MAX1180ECM+D [MAXIM]

ADC, Flash Method, 10-Bit, 1 Func, 2 Channel, Parallel, Word Access, PQFP48, 7 X 7 MM, 1 MM HEIGHT, ROHS COMPLIANT, MS-026ABA-HD, TQFP-48;
MