input Frequency  
Figure 36. Maximum Supported Amplitude vs Frequency  
73  
71  
69  
67  
65  
63  
150  
SNR (dBFS)  
SFDR (dBc)  
73.5  
72  
210  
180  
150  
120  
90  
SNR (dBFS)  
SFDR (dBc)  
SFDR (dBFS)  
SFDR (dBFS)  
120  
70.5  
69  
90  
60  
30  
0
67.5  
66  
60  
64.5  
63  
30  
0
-70  
-60  
-50  
-40  
-30  
-20  
-10  
0
-70  
-60  
-50  
-40  
-30  
-20  
-10  
0
Amplitude (dBFS)  
Amplitude (dBFS)  
D032  
D033  
fIN = 170 MHz  
fIN = 350 MHz  
Figure 37. Performance vs Input Amplitude  
Figure 38. Performance vs Input Amplitude  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
74  
72  
70  
68  
66  
64  
100  
90  
80  
70  
60  
50  
75  
72  
69  
66  
63  
60  
125  
100  
75  
50  
25  
0
SNR  
SFDR  
SNR  
SFDR  
0.2  
0.6  
1
1.4  
1.8  
2.2  
0.2  
0.6  
1
1.4  
1.8  
2.2  
Differential Clock Amplitude (Vpp)  
Differential Clock Amplitude (Vpp)  
D034  
D035  
fIN = 170 MHz  
fIN = 350 MHz  
Figure 39. Performance vs Sampling Clock Amplitude  
Figure 40. Performance vs Sampling Clock Amplitude  
(Differential)  
71  
70  
69  
68  
67  
66  
95  
90  
85  
80  
75  
70  
71  
70  
69  
68  
67  
66  
65  
64  
88  
84  
80  
76  
72  
68  
64  
60  
SNR  
SFDR  
SNR  
SFDR  
30  
35  
40  
45  
50  
55  
60  
65  
70  
30  
35  
40  
45  
50  
55  
60  
65  
70  
Input Clock Duty Cycle (%)  
Input Clock Duty Cycle (%)  
D036  
D037  
fIN = 170 MHz  
fIN = 350 MHz  
Figure 41. Performance vs Clock Duty Cycle  
Figure 42. Performance vs Clock Duty Cycle  
0
-20  
-10  
-15  
-20  
-25  
-30  
-35  
-40  
-45  
-50  
-55  
-60  
PSRR with 25-mVpp Signal on AVDD  
PSRR with 50-mVpp Signal on AVDD3V  
-40  
-60  
-80  
-100  
-120  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
0
50  
100  
150  
200  
250  
300  
D039  
Frequency of Signal on Supply (MHz)  
D038  
SNR = 66.7 dBFS, SINAD = 65.7 dBFS,  
SFDR = 79 dBc, fIN = 170.1 MHz,  
fPSRR = 5 MHz, non HD2, HD3 spur = 84 dBc  
Figure 44. Power-Supply Rejection Ratio FFT for  
Test Signals on the AVDD Supply  
Figure 43. Power-Supply Rejection Ratio vs Supply Signal  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
-20  
-25  
-30  
-35  
-40  
-45  
-50  
-55  
0
-20  
-40  
-60  
-80  
-100  
-120  
0
50  
100  
150  
200  
250  
300  
0
100  
200  
300  
400  
500  
Frequency of Input Common-Mode Signal (MHz)  
Input Frequency (MHz)  
D040  
D041  
Figure 45. Common-Mode Rejection Ratio vs Signal  
Frequency  
Figure 46. Common-Mode Rejection Ratio FFT  
4
3.5  
3
800  
700  
600  
500  
400  
300  
200  
100  
2.78  
I DVDD (mA)  
I AVDD (mA)  
I IOVDD (mA)  
I AVDD3 (mA)  
Total Power (W)  
2.76  
2.74  
2.72  
2.7  
2.5  
2
2.68  
2.66  
2.64  
1.5  
1
500 550 600 650 700 750 800 850 900 950 1000  
-40  
-15  
10  
35  
60  
85  
Sampling Speed (MSPS)  
Temperature (°C)  
D042  
D045  
Figure 47. Power Consumption vs Sampling Speed  
Figure 48. Power vs Temperature  
0
0
-20  
-40  
-20  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
Input Frequency (MHz)  
Input Frequency (MHz)  
D047  
D048  
SNR = 70.5 dBFS, SINAD = 69.9 dBFS,  
SNR = 70.2 dBFS, SINAD = 69.6 dBFS,  
fS = 250 MHz, fIN = 60 MHz, SFDR = 88.6 dBc,  
THD = 83 dBc, non HD2, HD3 spur = 99.96 dBc  
fS = 250 MHz, fIN = 170 MHz, SFDR = 87 dBc,  
non HD2, HD3 spur = 90.42 dBc  
Figure 49. FFT for 60-MHz Input Signal in  
Decimate-by-4 Mode  
Figure 50. FFT for 170-MHz Input Signal in  
Decimate-by-4 Mode  
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Typical Characteristics (continued)  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
0
0
-20  
-20  
-40  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
Input Frequency (MHz)  
Input Frequency (MHz)  
D049  
D050  
SNR = 69.3 dBFS, SINAD = 68.6 dBFS,  
SNR = 67.6 dBFS, SINAD = 66.8 dBFS,  
fS = 250 MHz, fIN = 300 MHz, SFDR = 86 dBc,  
non HD2, HD3 spur = 94.42 dBc  
fS = 250 MHz, fIN = 450 MHz, SFDR = 83 dBc,  
non HD2, HD3 spur = 90.44 dBc  
Figure 51. FFT for 300-MHz Input Signal in  
Decimate-by-4 Mode  
Figure 52. FFT for 450-MHz Input Signal in  
Decimate-by-4 Mode  
0
0
-20  
-40  
-20  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
50  
100  
150  
200  
250  
0
50  
100  
150  
200  
250  
Input Frequency (MHz)  
Input Frequency (MHz)  
D051  
D052  
SNR = 68.9 dBFS, SINAD = 68.2 dBFS,  
SNR = 66.7 dBFS, SINAD = 65.9 dBFS,  
fS = 500 MHz, fIN = 170 MHz, SFDR = 86 dBc,  
non HD2, HD3 spur = 81.94 dBc  
fS = 500 MHz, fIN = 350 MHz, SFDR = 80 dBc,  
non HD2, HD3 spur = 80.83 dBc  
Figure 53. FFT for 170-MHz Input Signal in  
Decimate-by-2 Mode  
Figure 54. FFT for 350-MHz Input Signal in  
Decimate-by-2 Mode  
22  
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7.10 Typical Characteristics: Contour  
typical values are at TA = 25°C, full temperature range is from TMIN = –40°C to TMAX = +85°C, ADC sampling rate = 1.0 GSPS,  
50% clock duty cycle, AVDD3V = 3.0 V, AVDD = DVDD = 1.9 V, IOVDD = 1.15 V, –1-dBFS differential input, and 0-dB digital  
gain (unless otherwise noted)  
1000  
950  
900  
850  
800  
750  
700  
69.0  
68.5  
68.0  
67.5  
67.0  
66.5  
66.0  
65.5  
65.0  
1000  
950  
900  
850  
800  
750  
700  
90  
87  
84  
81  
78  
75  
72  
69  
66  
0
50  
100 150 200 250 300 350 400 450  
Input Fre que ncy (MHz)  
0
50  
100 150 200 250 300 350 400 450  
Input Fre que ncy (MHz)  
Figure 55. Signal-to-Noise-Ratio with  
0-dB Digital Gain  
Figure 56. Spurious-Free Dynamic Range with  
0-dB Digital Gain  
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8 Detailed Description  
8.1 Overview  
The ADS54J20 is a low-power, wide-bandwidth, 12-bit, 1.0-GSPS, dual-channel, analog-to-digital converter  
(ADC). The ADS54J20 employs four interleaving ADCs for each channel to achieve a noise floor of  
–157 dBFS/Hz. The ADS54J20 uses TI's proprietary interleaving and dither algorithms to achieve a clean  
spectrum with a high spurious-free dynamic range (SFDR). The device also offers various programmable  
decimation filtering options for systems requiring higher signal-to-noise ratio (SNR) and SFDR over a wide range  
of frequencies.  
Analog input buffers isolate the ADC driver from glitch energy generated from sampling process, thereby  
simplifying the driving network on-board. The JESD204B interface reduces the number of interface lines with  
two-lane and four-lane options, allowing for a high system integration density. The JESD204B interface operates  
in subclass 1, enabling multi-chip synchronization with the SYSREF input.  
8.2 Functional Block Diagram  
DA0P, DA0M,  
DA1P, DA1M  
DDC Block:  
2X, 4X Decimation  
Mixer: fS / 16, fS / 4  
Buffer  
Digital Block  
ADC  
Interleaving  
Correction  
INAP, INAM  
DA2P, DA2M,  
DA3P, DA3M  
PLL:  
x20  
x40  
Divide-  
by-4  
CLKINP,  
CLKINM  
SYNC  
SYSREFP,  
SYSREFM  
DDC Block:  
2X, 4X Decimation  
Mixer: fS / 16, fS / 4  
DB0P, DB0M,  
DB1P, DB1M  
Buffer  
Digital Block  
ADC  
Interleaving  
Correction  
INBP, INBM  
DB2P, DB2M,  
DB3P, DB3M  
FOVR  
Control and SPI  
Common  
Mode  
VCM  
TI Device  
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8.3 Feature Description  
8.3.1 Analog Inputs  
The ADS54J20 analog signal inputs are designed to be driven differentially. The analog input pins have internal  
analog buffers that drive the sampling circuit. Resulting from the analog buffer, the input pins present a high  
impedance input across a very wide frequency range to the external driving source that enables great flexibility in  
the external analog filter design as well as excellent 50-matching for RF applications. The buffer also helps  
isolate the external driving circuit from the internal switching currents of the sampling circuit, resulting in a more  
constant SFDR performance across input frequencies.  
The common-mode voltage of the signal inputs is internally biased to VCM using 600-Ω resistors, allowing for ac-  
coupling of the input drive network. Each input pin (INP, INM) must swing symmetrically between (VCM +  
0.475 V) and (VCM – 0.475 V), resulting in a 1.9-VPP (default) differential input swing. The input sampling circuit  
has a 3-dB bandwidth that extends up to 1.2 GHz. An equivalent analog input network diagram is shown in  
Figure 57.  
0.77 W  
1 W  
3.3 W  
2 nH  
0.6 W  
150 fF  
200 fF  
3 pF  
375 fF  
375 fF  
375 fF  
375 fF  
INP  
40 W  
500 fF  
150 fF  
0.77 W  
1 W  
3.3 W  
600 W  
150 fF  
200 fF  
3 pF  
VCM  
40 W  
600 W  
0.77 W  
1 W  
3.3 W  
150 fF  
200 fF  
3 pF  
2 nH  
0.6 W  
INM  
40 W  
500 fF  
150 fF  
0.77 W  
1 W  
3.3 W  
150 fF  
200 fF  
3 pF  
40 W  
TI Device  
Copyright © 2016, Texas Instruments Incorporated  
Figure 57. Analog Input Network  
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Feature Description (continued)  
The input bandwidth shown in Figure 58 is measured with respect to a 50-Ω differential input termination at the  
ADC input pins.  
0
-3  
-6  
-9  
-12  
-15  
-18  
0
200 400 600 800 1000 1200 1400 1600 1800 2000  
Input Frequency (MHz)  
D056  
Figure 58. Transfer Function versus Frequency  
8.3.2 DDC Block  
The ADS54J20 has an optional digital down-converter (DDC) block that can be enabled via an SPI register write.  
Each ADC channel is followed by a DDC block consisting of three different decimate-by-2 and decimate-by-4  
finite impulse response (FIR) half-band filter options. The different decimation filter options can be selected via  
SPI programming.  
Figure 59 shows the signal processing done inside the DDC block of the ADS54J20.  
Default 12-Bit Data (At 1.0 GSPS)  
Decimate-by-2 Data (At 500 MSPS)  
LPF  
BPF  
2
4
Decimate-by-4 Data (At 250 MSPS)  
Interleaving  
Engine,  
Digital  
Features  
1.0 GSPS  
Data, x(n)  
Ch X  
To JESD  
Encoder  
4
LPF  
Decimate-by-4, I-Data (At 250 MSPS)  
cos(2 n Œ fmix / fS)(1)  
sin(2 n Œ fmix / fS)(1)  
Decimate-by-4 Q-Data (At 250 MSPS)  
4
LPF  
Mode Selection Using  
DECFIL MODE[3:0] Register Bits  
Copyright © 2016, Texas Instruments Incorporated  
(1) In IQ decimate-by-4 mode, the mixer frequency is fixed at fmix = fS / 4. For fS = 1.0 GSPS and fmix = 250 MHz.  
Figure 59. DDC Block  
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Feature Description (continued)  
8.3.2.1 Decimate-by-2 Filter  
This decimation filter has 41 taps. The stop-band attenuation is approximately 90 dB and the pass-band flatness  
is ±0.05 dB. Table 1 shows corner frequencies for the low-pass and high-pass filter options.  
Table 1. Corner Frequencies for the Decimate-by-2 Filter  
CORNERS (dB)  
LOW PASS  
0.202 × fS  
0.210 × fS  
0.215 × fS  
0.227 × fS  
HIGH PASS  
0.298 × fS  
0.290 × fS  
0.285 × fS  
0.273 × fS  
–0.1  
–0.5  
–1  
–3  
Figure 60 and Figure 61 show the frequency response of the decimate-by-2 filter from dc to fS / 2.  
5
-20  
0.5  
0
-0.5  
-1  
-45  
-1.5  
-2  
-70  
-95  
-2.5  
-3  
-120  
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5  
Frequency Response  
0
0.05  
0.1  
0.15  
0.2  
0.25  
Frequency Response  
D013  
D014  
Figure 60. Decimate-by-2 Filter Response  
Figure 61. Decimate-by-2 Filter Response (Zoomed)  
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8.3.2.2 Decimate-by-4 Filter Using a Digital Mixer  
This band-pass decimation filter consists of a digital mixer and three concatenated FIR filters with a combined  
latency of approximately 28 output clock cycles. The alias-band attenuation is approximately 55 dB and the pass-  
band flatness is ±0.1 dB. By default after reset, the band-pass filter is centered at fS / 16. Using the SPI, the  
center frequency can be programmed at N × fS / 16 (where N = 1, 3, 5, or 7). Table 2 shows corner frequencies  
for two extreme options.  
Table 2. Corner frequencies for the Decimate-by-4 Filter  
CORNER FREQUENCY AT LOWER SIDE  
(Center Frequency fS / 16)  
CORNER FREQUENCY AT HIGHER SIDE  
(Center Frequency fS / 16)  
CORNERS (dB)  
–0.1  
–0.5  
–1  
0.011 × fS  
0.010 × fS  
0.008 × fS  
0.006 × fS  
0.114 × fS  
0.116 × fS  
0.117 × fS  
0.120 × fS  
–3  
Figure 62 and Figure 63 show the frequency response of the decimate-by-4 filter for center frequencies fS / 16  
and 3 × fS / 16 (N = 1 and N = 3, respectively).  
10  
0
0.2  
0.1  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-0.1  
-0.2  
-0.3  
-0.4  
-0.5  
-0.6  
-0.7  
-0.8  
-0.9  
-1  
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5  
Frequency Response  
0
0.05  
0.1  
0.15  
0.2  
0.25  
Frequency Response  
D015  
D016  
Figure 62. Decimate-by-4 Filter Response  
Figure 63. Decimate-by-4 Filter Response (Zoomed)  
8.3.2.3 Decimate-by-4 Filter with IQ Outputs  
In this configuration, the DDC block includes a fixed digital fS / 4 mixer. Thus, the IQ pass band is approximately  
±0.11 fS, centered at fS / 4. This decimation filter has 41 taps with a latency of approximately ten output clock  
cycles. The stop-band attenuation is approximately 90 dB and the pass-band flatness is ±0.05 dB. Table 3 shows  
the corner frequencies for a low-pass, decimate-by-4 IQ filter.  
Table 3. Corner Frequencies for a Decimate-by-4 IQ Output Filter  
CORNERS (dB)  
LOW PASS  
0.107 × fS  
0.112 × fS  
0.115 × fS  
0.120 × fS  
–0.1  
–0.5  
–1  
–3  
28  
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Figure 64 and Figure 65 show the frequency response of a decimate-by-4 IQ output filter from dc to fS / 2.  
5
-20  
0.5  
0
-0.5  
-1  
-45  
-1.5  
-2  
-70  
-95  
-2.5  
-3  
-120  
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5  
Frequency Response  
0
0.025  
0.05  
0.075  
0.1  
0.125  
D012  
Frequency Response  
D011  
Figure 64. Decimate-by-4 IQ Output Filter Response  
Figure 65. Decimate-by-4 IQ Output Filter Response  
(Zoomed)  
8.3.3 SYSREF Signal  
The SYSREF signal is a periodic signal that is sampled by the ADS54J20 device clock and used to align the  
boundary of the local multiframe clock inside the data converter. SYSREF is required to be a sub-harmonic of the  
local multiframe clock (LMFC) internal timing. To meet this requirement, the timing of SYSREF is dependent on  
the device clock frequency and the LMFC frequency, as determined by the selected DDC decimation and frames  
per multiframe settings. The SYSREF signal is recommended to be a low-frequency signal in the range of 1 MHz  
to 5 MHz to reduce coupling to the signal path both on the printed circuit board (PCB) as well as internal to the  
device.  
The external SYSREF signal must be a sub-harmonic of the internal LMFC clock, as shown in Equation 1 and  
Table 4.  
SYSREF = LMFC / 2N  
where  
N = 0, 1, 2, and so forth  
(1)  
Table 4. LMFSC Clock Frequency  
LMFS CONFIGURATION  
DECIMATION  
LMFC CLOCK(1)(2)  
fS / K  
4211  
4244  
8224  
4222  
2242  
2221  
2441  
4421  
1241  
(fS / 4) / K  
(fS / 4) / K  
(fS / 4) / K  
(fS / 4) / K  
(fS / 4) / K  
(fS / 4) / K  
(fS / 4) / K  
(fS / 4) / K  
2X  
2X  
4X  
4X (IQ)  
4X (IQ)  
4X  
(1) K = Number of frames per multiframe (JESD digital page 6900h, address 06h, bits 4-0).  
(2) fS = sampling (device) clock frequency.  
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For example, if LMFS = 8224, the default value of K is 8 + 1 = 9 (the actual value for K = the value set in the SPI  
register + 1). If the device clock frequency is fS = 1.0 GSPS, then the local multiframe clock frequency becomes  
(1000 / 4) / 9 = 27.778 MHz. The SYSREF signal frequency can be chosen as LMFC frequency / 8 =  
3.47222 MHz.  
8.3.3.1 SYSREF Not Present (Subclass 0, 2)  
A SYSREF pulse is required by the ADS54J20 to reset internal counters. If SYSREF is not present, as can be  
the case in subclass 0 or 2, this pulse can be done by doing the following register writes shown in Table 5.  
Table 5. Internally Pulsing SYSREF Twice Using Register Writes  
ADDRESS (Hex)  
0-011h  
DATA (Hex)  
80h  
COMMENT  
Set the master page  
Enable manual SYSREF  
Set SYSREF high  
Set SYSREF low  
0-054h  
80h  
0-053h  
01h  
0-053h  
00h  
0-053h  
01h  
Set SYSREF high  
Set SYSREF low  
0-053h  
00h  
30  
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8.3.4 Overrange Indication  
The ADS54J20 provides a fast overrange indication that can be presented in the digital output data stream via  
SPI configuration. Alternatively, if not used, the SDOUT (pin 11) and PDN (pin 50) pins can be configured via the  
SPI to output the fast OVR indicator.  
The JESD 8b, 10b encoder receives 16-bit data that are formed by 12-bit ADC data padded with four 0s as  
LSBs. When the FOVR indication is embedded in the output data stream, the LSB of the 16-bit data stream  
going to the 8b, 10b encoder is replaced, as shown in Figure 66.  
16-Bit Data Output (12-Bit ADC Data Padded with Four 0s)  
D0,  
OVR  
D11  
D10  
D9  
D8  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0
0
0
16-Bit Data Going to 8b, 10b Encoder  
Figure 66. Overrange Indication in a Data Stream  
8.3.4.1 Fast OVR  
The fast OVR is triggered if the input voltage exceeds the programmable overrange threshold and is presented  
after only 18 clock cycles + tPD (tPD of the gates and buffers is approximately 4 ns), thus enabling a quicker  
reaction to an overrange event.  
The input voltage level that the overload is detected at is referred to as the threshold. The threshold is  
programmable using the FOVR THRESHOLD bits, as shown in Figure 67. The FOVR is triggered 18 clock cycles  
+ tPD (tPD of the gates and buffers is approximately 4 ns) after the overload condition occurs.  
0
-5  
-10  
-15  
-20  
-25  
-30  
-35  
-40  
-45  
-50  
0
32  
64  
96  
128  
160  
192  
224  
255  
Threshold Decimal Value  
D055  
Figure 67. Programming Fast OVR Thresholds  
The input voltage level that the fast OVR is triggered at is defined by Equation 2:  
Full-Scale × [Decimal Value of the FOVR Threshold Bits] / 255)  
(2)  
(3)  
The default threshold is E3h (227d), corresponding to a threshold of –1 dBFS.  
In terms of full-scale input, the fast OVR threshold can be calculated as Equation 3:  
20log (FOVR Threshold / 255)  
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8.3.5 Power-Down Mode  
The ADS54J20 provides a highly-configurable power-down mode. Power-down can be enabled using the PDN  
pin or SPI register writes.  
A power-down mask can be configured that allows a trade-off between wake-up time and power consumption in  
power-down mode. Two independent power-down masks can be configured: MASK 1 and MASK 2, as shown in  
Table 6. See the master page registers in Table 15 for further details.  
Table 6. Register Addresses for Power-Down Modes  
REGISTER  
ADDRESS  
REGISTER DATA  
COMMENT  
A[7:0] (Hex)  
MASTER PAGE (80h)  
20  
7
6
5
4
3
2
1
0
PDN ADC CHA  
PDN BUFFER CHB  
PDN ADC CHA  
PDN BUFFER CHB  
GLOBAL OVERRIDE  
PDN ADC CHB  
MASK 1  
21  
23  
24  
PDN BUFFER CHA  
PDN BUFFER CHA  
0
0
0
0
PDN ADC CHB  
MASK 2  
CONFIG  
0
0
0
0
0
0
0
0
PDN MASK  
26  
0
PDN  
PDN PIN  
SEL  
MASK  
SYSREF  
53  
55  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PDN MASK  
To save power, the device can be put in complete power-down by using the GLOBAL PDN register bit. However,  
when JESD is required to remain active when putting the device in power-down, the ADC and analog buffer can  
be powered down by using the PDN ADC CHx and PDN BUFFER CHx register bits after enabling the PDN  
MASK register bit. The PDN MASK SEL register bit can be used to select between MASK 1 or MASK 2. Table 7  
shows the power consumption for different combinations of the GLOBAL PDN, PDN ADC CHx, and PDN BUFF  
CHx register bits.  
Table 7. Power Consumption in Different Power-Down Settings  
TOTAL  
IAVDD3V  
(mA)  
IAVDD  
(mA)  
IDVDD  
(mA)  
IIOVDD  
(mA)  
POWER  
(W)  
REGISTER BIT  
Default  
COMMENT  
After reset, with a full-scale input signal to both  
channels  
247  
3
260  
6
137  
23  
382  
192  
1.94  
0.28  
GBL PDN = 1  
The device is in a complete power-down state  
GBL PDN = 0,  
PDN ADC CHx = 1  
(x = A or B)  
The ADC of one channel is powered down  
206  
195  
166  
258  
97  
367  
381  
1.54  
1.78  
GBL PDN = 0,  
PDN BUFF CHx = 1  
(x = A or B)  
The input buffer of one channel is powered down  
137  
GBL PDN = 0,  
PDN ADC CHx = 1,  
PDN BUFF CHx = 1  
(x = A or B)  
The ADC and input buffer of one channel are  
powered down  
152  
55  
166  
70  
97  
56  
363  
356  
1.37  
0.81  
GBL PDN = 0,  
PDN ADC CHx = 1,  
PDN BUFF CHx = 1  
(x = A and B)  
The ADC and input buffer of both channels are  
powered down  
32  
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8.4 Device Functional Modes  
8.4.1 Device Configuration  
The ADS54J20 can be configured by using a serial programming interface, as described in the Serial Interface  
section. In addition, the device has one dedicated parallel pin (PDN) for controlling the power-down mode.  
The ADS54J20 supports a 24-bit (16-bit address, 8-bit data) SPI operation and uses paging (see the Register  
Maps section) to access all register bits.  
8.4.1.1 Serial Interface  
The ADC has a set of internal registers that can be accessed by the serial interface formed by the SEN (serial  
interface enable), SCLK (serial interface clock), and SDIN (serial interface data) pins, as shown in Figure 68. SPI  
bits in Figure 68 are explained in Table 8. Serially shifting bits into the device is enabled when SEN is low. Serial  
data on SDIN are latched at every SCLK rising edge when SEN is active (low). The interface can function with  
SCLK frequencies from 2 MHz down to very low speeds (of a few Hertz) and also with a non-50% SCLK duty  
cycle.  
Register Address[11:0]  
Register Data[7:0]  
SDIN  
R/W  
M
P
CH  
A11  
A10  
A9  
A8  
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
tDH  
D0  
tSCLK  
tDSU  
SCLK  
SEN  
tSLOADS  
tSLOADH  
RESET  
Figure 68. SPI Timing Diagram  
Table 8. SPI Timing Diagram Legend  
SPI BITS  
DESCRIPTION  
BIT SETTINGS  
0 = SPI write  
1 = SPI read back  
R/W  
Read/write bit  
0 = Analog SPI bank (master and ADC pages)  
1 = JESD SPI bank (main digital, JESD analog, and  
JESD digital pages)  
M
SPI bank access  
JESD page selection bit  
0 = Page access  
1 = Register access  
P
0 = Channel A  
1 = Channel B  
By default, both channels are being addressed.  
SPI access for a specific channel of the JESD SPI  
bank  
CH  
A[11:0]  
D[7:0]  
SPI address bits  
SPI data bits  
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Table 9 shows the timing requirements for the serial interface signals in Figure 68.  
Table 9. SPI Timing Requirements  
MIN  
TYP  
MAX  
UNIT  
MHz  
ns  
fSCLK  
tSLOADS  
tSLOADH  
tDSU  
SCLK frequency (equal to 1 / tSCLK  
SEN to SCLK setup time  
SCLK to SEN hold time  
SDIN setup time  
)
> dc  
100  
100  
100  
100  
2
ns  
ns  
tDH  
SDIN hold time  
ns  
8.4.1.2 Serial Register Write: Analog Bank  
The analog SPI bank contains two pages (the master and ADC pages). The internal register of the ADS54J20  
analog SPI bank can be programmed by:  
1. Driving the SEN pin low.  
2. Initiating a serial interface cycle specifying the page address of the register whose content must be written.  
Master page: write address 0011h with 80h.  
ADC page: write address 0011h with 0Fh.  
3. Writing the register content as shown in Figure 69. When a page is selected, multiple writes into the same  
page can be done.  
Register Address[11:0]  
Register Data[7:0]  
0
0
0
0
SDIN  
SCLK  
R/W  
M
P
CH A11 A10  
A9  
A8  
A7 A6 A5 A4  
A3  
A2  
A1  
A0  
D7  
D6  
D5 D4 D3 D2  
D1  
D0  
SEN  
RESET  
Figure 69. Serial Register Write Timing Diagram  
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8.4.1.3 Serial Register Readout: Analog Bank  
The content from one of the two analog banks can be read out by:  
1. Driving the SEN pin low.  
2. Selecting the page address of the register whose content must be read.  
Master page: write address 0011h with 80h.  
ADC page: write address 0011h with 0Fh.  
3. Setting the R/W bit to 1 and writing the address to be read back.  
4. Reading back the register content on the SDOUT pin, as shown in Figure 70. When a page is selected,  
multiple read backs from the same page can be done.  
Register Address[11:0]  
Register Data[7:0] = XX  
1
0
0
0
SDIN  
SCLK  
R/W  
M
P
CH  
A11  
A10  
A9  
A8  
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
SEN  
RESET  
SDOUT  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
SDOUT[7:0]  
Figure 70. Serial Register Read Timing Diagram  
8.4.1.4 JESD Bank SPI Page Selection  
The JESD SPI bank contains three pages (main digital, JESD digital, and JESD analog pages). The individual  
pages can be selected by:  
1. Driving the SEN pin low.  
2. Setting the M bit to 1 and specifying the page with two register writes. Note that the P bit must be set to 0, as  
shown in Figure 71.  
Write address 4003h with 00h (LSB byte of the page address).  
Write address 4004h with the MSB byte of the page address.  
For the main digital page: write address 4004h with 68h.  
For the JESD digital page: write address 4004h with 69h.  
For the JESD analog page: write address 4004h with 6Ah.  
Register Address[11:0]  
Register Data[7:0]  
D5 D4 D3 D2  
0
1
0
0
SDIN  
R/W  
M
P
CH A11 A10 A9  
A8  
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
D7  
D6  
D1  
D0  
SCLK  
SEN  
RESET  
Figure 71. SPI Page Selection  
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8.4.1.5 Serial Register Write: JESD Bank  
The ADS54J20 is a dual-channel device and the JESD204B portion is configured individually for each channel by  
using the CH bit. Note that the P bit must be set to 1 for register writes.  
1. Drive the SEN pin low.  
2. Select the JESD bank page. Note that the M bit = 1 and the P bit = 0.  
Write address 4003h with 00h.  
Write address 4005h with 01h to enable separate control for both channels.  
For the main digital page: write address 4004h with 68h.  
For the JESD digital page: write address 4004h with 69h.  
For the JESD analog page: write address 4004h with 6Ah.  
3. Set the M and P bits to 1, select channel A (CH = 0) or channel B (CH = 1), and write the register content as  
shown in Figure 72. When a page is selected, multiple writes into the same page can be done.  
Register Address[11:0]  
Register Data[7:0]  
0
1
1
0
SDIN  
SCLK  
R/W  
M
P
CH A11 A10  
A9  
A8  
A7 A6 A5 A4  
A3  
A2  
A1  
A0  
D7  
D6  
D5 D4 D3 D2  
D1  
D0  
SEN  
RESET  
Figure 72. JESD Serial Register Write Timing Diagram  
8.4.1.5.1 Individual Channel Programming  
By default, register writes are applied to both channels. To enable individual channel writes, write address 4005h  
with 01h (default is 00h).  
8.4.1.6 Serial Register Readout: JESD Bank  
The content from one of the pages of the JESD bank can be read out by:  
1. Driving the SEN pin low.  
2. Selecting the JESD bank page. Note that the M bit = 1 and the P bit = 0.  
Write address 4003h with 00h.  
Write address 4005h with 01h to enable separate control for both channels.  
For the main digital page: write address 4004h with 68h.  
For the JESD digital page: write address 4004h with 69h.  
For the JESD analog page: write address 4004h with 6Ah.  
3. Setting the R/W, M, and P bits to 1, selecting channel A or channel B, and writing the address to be read  
back.  
4. Reading back the register content on the SDOUT pin; see Figure 73. When a page is selected, multiple read  
backs from the same page can be done.  
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Register Address[11:0]  
A7 A6 A5 A4  
Register Data[7:0] = XX  
1
1
1
0
SDIN  
SCLK  
R/W  
M
P
CH A11 A10 A9  
A8  
A3  
A2  
A1  
A0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
SEN  
RESET  
SDOUT  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
SDOUT[7:0]  
Figure 73. JESD Serial Register Read Timing Diagram  
8.4.2 JESD204B Interface  
The ADS54J20 supports device subclass 1 with a maximum output data rate of 6.25 Gbps for each serial  
transmitter.  
An external SYSREF signal is used to align all internal clock phases and the local multiframe clock to a specific  
sampling clock edge, allowing synchronization of multiple devices in a system and minimizing timing and  
alignment uncertainty. The SYNC input is used to control the JESD204B SerDes blocks.  
Depending on the ADC output data rate, the JESD204B output interface can be operated with either two or four  
lanes per single ADC, as shown in Figure 74. The JESD204B setup and configuration of the frame assembly  
parameters is controlled via the SPI interface.  
SYSREF  
SYNC  
JESD204B  
DA[3:0]  
INA  
INB  
JESD204B  
JESD204B  
JESD204B  
DB[3:0]  
Sample Clock  
Figure 74. ADS54J20 Block Diagram  
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The JESD204B transmitter block shown in Figure 75 consists of the transport layer, the data scrambler, and the  
link layer. The transport layer maps the ADC output data into the selected JESD204B frame data format. The link  
layer performs the 8b, 10b data encoding as well as the synchronization and initial lane alignment using the  
SYNC input signal. Optionally, data from the transport layer can be scrambled.  
JESD204B Block  
Transport Layer  
Link Layer  
8b, 10b  
Encoding  
Frame Data  
Mapping  
Scrambler  
1 + x14 + x15  
D[3:0]  
Comma Characters,  
Initial Lane Alignment  
SYNC  
Figure 75. JESD204B Transmitter Block  
8.4.2.1 JESD204B Initial Lane Alignment (ILA)  
The initial lane alignment process is started when the receiving device deasserts the SYNC signal, as shown in  
Figure 76. When a logic low is detected on the SYNC input pin, the ADS54J20 starts transmitting comma (K28.5)  
characters to establish a code group synchronization.  
When synchronization is complete, the receiving device asserts the SYNC signal and the ADS54J20 starts the  
initial lane alignment sequence with the next local multiframe clock boundary. The ADS54J20 transmits four  
multiframes, each containing K frames (K is SPI programmable). Each of the multiframes contains the frame start  
and end symbols and the second multiframe also contains the JESD204 link configuration data.  
SYSREF  
LMFC Clock  
LMFC Boundary  
Multi  
Frame  
SYNC  
Transmit Data  
xxx  
K28.5  
Code Group  
K28.5  
Initial Lane  
ILA  
ILA  
DATA  
DATA  
Data Transmission  
Synchronization  
Alignment  
Figure 76. Lane Alignment Sequence  
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8.4.2.2 JESD204B Test Patterns  
There are three different test patterns available in the transport layer of the JESD204B interface. The ADS54J20  
supports a clock output, encoded, and a PRBS (215 – 1) pattern. These test patterns can be enabled via an SPI  
register write and are located in the JESD digital page of the JESD bank.  
8.4.2.3 JESD204B Frame  
The JESD204B standard defines the following parameters:  
L is the number of lanes per link.  
M is the number of converters per device.  
F is the number of octets per frame clock period, per lane.  
S is the number of samples per frame per converter.  
8.4.2.4 JESD204B Frame  
Table 10 lists the available JESD204B formats and valid ranges for the ADS54J20 when the decimation filter is  
not used. The ranges are limited by the SerDes lane rate and the maximum ADC sample frequency.  
NOTE  
The 16-bit data going to the JESD 8b, 10b encoder are formed by padding four 0s as  
LSBs into the 12-bit ADC data.  
Table 10. Default Interface Rates  
MINIMUM RATES  
MAXIMUM RATES  
L
M
F
S
DECIMATION  
SAMPLING  
RATE (MSPS)  
SERDES BIT  
RATE (Gbps)  
SAMPLING  
RATE (MSPS)  
SERDES BIT  
RATE (Gbps)  
4
4
8
2
2
2
1
4
2
1
4
4
Not used  
Not used  
Not used  
250  
250  
500  
2.5  
2.5  
2.5  
1000  
10.0  
10.0  
5.0  
1000  
1000  
NOTE  
In the LMFS = 8224 row of Table 11, the sample order on the lanes is DA2, DA3, DA1,  
and DA0 for channel A. Similarly for channel B, the sample order on the lanes is DB2,  
DB3, DB1, and DB0.  
The detailed frame assembly is shown in Table 11.  
Table 11. Default Frame Assembly(1)  
OUTPUT  
LANE  
LMFS = 4211  
LMFS = 4244  
LMFS = 8224  
A3[11:4]  
DA0  
DA1  
DA2  
DA3  
DB0  
DB1  
DB2  
DB3  
A3[3:0], 0000  
A2[3:0], 0000  
A0[3:0], 0000  
A1[3:0], 0000  
B3[3:0], 0000  
B2[3:0], 0000  
B0[3:0], 0000  
B1[3:0], 0000  
A0[3:0], 0000  
A0[11:4]  
A2[11:4]  
A0[11:4]  
A2[3:0], 0000  
A3[11:4]  
A1[11:4]  
A3[3:0], 0000  
A1[3:0], 0000  
A2[11:4]  
A0[11:4]  
A1[11:4]  
B3[11:4]  
B2[11:4]  
B0[11:4]  
B1[11:4]  
A0[3:0], 0000  
B0[3:0], 0000  
B0[11:4]  
B2[11:4]  
B0[11:4]  
B2[3:0], 0000  
B0[3:0], 0000  
B3[11:4]  
B1[11:4]  
B3[3:0], 0000  
B1[3:0], 0000  
(1) Blue shading indicates channel A and yellow shading indicates channel B.  
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8.4.2.5 JESD204B Frame Assembly with Decimation  
Table 12 lists the available JESD204B formats and valid ranges for the ADS54J20 when enabling the decimation  
filter. The ranges are limited by the SerDes lane rate (2.5 Gbps to 10.0 Gbps) and the ADC sample frequency  
(300 MSPS to 1000 MSPS).  
Table 12. Interface Rates with Decimation Filter  
MINIMUM RATES  
MAXIMUM RATES  
DEVICE  
CLOCK  
FREQUENCY  
(MSPS)  
DEVICE  
CLOCK  
FREQUENCY  
(MSPS)  
OUTPUT  
SAMPLE  
RATE (MSPS)  
OUTPUT  
SAMPLE  
RATE (MSPS)  
L
M
F
S
DECIMATION  
SERDES BIT  
RATE (Gbps)  
SERDES BIT  
RATE (Gbps)  
4
4
2
2
2
1
4
2
2
2
4
2
2
2
4
2
4
4
1
2
2
1
1
1
4X (IQ)  
2X  
500  
500  
300  
500  
300  
300  
125  
250  
150  
125  
75  
2.5  
2.5  
3
1000  
1000  
1000  
1000  
1000  
1000  
250  
500  
500  
250  
250  
250  
5
5
2X  
10  
5
4X  
2.5  
3
4X (IQ)  
4X  
10  
10  
75  
3
Table 13 lists the detailed frame assembly with different decimation options.  
Table 13. Frame Assembly with Decimation Filter(1)  
OUTPUT  
LANE  
LMFS = 4222, 2X  
DECIMATION  
LMFS = 2242,  
2X DECIMATION  
LMFS = 2221, 4X  
DECIMATION  
LMFS = 2441,  
4X DECIMATION (IQ)  
LMFS = 4421, 4X  
DECIMATION (IQ)  
LMFS = 1241,  
4X DECIMATION  
A1  
AQ0  
AQ0  
A1  
DA0  
DA1  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
A0  
A0  
A1  
[3:0],  
0000  
A0  
AI0  
AQ0  
[3:0],  
0000  
AI0  
AI0  
A0  
B0  
[3:0],  
0000  
A0  
A0  
[11:4]  
A1  
A0  
AI0  
[11:4]  
AQ0  
A0  
[11:4]  
B0  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
[3:0],  
[3:0],  
[11:4]  
0000  
[11:4]  
0000  
DA2  
DA3  
B1  
BQ0  
BQ0  
B1  
DB0  
DB1  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
B0  
B0  
B1  
[3:0],  
0000  
B0  
BI0  
BQ0  
[3:0],  
0000  
BI0  
BI0  
B0  
B0  
[11:4]  
B1  
B0  
BI0  
[11:4]  
BQ0  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
[3:0],  
[11:4]  
0000  
DB2  
DB3  
(1) Blue shading indicates channel A and yellow shading indicates channel B.  
40  
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Appropriate register bits must be programmed to enable different options when the decimation filter is enabled. Table 14 summarizes all the decimation  
filter options available in the DDC block, the corresponding JESD link parameters (L, M, F, and S), and the register bits required to be programmed for  
each option.  
Table 14. Program Summary of DDC Modes and JESD Link Configuration(1)(2)  
LMFS OPTIONS  
DDC MODES PROGRAMMING  
JESD LINK (LMFS) PROGRAMMING  
DECIMATION  
OPTIONS  
DEC MODE EN,  
JESD PLL  
MODE(7)  
DA_BUS_  
DB_BUS_  
BUS_REORDER BUS_REORDER  
L
M
F
S
DECFIL MODE[3:0](4)  
JESD FILTER(5)  
JESD MODE(6)  
LANE SHARE(8)  
DECFIL EN(3)  
REORDER(9)  
REORDER(10)  
EN1(11)  
EN2(12)  
4
4
2
2
1
4
1
4
No decimation  
No decimation  
00  
00  
00  
00  
000  
000  
100  
010  
10  
10  
0
0
00h  
00h  
00h  
00h  
0
0
0
0
No decimation  
(Default after  
reset)  
8
2
2
4
00  
00  
000  
001  
00  
0
00h  
00h  
0
0
4
4
2
4
2
2
2
2
4
1
2
2
4X (IQ)  
2X  
11  
11  
11  
0011 (LPF with fS / 4 mixer)  
0010 (LPF) or 0110 (HPF)  
0010 (LPF) or 0110 (HPF)  
111  
110  
110  
001  
001  
010  
00  
00  
10  
0
0
0
0Ah  
0Ah  
0Ah  
0Ah  
0Ah  
0Ah  
1
1
1
1
1
1
2X  
0000, 0100, 1000, or 1100  
(all BPFs with different  
center frequencies).  
2
2
1
2
4
2
2
4
4
1
1
1
4X  
4X (IQ)  
4X  
11  
11  
11  
100  
111  
100  
001  
010  
010  
00  
10  
10  
0
0
1
0Ah  
0Ah  
0Ah  
0Ah  
0Ah  
0Ah  
1
1
1
1
1
1
0011 (LPF with an fS / 4  
mixer)  
0000, 0100, 1000, or 1100  
(all BPFs with different  
center frequencies)  
(1) Keeping the same LMFS settings for both channels is recommended.  
(2) The PULSE RESET register bit must be pulsed after the registers in the main digital page are programmed.  
(3) The DEC MODE EN and DECFIL EN register bits are located in the main digital page, register 04Dh (bit 3) and register 041h (bit 4).  
(4) The DECFIL MODE[3:0] register bits are located in the main digital page, register 041h (bits 5 and 2-0).  
(5) The JESD FILTER register bits are located in the JESD digital page, register 001h (bits 5-3).  
(6) The JESD MODE register bits are located in the JESD digital page, register 001h (bits 2-0).  
(7) The JESD PLL MODE register bits are located in the JESD analog page, register 016h (bits 1-0).  
(8) The LANE SHARE register bit is located in the JESD digital page, register 016h (bit 4).  
(9) The DA_BUS_REORDER register bits are located in the JESD digital page, register 031h (bits 7-0).  
(10) The DB_BUS_REORDER register bits are located in the JESD digital page, register 032h (bits 7-0).  
(11) The BUS_REORDER EN1 register bit is located in the main digital page, register 052h (bit 7).  
(12) The BUS_REORDER EN2 register bit is located in the main digital page, register 072h (bit 3).  
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8.4.2.5.1 JESD Transmitter Interface  
Each of the 6.25-Gbps SerDes JESD transmitter outputs require ac-coupling between the transmitter and  
receiver. The differential pair must be terminated with 100-Ω resistors as close to the receiving device as  
possible to avoid unwanted reflections and signal degradation, as shown in Figure 77.  
0.1 mF  
DA[3:0]P,  
DB[3:0]P  
Rt = ZO  
Transmission Line, Zo  
VCM  
Receiver  
Rt = ZO  
DA[3:0]M,  
DB[3:0]M  
0.1 mF  
Figure 77. Output Connection to Receiver  
42  
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8.4.2.5.2 Eye Diagrams  
Figure 78 to Figure 81 show the serial output eye diagrams of the ADS54J20 at 5.0 Gbps and 10 Gbps with  
default and increased output voltage swing against the JESD204B mask.  
Figure 79. Eye Diagram at 5-Gbps Bit Rate with  
Increased Output Swing  
Figure 78. Eye Diagram at 5-Gbps Bit Rate with  
Default Output Swing  
Figure 81. Eye Diagram at 10-Gbps Bit Rate with  
Increased Output Swing  
Figure 80. Eye Diagram at 10-Gbps Bit Rate with  
Default Output Swing  
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8.5 Register Maps  
Figure 82 shows a conceptual diagram of the serial registers.  
Initiate an SPI Cycle  
R/W, M, P, CH, Bits Decoder  
M = 0  
M = 1  
Analog Bank  
JESD Bank  
General Register  
General Register  
(Address 005h,  
Keep M = 1, P = 0)  
JESD Bank Page Selection  
(Address 003h and Address 004h,  
Keep M = 1, P = 0)  
Unused Registers  
(Address 01h, Address 02h.  
Keep M = 1, P = 0)  
Analog Bank Page Selection  
(Address 00h,  
(Address 011h, Keep M = 0, P = 0)  
Keep M = 0, P = 0)  
Value 80h  
Addr 5Fh  
Value 0Fh  
Value 6800h  
Value 6900h  
Value 6A00h  
Addr 0h  
Addr 20h  
Addr 0h  
Addr 12h  
Main  
Digital Page  
JESD  
ADC Page  
(Fast OVR)  
JESD  
Digital Page  
Master Page  
(PDN, OVR,  
DC Coupling)  
Analog Page  
(PLL Configuration,  
Output Swing,  
(Nyquist Zone,  
Gain,  
OVR, Filter)  
Keep  
M = 0, P = 0  
(JESD  
Configuration)  
Pre-Emphasis)  
Keep  
M = 0, P = 0  
Keep M = 1,  
P = 1  
Keep M = 1,  
P = 1  
Keep M = 1,  
P = 1  
Addr F7h  
Addr 59h  
Addr 32h  
Addr 1Bh  
Figure 82. Serial Interface Registers  
44  
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8.5.1 Detailed Register Information  
The ADS54J20 contains two main SPI banks. The analog SPI bank provides access to the ADC analog blocks  
and the digital SPI bank controls the interleaving engine and anything related to the JESD204B serial interface.  
The analog SPI bank is divided into two pages (master and ADC) and the digital SPI bank is divided into three  
pages (main digital, JESD digital, and JESD analog). Table 15 lists a register map for the ADS54J20.  
Table 15. Register Map  
REGISTER  
ADDRESS  
REGISTER DATA  
A[11:0] (Hex)  
7
6
5
4
3
2
1
0
GENERAL REGISTERS  
0
3
4
RESET  
0
0
0
0
0
0
RESET  
JESD BANK PAGE SEL[7:0]  
JESD BANK PAGE SEL[15:8]  
DISABLE  
BROADCAST  
5
0
0
0
0
0
0
0
11  
ANALOG BANK PAGE SEL  
MASTER PAGE (80h)  
20  
21  
23  
24  
PDN ADC CHA  
PDN ADC CHA  
PDN ADC CHB  
PDN ADC CHB  
PDN BUFFER CHB  
PDN BUFFER CHB  
PDN BUFFER CHA  
PDN BUFFER CHA  
0
0
0
0
0
0
0
0
0
0
0
0
OVERRIDE  
PDN MASK  
26  
4F  
53  
GLOBAL PDN  
0
0
0
PDN PIN  
SEL  
EN INPUT DC  
COUPLING  
0
0
0
0
0
0
0
0
0
EN SYSREF  
DC COUPLING  
MASK SYSREF  
0
0
SET SYSREF  
0
ENABLE  
MANUAL  
SYSREF  
54  
0
0
0
0
0
0
55  
59  
0
0
0
PDN MASK  
0
0
0
0
0
0
0
0
0
ALWAYS  
WRITE 1  
FOVR CHB  
ADC PAGE (0Fh)  
5F  
FOVR THRESHOLD PROG  
MAIN DIGITAL PAGE (6800h)  
0
0
0
0
0
0
0
0
0
0
0
0
PULSE RESET  
FORMAT SEL  
DECFIL  
MODE[3]  
41  
DECFIL EN  
DECFIL MODE[2:0]  
42  
43  
44  
4B  
4D  
0
0
0
0
0
0
0
0
0
0
0
0
NYQUIST ZONE  
0
0
DIGITAL GAIN  
0
0
0
FORMAT EN  
0
0
0
0
0
0
0
0
0
DEC MODE EN  
CTRL  
NYQUIST  
4E  
52  
0
0
0
0
0
0
0
0
0
0
0
0
0
BUS_  
REORDER  
EN1  
DIG GAIN EN  
BUS_  
REORDER  
EN2  
72  
0
0
0
0
0
0
0
0
AB  
AD  
F7  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
LSB SEL EN  
LSB SELECT  
DIG RESET  
0
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Table 15. Register Map (continued)  
REGISTER  
ADDRESS  
REGISTER DATA  
A[11:0] (Hex)  
7
6
5
4
3
2
1
0
JESD DIGITAL PAGE (6900h)  
TESTMODE  
EN  
FLIP ADC  
DATA  
0
1
2
CTRL K  
0
0
LANE ALIGN  
FRAME ALIGN  
JESD MODE  
0
TX LINK DIS  
SYNC REG  
SYNC REG EN  
JESD FILTER  
LINK LAYER  
RPAT  
LMFC MASK  
RESET  
LINK LAYER TESTMODE  
0
0
FORCE LMFC  
3
5
LMFC COUNT INIT  
0
RELEASE ILANE SEQ  
COUNT  
SCRAMBLE  
EN  
0
0
0
0
0
0
6
0
0
1
0
0
0
0
0
0
FRAMES PER MULTI FRAME (K)  
7
0
SUBCLASS  
0
0
0
0
0
0
16  
31  
32  
LANE SHARE  
0
DA_BUS_REORDER[7:0]  
DB_BUS_REORDER[7:0]  
JESD ANALOG PAGE (6A00h)  
12  
13  
14  
15  
SEL EMP LANE 1  
0
0
0
0
0
0
0
0
SEL EMP LANE 0  
SEL EMP LANE 2  
SEL EMP LANE 3  
16  
17  
1A  
1B  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JESD PLL MODE  
PLL RESET  
0
0
0
0
0
0
0
0
0
FOVR CHA  
0
JESD SWING  
FOVR CHA EN  
46  
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8.5.2 Example Register Writes  
This section provides three different example register writes. Table 16 describes a global power-down register  
write, Table 17 describes the register writes when the default lane setting (eight active lanes per device) is  
changed to four active lanes (LMFS = 4211), and Table 18 describes the register writes for 2X decimation with  
four active lanes (LMFS = 4222).  
Table 16. Global Power Down  
ADDRESS (Hex)  
0-011h  
DATA (Hex)  
80h  
COMMENT  
Set the master page  
0-026h  
C0h  
Set the global power-down  
Table 17. Two Lanes per Channel Mode (LMFS = 4211)  
ADDRESS (Hex)  
4-004h  
DATA (Hex)  
69h  
COMMENT  
Select the JESD digital page  
Select the JESD digital page  
Select the digital to 40X mode  
Select the JESD analog page  
Set the SerDes PLL to 40X mode  
4-003h  
00h  
6-001h  
02h  
4-004h  
6Ah  
6-016h  
02h  
Table 18. 2X Decimation (LPF for Both Channels) with Four Active Lanes (LMFS = 4222)  
ADDRESS (Hex)  
4-004h  
DATA (Hex)  
68h  
COMMENT  
Select the main digital page (6800h)  
Select the main digital page (6800h)  
Set decimate-by-2 (low-pass filter)  
Enable decimation filter control  
BUS_REORDER EN2  
4-003h  
00h  
6-041h  
12h  
6-04Dh  
6-072h  
08h  
08h  
6-052h  
80h  
BUS_REORDER EN1  
6-000h  
01h  
Pulse the PULSE RESET bit (so that register writes to the main digital page go into effect).  
6-000h  
00h  
4-004h  
69h  
Select the JESD digital page (6900h)  
4-003h  
00h  
Select the JESD digital page (6900h)  
6-031h  
0Ah  
Output bus reorder for channel A  
6-032h  
0Ah  
Output bus reorder for channel B  
6-001h  
31h  
Program the JESD MODE and JESD FILTER register bits for LMFS = 4222.  
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8.5.3 Register Descriptions  
8.5.3.1 General Registers  
8.5.3.1.1 Register 0h (address = 0h)  
Figure 83. Register 0h  
7
6
0
5
0
4
0
3
0
2
0
1
0
0
RESET  
W-0h  
RESET  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: W = Write only; -n = value after reset  
Table 19. Register 0h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
RESET  
W
0h  
0 = Normal operation  
1 = Internal software reset, clears back to 0  
6-1  
0
0
W
W
0h  
0h  
Must write 0  
RESET  
0 = Normal operation  
1 = Internal software reset, clears back to 0  
8.5.3.1.2 Register 3h (address = 3h)  
Figure 84. Register 3h  
7
6
5
4
3
2
1
0
JESD BANK PAGE SEL[7:0]  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 20. Register 3h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-0  
JESD BANK PAGE SEL[7:0]  
R/W  
0h  
Program these bits to access the desired page in the JESD bank.  
6800h = Main digital page selected  
6900h = JESD digital page selected  
6A00h = JESD analog page selected  
8.5.3.1.3 Register 4h (address = 4h)  
Figure 85. Register 4h  
7
6
5
4
3
2
1
0
JESD BANK PAGE SEL[15:8]  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 21. Register 4h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-0  
JESD BANK PAGE SEL[15:8]  
R/W  
0h  
Program these bits to access the desired page in the JESD bank.  
6800h = Main digital page selected  
6900h = JESD digital page selected  
6A00h = JESD analog page selected  
48  
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8.5.3.1.4 Register 5h (address = 5h)  
Figure 86. Register 5h  
7
0
6
0
5
0
4
3
0
2
1
0
0
0
0
DISABLE BROADCAST  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 22. Register 5h Field Descriptions  
Bit  
7-1  
0
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
DISABLE BROADCAST  
R/W  
0h  
0 = Normal operation; channel A and B are programmed as a pair  
1 = Channel A and B can be individually programmed based on the  
CH bit  
8.5.3.1.5 Register 11h (address = 11h)  
Figure 87. Register 11h  
7
6
5
4
3
2
1
0
ANALOG PAGE SELECTION  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 23. Register 11h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-0  
ANALOG BANK PAGE SEL  
R/W  
0h  
Program these bits to access the desired page in the analog bank.  
Master page = 80h  
ADC page = 0Fh  
8.5.3.2 Master Page (080h) Registers  
8.5.3.2.1 Register 20h (address = 20h), Master Page (080h)  
Figure 88. Register 20h  
7
6
5
4
3
2
1
0
PDN ADC CHA  
R/W-0h  
PDN ADC CHB  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 24. Registers 20h Field Descriptions  
Bit  
7-4  
3-0  
Field  
Type  
R/W  
R/W  
Reset  
0h  
Description  
PDN ADC CHA  
PDN ADC CHB  
There are two power-down masks that are controlled via the  
PDN mask register bit in address 55h. The power-down mask 1  
or mask 2 are selected via register bit 5 in address 26h.  
Power-down mask 1: addresses 20h and 21h.  
Power-down mask 2: addresses 23h and 24h.  
0Fh = Power-down CHB only.  
0h  
F0h = Power-down CHA only.  
FFh = Power-down both.  
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8.5.3.2.2 Register 21h (address = 21h), Master Page (080h)  
Figure 89. Register 21h  
7
6
5
4
3
0
2
0
1
0
0
0
PDN BUFFER CHB  
R/W-0h  
PDN BUFFER CHA  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 25. Register 21h Field Descriptions  
Bit  
7-6  
5-4  
Field  
Type  
R/W  
R/W  
Reset  
0h  
Description  
PDN BUFFER CHB  
PDN BUFFER CHA  
There are two power-down masks that are controlled via the  
PDN mask register bit in address 55h. The power-down mask 1  
or mask 2 are selected via register address 26h, bit 5.  
Power-down mask 1: addresses 20h and 21h.  
Power-down mask 2: addresses 23h and 24h.  
There are two buffers per channel. One buffer drives two ADC  
cores.  
0h  
PDN BUFFER CHx:  
00 = Both buffers of a channel are active.  
11 = Both buffers are powered down.  
01–10 = Do not use.  
3-0  
0
W
0h  
Must write 0.  
8.5.3.2.3 Register 23h (address = 23h), Master Page (080h)  
Figure 90. Register 23h  
7
6
5
4
3
2
1
0
PDN ADC CHA  
R/W-0h  
PDN ADC CHB  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 26. Register 23h Field Descriptions  
Bit  
7-4  
3-0  
Field  
Type  
R/W  
R/W  
Reset  
0h  
Description  
PDN ADC CHA  
PDN ADC CHB  
There are two power-down masks that are controlled via the  
PDN mask register bit in address 55h. The power-down mask 1  
or mask 2 are selected via register address 26h, bit 5.  
Power-down mask 1: addresses 20h and 21h.  
Power-down mask 2: addresses 23h and 24h.  
0Fh = Power-down CHB only.  
0h  
F0h = Power-down CHA only.  
FFh = Power-down both.  
50  
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8.5.3.2.4 Register 24h (address = 24h), Master Page (080h)  
Figure 91. Register 24h  
7
6
5
4
3
0
2
0
1
0
0
0
PDN BUFFER CHB  
R/W-0h  
PDN BUFFER CHA  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 27. Register 24h Field Descriptions  
Bit  
7-6  
5-4  
Field  
Type  
R/W  
R/W  
Reset  
0h  
Description  
PDN BUFFER CHB  
PDN BUFFER CHA  
There are two power-down masks that are controlled via the  
PDN mask register bit in address 55h. The power-down mask 1  
or mask 2 are selected via register address 26h, bit 5.  
Power-down mask 1: addresses 20h and 21h.  
Power-down mask 2: addresses 23h and 24h.  
Power-down mask 2: addresses 23h and 24h.  
There are two buffers per channel. One buffer drives two ADC  
cores.  
0h  
PDN BUFFER CHx:  
00 = Both buffers of a channel are active.  
11 = Both buffers are powered down.  
01–10 = Do not use.  
3-0  
0
W
0h  
Must write 0.  
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8.5.3.2.5 Register 26h (address = 26h), Master Page (080h)  
Figure 92. Register 26h  
7
6
5
4
0
3
0
2
0
1
0
0
0
OVERRIDE  
PDN PIN  
PDN MASK  
SEL  
GLOBAL PDN  
R/W-0h  
R/W-0h  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 28. Register 26h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
GLOBAL PDN  
R/W  
0h  
Bit 6 (OVERRIDE PDN PIN) must be set before this bit can be  
programmed.  
0 = Normal operation  
1 = Global power-down via the SPI  
6
5
OVERRIDE PDN PIN  
R/W  
R/W  
W
0h  
0h  
0h  
This bit ignores the power-down pin control.  
0 = Normal operation  
1 = Ignores inputs on the power-down pin  
PDN MASK SEL  
0
This bit selects power-down mask 1 or mask 2.  
0 = Power-down mask 1  
1 = Power-down mask 2  
4-0  
Must write 0  
8.5.3.2.6 Register 4Fh (address = 4Fh), Master Page (080h)  
Figure 93. Register 4Fh  
7
0
6
0
5
0
4
3
2
1
0
0
0
0
0
EN INPUT DC COUPLING  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 29. Register 4Fh Field Descriptions  
Bit  
7-1  
0
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
EN INPUT DC COUPLING  
R/W  
0h  
This bit enables dc-coupling between the analog inputs and the  
driver by changing the internal biasing resistor between the  
analog inputs and VCM from 600 Ω to 5 kΩ.  
0 = The dc-coupling support is disabled  
1 = The dc-coupling support is enabled  
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8.5.3.2.7 Register 53h (address = 53h), Master Page (080h)  
Figure 94. Register 53h  
7
0
6
5
0
4
0
3
0
2
0
1
0
MASK  
SYSREF  
EN SYSREF  
DC COUPLING  
SET SYSREF  
R/W-0h  
W-0h  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 30. Register 53h Field Descriptions  
Bit  
7
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
6
MASK SYSREF  
R/W  
0h  
0 = Normal operation  
1 = Ignores the SYSREF input  
5-2  
1
0
W
0h  
0h  
Must write 0  
EN SYSREF DC COUPLING  
R/W  
This bit enables a higher common-mode voltage input on the  
SYSREF signal (up to 1.6 V).  
0 = Normal operation  
1 = Enables a higher SYSREF common-mode voltage support  
0
SET SYSREF  
R/W  
0h  
0 = Set SYSREF low  
1 = Set SYSREF high  
8.5.3.2.8 Register 54h (address = 54h), Master Page (080h)  
Figure 95. Register 54h  
7
6
0
5
0
4
3
2
0
1
0
0
0
ENABLE  
MANUAL  
SYSREF  
0
0
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 31. Register 54h Field Descriptions  
Bit  
7
Field  
Type  
R/W  
W
Reset  
0h  
Description  
ENABLE MANUAL SYSREF  
0
This bit enables manual SYSREF  
Must write 0  
6-0  
0h  
8.5.3.2.9 Register 55h (address = 55h), Master Page (080h)  
Figure 96. Register 55h  
7
0
6
0
5
0
4
3
2
0
1
0
0
0
PDN MASK  
R/W-0h  
0
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 32. Register 55h Field Descriptions  
Bit  
7-5  
4
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
PDN MASK  
R/W  
0h  
This bit enables power-down via a register bit.  
0 = Normal operation  
1 = Power-down is enabled by powering down the internal  
blocks as specified in the selected power-down mask  
3-0  
0
W
0h  
Must write 0  
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8.5.3.2.10 Register 59h (address = 59h), Master Page (080h)  
Figure 97. Register 59h  
7
6
0
5
4
0
3
0
2
0
1
0
0
0
FOVR CHB  
W-0h  
ALWAYS WRITE 1  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 33. Register 59h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
FOVR CHB  
W
0h  
This bit outputs the FOVR signal for channel B on the SDOUT pin.  
0 = Normal operation  
1 = The FOVR signal is available on the SDOUT pin  
6
5
0
W
0h  
0h  
0h  
Must write 0  
Must write 1  
Must write 0  
ALWAYS WRITE 1  
0
R/W  
W
4-0  
8.5.3.3 ADC Page (0Fh) Register  
8.5.3.3.1 Register 5F (addresses = 5F), ADC Page (0Fh)  
Figure 98. Register 5F  
7
6
5
4
3
2
1
0
FOVR THRESHOLD PROG  
R/W-E3h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 34. Register 5F Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-0  
FOVR THRESHOLD PROG  
R/W  
E3h  
Program the fast OVR thresholds together for channel A and B,  
as described in the Overrange Indication section.  
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8.5.3.4 Main Digital Page (6800h) Registers  
8.5.3.4.1 Register 0h (address = 0h), Main Digital Page (6800h)  
Figure 99. Register 0h  
7
0
6
0
5
0
4
3
2
0
1
0
0
0
0
PULSE RESET  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 35. Register 0h Field Descriptions  
Bit  
7-1  
0
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
PULSE RESET  
R/W  
0h  
This bit must be pulsed after power-up or after configuring  
registers in the main digital page of the JESD bank. Any register  
bits in the main digital page (6800h) take effect only after this bit  
is pulsed; see the Start-Up Sequence section for the correct  
sequence.  
0 = Normal operation  
0 1 0 = This bit is pulsed  
8.5.3.4.2 Register 41h (address = 41h), Main Digital Page (6800h)  
Figure 100. Register 41h  
7
0
6
0
5
4
3
2
1
0
DECFIL MODE[3]  
R/W-0h  
DECFIL EN  
R/W-0h  
0
DECFIL MODE[2:0]  
R/W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 36. Register 41h Field Descriptions  
Bit  
7-6  
5
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
DECFIL MODE[3]  
R/W  
0h  
This bit selects the decimation filter mode. Table 37 lists the bit settings.  
The decimation filter control (DEC MODE EN, register 4Dh, bit 3) and  
decimation filter enable (DECFIL EN, register 41h, bit 4) must be enabled.  
4
DECFIL EN  
R/W  
0h  
This bit enables the digital decimation filter.  
0 = Normal operation, full rate output  
1 = Digital decimation enabled  
3
0
W
0h  
0h  
Must write 0  
2-0  
DECFIL MODE[2:0]  
R/W  
These bits select the decimation filter mode. Table 37 lists the bit settings.  
The decimation filter control (DEC MODE EN, register 4Dh, bit 3) and  
decimation filter enable (DECFIL EN, register 41h, bit 4) must be enabled.  
Table 37. DECFIL MODE Bit Settings  
BITS (5, 2-0)  
FILTER MODE  
DECIMATION  
0000  
0100  
1000  
1100  
0010  
0110  
0011  
Band-pass filter centered on 3 × fS / 16  
Band-pass filter centered on 5 × fS / 16  
4X  
4X  
Band-pass filter centered on 1 × fS / 16  
Band-pass filter centered on 7 × fS / 16  
Low-pass filter  
4X  
4X  
2X  
High-pass filter  
2X  
Low-pass filter with fS / 4 mixer  
4X (IQ)  
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8.5.3.4.3 Register 42h (address = 42h), Main Digital Page (6800h)  
Figure 101. Register 42h  
7
0
6
0
5
0
4
0
3
0
2
1
0
NYQUIST ZONE  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 38. Register 42h Field Descriptions  
Bit  
7-3  
2-0  
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
NYQUIST ZONE  
R/W  
0h  
The Nyquist zone must be selected for proper interleaving  
correction. Nyquist refers to the device clock / 2. For a 1.0-  
GSPS device clock, the Nyquist frequency is 500 MHz. The  
CTRL NYQUIST register bit (register 4Eh, bit 7) must also be  
set.  
000 = First Nyquist zone (0 MHz to 500 MHz)  
001 = Second Nyquist zone (500 MHz to 1000 MHz)  
010 = Third Nyquist zone (1000 MHz to 1500 MHz)  
All others = Not used  
8.5.3.4.4 Register 43h (address = 43h), Main Digital Page (6800h)  
Figure 102. Register 43h  
7
0
6
0
5
0
4
3
2
0
1
0
0
0
0
FORMAT SEL  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 39. Register 43h Field Descriptions  
Bit  
7-1  
0
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
FORMAT SEL  
R/W  
0h  
This bit changes the output format. Set the FORMAT EN bit to  
enable control using this bit.  
0 = Twos complement  
1 = Offset binary  
8.5.3.4.5 Register 44h (address = 44h), Main Digital Page (6800h)  
Figure 103. Register 44h  
7
0
6
5
4
3
2
1
0
DIGITAL GAIN  
R/W-0h  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 40. Register 44h Field Descriptions  
Bit  
7
Field  
Type  
R/W  
R/W  
Reset  
0h  
Description  
0
Must write 0  
6-0  
DIGITAL GAIN  
0h  
These bits set the digital gain setting. The DIG GAIN EN register  
bit (register 52h, bit 0) must be enabled to use these bits.  
Gain in dB = 20log (digital gain / 32).  
7Fh = 127 equals a digital gain of 9.5 dB.  
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8.5.3.4.6 Register 4Bh (address = 4Bh), Main Digital Page (6800h)  
Figure 104. Register 4Bh  
7
0
6
0
5
4
0
3
0
2
0
1
0
0
0
FORMAT EN  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 41. Register 4Bh Field Descriptions  
Bit  
7-6  
5
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
FORMAT EN  
R/W  
0h  
This bit enables control for data format selection using the FORMAT  
SEL register bit.  
0 = Default, output is in twos complement format  
1 = Output is in offset binary format after the FORMAT SEL bit is set  
4-0  
0
W
0h  
Must write 0  
8.5.3.4.7 Register 4Dh (address = 4Dh), Main Digital Page (6800h)  
Figure 105. Register 4Dh  
7
0
6
0
5
0
4
0
3
2
0
1
0
0
0
DEC MOD EN  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 42. Register 4Dh Field Descriptions  
Bit  
7-4  
3
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
DEC MOD EN  
R/W  
0h  
This bit enables control of the decimation filter mode via the  
DECFIL MODE[3:0] register bits.  
0 = Default  
1 = Decimation mode control is enabled  
2-0  
0
W
0h  
Must write 0  
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8.5.3.4.8 Register 4Eh (address = 4Eh), Main Digital Page (6800h)  
Figure 106. Register 4Eh  
7
6
0
5
0
4
0
3
0
2
0
1
0
0
0
CTRL NYQUIST  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 43. Register 4Eh Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
CTRL NYQUIST  
R/W  
0h  
This bit enables selecting the Nyquist zone using register 42h, bits 2-0.  
0 = Selection disabled  
1 = Selection enabled  
6-0  
0
W
0h  
Must write 0  
8.5.3.4.9 Register 52h (address = 52h), Main Digital Page (6800h)  
Figure 107. Register 52h  
7
6
0
5
0
4
0
3
0
2
0
1
0
0
BUS_REORDER EN1  
W-0h  
DIG GAIN EN  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 44. Register 52h Field Descriptions  
Bit  
7
Field  
Type  
R/W  
W
Reset  
0h  
Description  
BUS_REORDER EN1  
Must write 1 in DDC mode only.  
Must write 0  
6-1  
0
0
0h  
DIG GAIN EN  
R/W  
0h  
This bit enables selecting the digital gain for register 44h.  
0 = Digital gain disabled  
1 = Digital gain enabled  
8.5.3.4.10 Register 72h (address = 72h), Main Digital Page (6800h)  
Figure 108. Register 72h  
7
0
6
0
5
0
4
0
3
2
0
1
0
0
0
BUS_REORDER EN2  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 45. Register 72h Field Descriptions  
Bit  
7-4  
3
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
BUS_REORDER EN2  
0
R/W  
W
0h  
Must write 1 in DDC mode only.  
Must write 0  
2-0  
0h  
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8.5.3.4.11 Register ABh (address = ABh), Main Digital Page (6800h)  
Figure 109. Register ABh  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
LSB SEL EN  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 46. Register ABh Field Descriptions  
Bit  
7-1  
0
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
LSB SEL EN  
R/W  
0h  
This bit enables control for the LSB SELECT register bit.  
0 = Default  
1 = LSB of the 16-bit data (12-bit ADC data padded with four 0s  
as the LSBs) can be programmed as fast OVR using the LSB  
SELECT register bit.  
8.5.3.4.12 Register ADh (address = ADh), Main Digital Page (6800h)  
Figure 110. Register ADh  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
LSB SELECT  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 47. Register ADh Field Descriptions  
Bit  
7-2  
1-0  
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
LSB SELECT  
R/W  
0h  
These bits enable the output of the FOVR flag instead of the output data  
LSB. Ensure that the LSB SEL EN register bit is set to 1.  
00 = Output is 16-bit data (12-bit ADC data padded with four 0s as the  
LSBs)  
11 = The LSB of the 16-bit output data is replaced by the FOVR  
information for each channel  
8.5.3.4.13 Register F7h (address = F7h), Main Digital Page (6800h)  
Figure 111. Register F7h  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
DIG RESET  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: W = Write only; -n = value after reset  
Table 48. Register F7h Field Descriptions  
Bit  
7-1  
0
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
DIG RESET  
W
0h  
This bit is the self-clearing reset for the digital block and does  
not include interleaving correction.  
0 = Normal operation  
1 = Digital reset  
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8.5.3.5 JESD Digital Page (6900h) Registers  
8.5.3.5.1 Register 0h (address = 0h), JESD Digital Page (6900h)  
Figure 112. Register 0h  
7
6
0
5
0
4
3
2
1
0
TESTMODE  
EN  
FLIP ADC  
DATA  
CTRL K  
R/W-0h  
LANE ALIGN  
R/W-0h  
FRAME ALIGN  
R/W-0h  
TX LINK DIS  
R/W-0h  
W-0h  
W-0h  
R/W-0h  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 49. Register 0h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
CTRL K  
R/W  
0h  
This bit is the enable bit for a number of frames per multiframe.  
0 = Default is five frames per multiframe  
1 = Frames per multiframe can be set in register 06h  
6-5  
4
0
W
0h  
0h  
Must write 0  
TESTMODE EN  
R/W  
This bit generates the long transport layer test pattern mode, as  
per section 5.1.6.3 of the JESD204B specification.  
0 = Test mode disabled  
1 = Test mode enabled  
3
2
FLIP ADC DATA  
LANE ALIGN  
R/W  
R/W  
0h  
0h  
0 = Normal operation  
1 = Output data order is reversed: MSB to LSB.  
This bit inserts the lane alignment character (K28.3) for the  
receiver to align to the lane boundary, as per section 5.3.3.5 of  
the JESD204B specification.  
0 = Normal operation  
1 = Inserts lane alignment characters  
1
0
FRAME ALIGN  
TX LINK DIS  
R/W  
R/W  
0h  
0h  
This bit inserts the lane alignment character (K28.7) for the  
receiver to align to the lane boundary, as per section 5.3.3.5 of  
the JESD204B specification.  
0 = Normal operation  
1 = Inserts frame alignment characters  
This bit disables sending the initial link alignment (ILA) sequence  
when SYNC is deasserted.  
0 = Normal operation  
1 = ILA disabled  
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8.5.3.5.2 Register 1h (address = 1h), JESD Digital Page (6900h)  
Figure 113. Register 1h  
7
6
5
4
3
2
1
0
SYNC REG  
R/W-0h  
SYNC REG EN  
R/W-0h  
JESD FILTER  
R/W-0h  
JESD MODE  
R/W-01h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 50. Register 1h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
SYNC REG  
R/W  
0h  
This bit is the register control for the sync request.  
0 = Normal operation  
1 = ADC output data are replaced with K28.5 characters; the SYNC  
REG EN register bit must also be set to 1  
6
SYNC REG EN  
JESD FILTER  
R/W  
R/W  
0h  
0h  
This bit enables register control for the sync request.  
0 = Use the SYNC pin for sync requests  
1 = Use the SYNC REG register bit for sync requests  
5-3  
These bits and the JESD MODE bits set the correct LMFS  
configuration for the JESD interface. The JESD FILTER setting  
must match the configuration in the decimation filter page.  
000 = Filter bypass mode  
See Table 51 for valid combinations for register bits JESD FILTER  
along with JESD MODE.  
2-0  
JESD MODE  
R/W  
01h  
These bits select the number of serial JESD output lanes per ADC.  
The JESD PLL MODE register bit located in the JESD analog page  
must also be set accordingly.  
001 = Default after reset(Eight active lanes)  
See Table 51 for valid combinations for register bits JESD FILTER  
along with JESD MODE.  
Table 51. Valid Combinations for JESD FILTER and JESD MODE Bits  
NUMBER OF ACTIVE LANES  
PER DEVICE  
REGISTER BIT JESD FILTER  
REGISTER BIT JESD MODE  
DECIMATION FACTOR  
000  
000  
100  
010  
No decimation  
No decimation  
Four lanes are active  
Four lanes are active  
No decimation  
(default after reset)  
000  
001  
Eight lanes are active  
111  
110  
110  
100  
111  
100  
001  
001  
010  
001  
010  
010  
4X (IQ)  
2X  
Four lanes are active  
Four lanes are active  
Two lanes are active  
Two lanes are active  
Two lanes are active  
One lane is active  
2X  
4X  
4X (IQ)  
4X  
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8.5.3.5.3 Register 2h (address = 2h), JESD Digital Page (6900h)  
Figure 114. Register 2h  
7
6
5
4
3
2
0
1
0
0
0
LINK LAYER TESTMODE  
R/W-0h  
LINK LAYER RPAT  
R/W-0h  
LMFC MASK RESET  
R/W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 52. Register 2h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-5  
LINK LAYER TESTMODE  
R/W  
0h  
These bits generate a pattern as per section 5.3.3.8.2 of the  
JESD204B document.  
000 = Normal ADC data  
001 = D21.5 (high-frequency jitter pattern)  
010 = K28.5 (mixed-frequency jitter pattern)  
011 = Repeat initial lane alignment (generates a K28.5 character  
and continuously repeats lane alignment sequences)  
100 = 12-octet RPAT jitter pattern  
All others = Not used  
4
LINK LAYER RPAT  
R/W  
0h  
This bit changes the running disparity in the modified RPAT pattern  
test mode (only when the link layer test mode = 100).  
0 = Normal operation  
1 = Changes disparity  
3
LMFC MASK RESET  
0
R/W  
W
0h  
0h  
This bit masks the LMFC reset coming to the digital block.  
0 = LMFC reset is not masked  
1 = Ignore the LMFC reset request  
2-0  
Must write 0  
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8.5.3.5.4 Register 3h (address = 3h), JESD Digital Page (6900h)  
Figure 115. Register 3h  
7
6
5
4
3
2
1
0
FORCE LMFC COUNT  
R/W-0h  
LMFC COUNT INIT  
R/W-0h  
RELEASE ILANE SEQ  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 53. Register 3h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
FORCE LMFC COUNT  
R/W  
0h  
This bit forces the LMFC count.  
0 = Normal operation  
1 = Enables using a different starting value for the LMFC counter  
6-2  
1-0  
MASK SYSREF  
R/W  
R/W  
0h  
0h  
When SYSREF transmits to the digital block, the LMFC count resets to  
0 and K28.5 stops transmitting when the LMFC count reaches 31. The  
initial value that the LMFC count resets to can be set using LMFC  
COUNT INIT. In this manner, the receiver can be synchronized early  
because the LANE ALIGNMENT SEQUENCE is received early. The  
FORCE LMFC COUNT register bit must be enabled.  
RELEASE ILANE SEQ  
These bits delay the generation of the lane alignment sequence by 0, 1,  
2, or 3 multiframes after the code group synchronization.  
00 = 0  
01 = 1  
10 = 2  
11 = 3  
8.5.3.5.5 Register 5h (address = 5h), JESD Digital Page (6900h)  
Figure 116. Register 5h  
7
6
0
5
4
3
2
0
1
0
0
0
SCRAMBLE EN  
R/W-Undefined  
0
0
0
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 54. Register 5h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7
SCRAMBLE EN  
R/W  
Undefined This bit is the scramble enable bit in the JESD204B interface.  
0 = Scrambling disabled  
1 = Scrambling enabled  
6-0  
0
W
0h  
Must write 0  
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8.5.3.5.6 Register 6h (address = 6h), JESD Digital Page (6900h)  
Figure 117. Register 6h  
7
0
6
0
5
0
4
3
2
1
0
FRAMES PER MULTI FRAME (K)  
R/W-8h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 55. Register 6h Field Descriptions  
Bit  
7-5  
4-0  
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
FRAMES PER MULTI FRAME (K)  
R/W  
8h  
These bits set the number of multiframes.  
Actual K is the value in hex + 1 (that is, 0Fh is K = 16).  
8.5.3.5.7 Register 7h (address = 7h), JESD Digital Page (6900h)  
Figure 118. Register 7h  
7
0
6
0
5
0
4
3
2
0
1
0
0
0
0
SUBCLASS  
R/W-1h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 56. Register 7h Field Descriptions  
Bit  
7-4  
3
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
SUBCLASS  
R/W  
1h  
This bit sets the JESD204B subclass.  
000 = Subclass 0 is backward compatible with JESD204A  
001 = Subclass 1 deterministic latency using the SYSREF signal  
2-0  
0
W
0h  
Must write 0  
8.5.3.5.8 Register 16h (address = 16h), JESD Digital Page (6900h)  
Figure 119. Register 16h  
7
1
6
0
5
0
4
3
0
2
0
1
0
0
0
LANE SHARE  
W-0h  
W-1h  
W-0h  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 57. Register 16h Field Descriptions  
Bit  
7
Field  
Type  
W
Reset  
1h  
Description  
Must write 1  
Must write 0  
1
6-5  
4
0
W
0h  
LANE SHARE  
R/W  
0h  
When using decimate-by-4, the data of both channels are output  
over one lane (LMFS = 1241).  
0 = Normal operation (each channel uses one lane)  
1 = Lane sharing is enabled, both channels share one lane  
(LMFS = 1241)  
3-0  
0
W
0h  
Must write 0  
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8.5.3.5.9 Register 31h (address = 31h), JESD Digital Page (6900h)  
Figure 120. Register 31h  
7
6
5
4
3
2
1
0
DA_BUS_REORDER[7:0]  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 58. Register 31h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-0  
DA_BUS_REORDER[7:0]  
R/W  
0h  
Use these bits to program output connections between data  
streams and output lanes in decimate-by-2 and decimate-by-4  
mode. Table 14 lists the supported combinations of these bits.  
8.5.3.5.10 Register 32h (address = 32h), JESD Digital Page (6900h)  
Figure 121. Register 32h  
7
6
5
4
3
2
1
0
DB_BUS_REORDER[7:0]  
R/W-0h  
LEGEND: R/W = Read/Write; -n = value after reset  
Table 59. Register 32h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-0  
DB_BUS_REORDER[7:0]  
R/W  
0h  
Use these bits to program output connections between data  
streams and output lanes in decimate-by-2 and decimate-by-4  
mode. Table 14 lists the supported combinations of these bits.  
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8.5.3.6 JESD Analog Page (6A00h) Registers  
8.5.3.6.1 Registers 12h-5h (addresses = 12h-5h), JESD Analog Page (6A00h)  
Figure 122. Register 12h  
7
6
5
4
3
2
2
2
2
1
0
0
0
SEL EMP LANE 1  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
W-0h  
W-0h  
Figure 123. Register 13h  
7
6
5
4
3
1
0
0
0
SEL EMP LANE 0  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
W-0h  
W-0h  
Figure 124. Register 14h  
7
6
5
4
3
1
0
0
0
SEL EMP LANE 2  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
W-0h  
W-0h  
Figure 125. Register 15h  
7
6
5
4
3
1
0
0
0
SEL EMP LANE 3  
R/W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
W-0h  
W-0h  
Table 60. Registers 12h-15h Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-2  
SEL EMP LANE x  
(where x = 1, 0, 2, or 3)  
R/W  
0h  
These bits select the amount of de-emphasis for the JESD  
output transmitter. The de-emphasis value in decibels (dB) is  
measured as the ratio between the peak value after the signal  
transition to the settled value of the voltage in one bit period.  
000000 = 0 dB  
000001 = –1 dB  
000011 = –2 dB  
000111 = –4.1 dB  
001111 = –6.2 dB  
011111 = –8.2 dB  
111111 = –11.5 dB  
1-0  
0
W-0h  
0h  
Must write 0  
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8.5.3.6.2 Register 16h (address = 16h), JESD Analog Page (6A00h)  
Figure 126. Register 16h  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
JESD PLL MODE  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 61. Register 16h Field Descriptions  
Bit  
7-2  
1-0  
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
JESD PLL MODE  
R/W  
0h  
These bits select the JESD PLL multiplication factor and must  
match the JESD MODE setting.  
00 = 20X mode  
01 = Not used  
10 = 40X mode  
11 = Not used  
See Table 14 for a programming summary of the DDC modes  
and JESD link configuration.  
8.5.3.6.3 Register 17h (address = 17h), JESD Analog Page (6A00h)  
Figure 127. Register 17h  
7
0
6
5
0
4
0
3
0
2
0
1
0
0
0
PLL RESET  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 62. Register 17h Field Descriptions  
Bit  
7
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
6
PLL RESET  
R/W  
0h  
Pulse this bit after powering up the device; see Table 65.  
0 = Default  
0 1 0 = The PLL RESET bit is pulsed.  
5-0  
0
W
0h  
Must write 0  
8.5.3.6.4 Register 1Ah (address = 1Ah), JESD Analog Page (6A00h)  
Figure 128. Register 1Ah  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
FOVR CHA  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 63. Register 1Ah Field Descriptions  
Bit  
7-2  
1
Field  
Type  
W
Reset  
0h  
Description  
0
Must write 0  
FOVR CHA  
R/W  
0h  
This bit outputs the FOVR signal for channel A on the PDN pin.  
FOVR CHA EN (register 1Bh, bit 3) must be enabled for this bit  
to function.  
0 = Normal operation  
1 = The FOVR signal of channel A is available on the PDN pin  
0
0
W
0h  
Must write 0  
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8.5.3.6.5 Register 1Bh (address = 1Bh), JESD Analog Page (6A00h)  
Figure 129. Register 1Bh  
7
6
5
4
0
3
2
0
1
0
0
0
JESD SWING  
R/W-0h  
FOVR CHA EN  
R/W-0h  
W-0h  
W-0h  
W-0h  
W-0h  
LEGEND: R/W = Read/Write; W = Write only; -n = value after reset  
Table 64. Register 1Bh Field Descriptions  
Bit  
Field  
Type  
Reset  
Description  
7-5  
JESD SWING  
R/W  
0h  
These bits select the output amplitude VOD (mVPP) of the JESD  
transmitter (for all lanes).  
0 = 860 mVPP  
1 = 810 mVPP  
2 = 770 mVPP  
3 = 745 mVPP  
4 = 960 mVPP  
5 = 930 mVPP  
6 = 905 mVPP  
7 = 880 mVPP  
4
3
0
W
0h  
0h  
Must write 0  
FOVR CHA EN  
R/W  
This bit enables overwrites of the PDN pin with the FOVR signal  
from channel A.  
0 = Normal operation  
1 = PDN is overwritten  
2-0  
0
W
0h  
Must write 0  
9 Application and Implementation  
NOTE  
Information in the following applications sections is not part of the TI component  
specification, and TI does not warrant its accuracy or completeness. TI’s customers are  
responsible for determining suitability of components for their purposes. Customers should  
validate and test their design implementation to confirm system functionality.  
9.1 Application Information  
9.1.1 Start-Up Sequence  
The steps described in Table 65 are recommended as the power-up sequence with the ADS54J20 in 20X mode  
(LMFS = 8224).  
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Table 65. Initialization Sequence  
PAGE BEING  
PROGRAMMED  
STEP  
1
SEQUENCE  
Power-up the device  
DESCRIPTION  
COMMENT  
Bring up IOVDD to 1.15 V before applying power to DVDD. Bring up  
DVDD to 1.9 V, AVDD to 1.9 V, and AVDD3V to 3.0 V.  
See the Power Sequencing and Initialization section for power sequence  
requirements.  
Hardware reset  
Apply a hardware reset by pulsing pin 48 (low high low).  
Register writes are equivalent to a hardware reset.  
A hardware reset clears all registers to their default values.  
Reset registers in the ADC and master pages of the analog bank.  
This bit is a self-clearing bit.  
Write address 0-000h with 81h.  
General register  
2
Reset the device  
Write address 4-001h with 00h and address 4-002h with 00h.  
Write address 4-003h with 00h and address 4-004h with 68h.  
Unused page  
Clear any unwanted content from the unused pages of the JESD bank.  
Select the main digital page of the JESD bank.  
Use the DIG RESET register bit to reset all pages in the JESD bank.  
This bit is a self-clearing bit.  
Write address 6-0F7h with 01h for channel A.  
Main digital page  
(JESD bank)  
Write address 6-000h with 01h, then address 6-000h with 00h.  
Write address 0-011h with 80h.  
Pulse the PULSE RESET register bit for channel A.  
Select the master page of the analog bank.  
3
Performance modes  
Master page  
(analog bank)  
Write address 0-059h with 20h.  
Set the ALWAYS WRITE 1 bit.  
Default register writes for DDC modes and JESD link configuration (LMFS = 8224).  
Write address 4-003h with 00h and address 4-004h with 69h.  
Write address 6-000h with 80h.  
Select the JESD digital page.  
Set the CTRL K bit for both channels by programming K according to the  
SYSREF signal later on in the sequence.  
JESD  
digital page  
(JESD bank)  
See Table 14 for configuring the JESD digital page registers for the desired  
LMFS and programming appropriate DDC mode.  
JESD link is configured with LMFS = 8224 by default with no decimation.  
Write address 4-003h with 00h and address 4-004h with 6Ah.  
Select the JESD analog page.  
Program desired registers for  
decimation options and  
JESD link configuration  
See Table 14 for configuring the JESD analog page registers for the desired  
LMFS and programming appropriate DDC mode.  
4
JESD link is configured with LMFS = 8224 by default with no decimation.  
JESD  
analog page  
(JESD bank)  
Write address 6-017h with 40h.  
PLL reset.  
Write address 6-017h with 00h.  
PLL reset clear.  
Write address 4-003h with 00h and address 4-004h with 68h.  
Select the main digital page.  
See Table 14 for configuring the main digital page registers for the desired  
LMFS and programming appropriate DDC mode.  
JESD link is configured with LMFS = 8224 by default with no decimation.  
Write address 6-000h with 01h and address 6-000h with 00h.  
Main digital page  
(JESD bank)  
Pulse the PULSE RESET register bit. All settings programmed in the main  
digital page take effect only after this bit is pulsed.  
Copyright © 2016–2017, Texas Instruments Incorporated  
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Table 65. Initialization Sequence (continued)  
PAGE BEING  
STEP  
SEQUENCE  
DESCRIPTION  
PROGRAMMED  
COMMENT  
Write address 4-003h with 00h and address 4-004h with 69h.  
Select the JESD digital page.  
Set the value of K and the  
SYSREF signal frequency  
accordingly  
JESD  
digital page  
(JESD bank)  
5
Write address 6-006h with XXh (choose the value of K).  
See the SYSREF Signal section to choose the correct frequency for SYSREF.  
Pull the SYNCB pin (pin 63) low.  
Pull the SYNCB pin high.  
Transmit K28.5 characters.  
6
JESD lane alignment  
After the receiver is synchronized, initiate an ILA phase and subsequent  
transmissions of ADC data.  
70  
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9.1.2 Hardware Reset  
Figure 130 and Table 66 show the timing for a hardware reset.  
Power Supplies  
tPU  
RESET  
tRST  
tWR  
SEN  
Figure 130. Hardware Reset Timing Diagram  
Table 66. Timing Requirements for Figure 130  
MIN  
TYP  
MAX  
UNIT  
ms  
ns  
tPU  
Power-on delay from power-up to an active high RESET pulse  
Reset pulse duration: active high RESET pulse duration  
Register write delay from RESET disable to SEN active  
1
10  
tRST  
tWR  
100  
ns  
9.1.3 SNR and Clock Jitter  
The signal-to-noise ratio (SNR) of the ADC is limited by three different factors: quantization noise, thermal noise,  
and jitter, as shown in Equation 4. The quantization noise is typically not noticeable in pipeline converters and is  
74 dBFS for a 12-bit ADC. The thermal noise limits SNR at low input frequencies and the clock jitter sets SNR for  
higher input frequencies.  
(4)  
The SNR limitation resulting from sample clock jitter can be calculated by Equation 5:  
(5)  
The total clock jitter (TJitter) has two components: the internal aperture jitter (130 fS) is set by the noise of the  
clock input buffer and the external clock jitter. TJitter can be calculated by Equation 6:  
(6)  
External clock jitter can be minimized by using high-quality clock sources and jitter cleaners as well as band-pass  
filters at the clock input. A faster clock slew rate also improves the ADC aperture jitter.  
Copyright © 2016–2017, Texas Instruments Incorporated  
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The ADS54J20 has a thermal noise of approximately 71.1 dBFS and an internal aperture jitter of 120 fS. SNR,  
depending on the amount of external jitter for different input frequencies, is shown in Figure 131.  
71  
35 fs  
50 fs  
100 fs  
150 fs  
200 fs  
69  
67  
65  
63  
10  
100  
Input Frequency (MHz)  
500  
D057  
Figure 131. SNR versus Input Frequency and External Clock Jitter  
72  
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9.2 Typical Application  
The ADS54J20 is designed for wideband receiver applications demanding excellent dynamic range over a large  
input frequency range. A typical schematic for an ac-coupled receiver is shown in Figure 132.  
DVDD  
10 k  
5 W  
5 W  
50 W  
50 W  
Driver  
0.1 mF  
2 pF  
0.1 mF  
SPI Master  
GND  
GND  
IOVDD GND  
0.1 mF  
0.1 mF  
0.1 mF  
10nF  
GND  
0.1 mF  
AVDD3V  
AVDD  
AVDD  
AVDD3V  
DVDD  
100-W Differential  
18  
17  
16  
15  
14  
13  
12  
11  
10  
9
8
7
6
5
4
3
2
1
10 nF  
DB2P  
DB2M  
IOVDD  
DB1P  
DB1M  
DGND  
DB0P  
DB0M  
IOVDD  
SYNC  
DA0M  
DA0P  
DGND  
DA1M  
DA1P  
IOVDD  
DA2M  
DA2P  
NC  
NC  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
72  
71  
70  
69  
68  
67  
66  
65  
64  
63  
62  
61  
60  
59  
58  
57  
56  
55  
IOVDD  
10 nF  
GND  
NC  
10 nF  
10 nF  
VCM  
0.1 mF  
AGND  
AVDD3V  
AVDD  
AGND  
CLKINP  
CLKINM  
AGND  
AVDD  
AVDD3V  
AGND  
GND  
0.1 mF  
AVDD3V  
GND  
AVDD  
0.1 mF  
GND  
10 nF  
IOVDD  
0.1 mF  
GND  
GND Pad  
(Back Side)  
GND  
0.1 mF  
FPGA  
Low-Jitter Clock  
Generator  
AVDD3V  
0.1 mF  
GND  
10 nF  
10 nF  
GND  
SYSREFP  
SYSREFM  
AVDD  
100 W  
IOVDD  
10 nF  
GND  
AVDD  
AGND  
GND  
10 nF  
10 nF  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
100-W Differential  
AVDD3V  
DVDD  
AVDD  
AVDD  
AVDD3V  
0.1 mF  
GND  
GND  
0.1 mF  
IOVDD GND  
0.1 mF  
GND  
5 W  
5 W  
50 W  
50 W  
Driver  
0.1 mF  
0.1 mF  
2 pF  
GND  
Copyright © 2016, Texas Instruments Incorporated  
NOTE: GND = AGND and DGND are connected in the PCB layout.  
Figure 132. AC-Coupled Receiver  
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Typical Application (continued)  
9.2.1 Design Requirements  
9.2.1.1 Transformer-Coupled Circuits  
Typical applications involving transformer-coupled circuits are discussed in this section. Transformers (such as  
ADT1-1WT or WBC1-1) can be used up to 300 MHz to achieve good phase and amplitude balances at the ADC  
inputs. When designing dc-driving circuits, the ADC input impedance must be considered. Figure 133 and  
Figure 134 show the impedance (ZIN = RIN || CIN) across the ADC input pins.  
5
4.75  
4.5  
1.4  
1.2  
1
4.25  
4
0.8  
0.6  
0.4  
0.2  
0
3.75  
3.5  
3.25  
3
2.75  
2.5  
2.25  
0
100 200 300 400 500 600 700 800 900 1000  
0
100 200 300 400 500 600 700 800 900 1000  
Frequency (MHz)  
Frequency (MHz)  
D103  
D102  
Figure 133. RIN vs Input Frequency  
Figure 134. CIN vs Input Frequency  
By using the simple drive circuit of Figure 135, uniform performance can be obtained over a wide frequency  
range. The buffers present at the analog inputs of the device help isolate the external drive source from the  
switching currents of the sampling circuit.  
0.1 F  
T2  
CHx_INP  
T1  
5 ꢀ  
0.1 F  
25 ꢀ  
0.1 F  
RIN  
CIN  
25 ꢀ  
5 ꢀ  
0.1 F  
CHx_INM  
1:1  
1:1  
TI Device  
Copyright © 2016, Texas Instruments Incorporated  
Figure 135. Input Drive Circuit  
9.2.2 Detailed Design Procedure  
For optimum performance, the analog inputs must be driven differentially. This architecture improves common-  
mode noise immunity and even-order harmonic rejection. A small resistor (5 Ω to 10 Ω) in series with each input  
pin is recommended to damp out ringing caused by package parasitics, as shown in Figure 135.  
74  
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Typical Application (continued)  
9.2.3 Application Curves  
Figure 136 and Figure 137 show the typical performance at 170 MHz and 230 MHz, respectively.  
0
-20  
0
-20  
-40  
-40  
-60  
-60  
-80  
-80  
-100  
-120  
-100  
-120  
0
100  
200  
300  
400  
500  
0
100  
200  
300  
400  
500  
Input Frequency (MHz)  
Input Frequency (MHz)  
D003  
D004  
SNR = 67.8 dBFS, SINAD = 67.7 dBFS,  
SNR = 67.4 dBFS, SINAD = 67.2 dBFS,  
SFDR = 86 dBc, THD = 81 dBc, IL spur = 88 dBc,  
non HD2, HD3 spur = 89 dBc  
IL spur = 87 dBc, SFDR = 84 dBc, THD = 82 dBc,  
non HD2, HD3 spur = 90 dBc  
Figure 136. FFT for 170-MHz Input Signal  
Figure 137. FFT for 230-MHz Input Signal  
10 Power Supply Recommendations  
The device requires a 1.15-V nominal supply for IOVDD, a 1.9-V nominal supply for DVDD, a 1.9-V nominal  
supply for AVDD, and a 3.0-V nominal supply for AVDD3V. For detailed information regarding the operating  
voltage minimum and maximum specifications of different supplies, see the Recommended Operating Conditions  
table.  
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10.1 Power Sequencing and Initialization  
Figure 138 shows the suggested power-up sequencing for the device. Note that the 1.15-V IOVDD supply must  
rise before the 1.9-V DVDD supply. If the 1.9-V DVDD supply rises before the 1.15-V IOVDD supply, then the  
internal default register settings may not load properly. The other supplies (the 3-V AVDD3V and the 1.9-V  
AVDD), can come up in any order during the power sequence. The power supplies can ramp up at any rate and  
there is no hard requirement for the time delay between IOVDD ramp up to DVDD ramp-up (can be in orders of  
microseconds but is recommend to be a few milliseconds).  
IOVDD = 1.15 V  
DVDD = 1.9 V  
AVDD = 1.9 V  
AVDD = 3 V  
Figure 138. Power Sequencing for the ADS54Jxx Family of Devices  
76  
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11 Layout  
11.1 Layout Guidelines  
The device evaluation module (EVM) layout can be used as a reference layout to obtain the best performance. A  
layout diagram of the EVM top layer is provided in Figure 139. The ADS54J20EVM User's Guide (SLAU687),  
provides a complete layout of the EVM. Some important points to remember during board layout are:  
Analog inputs are located on opposite sides of the device pinout to ensure minimum crosstalk on the package  
level. To minimize crosstalk onboard, the analog inputs must exit the pinout in opposite directions, as  
illustrated in the reference layout of Figure 139 as much as possible.  
In the device pinout, the sampling clock is located on a side perpendicular to the analog inputs in order to  
minimize coupling between them. This configuration is also maintained on the reference layout of Figure 139  
as much as possible.  
Keep digital outputs away from the analog inputs. When these digital outputs exit the pinout, the digital output  
traces must not be kept parallel to the analog input traces because this configuration can result in coupling  
from the digital outputs to the analog inputs and degrade performance. All digital output traces to the receiver  
[such as a field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs)] must  
be matched in length to avoid skew among outputs.  
At each power-supply pin (AVDD, DVDD, or AVDDD3V), keep a 0.1-µF decoupling capacitor close to the  
device. A separate decoupling capacitor group consisting of a parallel combination of 10-µF, 1-µF, and 0.1-µF  
capacitors can be kept close to the supply source.  
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11.2 Layout Example  
Copyright © 2016, Texas Instruments Incorporated  
Figure 139. ADS54J20EVM Layout  
78  
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12 器件和文档支持  
12.1 文档支持  
12.1.1 相关文档ꢀ  
相关文档如下:  
ADS54J40 双通道 14 1.0GSPS 模数转换器  
ADS54J42 双通道、14 位、625MSPS 模数转换器  
ADS54J60 双通道 16 1.0GSPS 模数转换器  
ADS54J66 具有集成 DDC 的四通道、14 位、500MSPS ADC  
ADS54J69 双通道、16 位、500 MSPS 模数转换器  
ADS54J20EVM 用户指南》  
12.2 接收文档更新通知  
如需接收文档更新通知,请访问 www.ti.com.cn 网站上的器件产品文件夹。点击右上角的提醒我 (Alert me) 注册  
后,即可每周定期收到已更改的产品信息。有关更改的详细信息,请查阅已修订文档中包含的修订历史记录。  
12.3 社区资源  
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective  
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of  
Use.  
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration  
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help  
solve problems with fellow engineers.  
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and  
contact information for technical support.  
12.4 商标  
E2E is a trademark of Texas Instruments.  
All other trademarks are the property of their respective owners.  
12.5 静电放电警告  
ESD 可能会损坏该集成电路。德州仪器 (TI) 建议通过适当的预防措施处理所有集成电路。如果不遵守正确的处理措施和安装程序 , 可  
能会损坏集成电路。  
ESD 的损坏小至导致微小的性能降级 , 大至整个器件故障。 精密的集成电路可能更容易受到损坏 , 这是因为非常细微的参数更改都可  
能会导致器件与其发布的规格不相符。  
12.6 Glossary  
SLYZ022 TI Glossary.  
This glossary lists and explains terms, acronyms, and definitions.  
13 机械、封装和可订购信息  
以下页中包括机械、封装和可订购信息。这些信息是针对指定器件可提供的最新数据。这些数据会在无通知且不对  
本文档进行修订的情况下发生改变。欲获得该数据表的浏览器版本,请查阅左侧的导航栏。  
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79  
PACKAGE OPTION ADDENDUM  
www.ti.com  
10-Dec-2020  
PACKAGING INFORMATION  
Orderable Device  
Status Package Type Package Pins Package  
Eco Plan  
Lead finish/  
Ball material  
MSL Peak Temp  
Op Temp (°C)  
Device Marking  
Samples  
Drawing  
Qty  
(1)  
(2)  
(3)  
(4/5)  
(6)  
ADS54J20IRMP  
ADS54J20IRMPT  
ACTIVE  
ACTIVE  
VQFN  
VQFN  
RMP  
RMP  
72  
72  
168  
250  
RoHS & Green  
RoHS & Green  
NIPDAU  
Level-3-260C-168 HR  
Level-3-260C-168 HR  
-40 to 85  
-40 to 85  
AZ54J20  
AZ54J20  
NIPDAU  
(1) The marketing status values are defined as follows:  
ACTIVE: Product device recommended for new designs.  
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.  
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.  
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.  
OBSOLETE: TI has discontinued the production of the device.  
(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance  
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may  
reference these types of products as "Pb-Free".  
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.  
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based  
flame retardants must also meet the <=1000ppm threshold requirement.  
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.  
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.  
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation  
of the previous line and the two combined represent the entire Device Marking for that device.  
(6)  
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two  
lines if the finish value exceeds the maximum column width.  
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information  
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and  
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.  
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.  
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.  
Addendum-Page 1  
PACKAGE OPTION ADDENDUM  
www.ti.com  
10-Dec-2020  
Addendum-Page 2  
PACKAGE MATERIALS INFORMATION  
www.ti.com  
5-Jan-2022  
TRAY  
Chamfer on Tray corner indicates Pin 1 orientation of packed units.  
*All dimensions are nominal  
Device  
Package Package Pins SPQ Unit array  
Max  
matrix temperature  
(°C)  
L (mm)  
W
K0  
P1  
CL  
CW  
Name  
Type  
(mm) (µm) (mm) (mm) (mm)  
ADS54J20IRMP  
RMP  
VQFNP  
72  
168  
8 X 21  
150  
315 135.9 7620 14.65  
11  
11.95  
Pack Materials-Page 1  
PACKAGE OUTLINE  
RMP0072A  
VQFN - 0.9 mm max height  
SCALE 1.700  
VQFN  
10.1  
9.9  
A
B
PIN 1 ID  
10.1  
9.9  
0.9 MAX  
0.05  
0.00  
C
SEATING PLANE  
0.08 C  
(0.2)  
4X (45 X0.42)  
19  
36  
18  
37  
SYMM  
4X  
8.5  
8.5 0.1  
PIN 1 ID  
(R0.2)  
1
54  
0.30  
0.18  
72X  
72  
55  
68X 0.5  
SYMM  
0.5  
0.3  
0.1  
C B  
A
72X  
0.05  
C
4221047/B 02/2014  
NOTES:  
1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing  
per ASME Y14.5M.  
2. This drawing is subject to change without notice.  
3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.  
www.ti.com  
EXAMPLE BOARD LAYOUT  
RMP0072A  
VQFN - 0.9 mm max height  
VQFN  
(
8.5)  
SYMM  
72X (0.6)  
SEE DETAILS  
55  
72  
1
54  
72X (0.24)  
(0.25) TYP  
SYMM  
(9.8)  
(1.315) TYP  
68X (0.5)  
(
0.2) TYP  
VIA  
37  
18  
19  
36  
(1.315) TYP  
(9.8)  
LAND PATTERN EXAMPLE  
SCALE:8X  
0.07 MAX  
ALL AROUND  
0.07 MIN  
ALL AROUND  
SOLDER MASK  
OPENING  
METAL  
SOLDER MASK  
OPENING  
METAL  
NON SOLDER MASK  
DEFINED  
SOLDER MASK  
DEFINED  
(PREFERRED)  
SOLDER MASK DETAILS  
4221047/B 02/2014  
NOTES: (continued)  
4. This package is designed to be soldered to a thermal pad on the board. For more information, see QFN/SON PCB application report  
in literature No. SLUA271 (www.ti.com/lit/slua271).  
www.ti.com  
EXAMPLE STENCIL DESIGN  
RMP0072A  
VQFN - 0.9 mm max height  
VQFN  
(9.8)  
72X (0.6)  
(1.315) TYP  
72  
55  
1
54  
72X (0.24)  
(1.315)  
TYP  
(0.25) TYP  
SYMM  
(9.8)  
(1.315)  
TYP  
68X (0.5)  
METAL  
TYP  
37  
18  
(
0.2) TYP  
VIA  
19  
36  
36X ( 1.115)  
(1.315) TYP  
SYMM  
SOLDER PASTE EXAMPLE  
BASED ON 0.125 mm THICK STENCIL  
EXPOSED PAD  
62% PRINTED SOLDER COVERAGE BY AREA  
SCALE:8X  
4221047/B 02/2014  
NOTES: (continued)  
5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate  
design recommendations.  
www.ti.com  
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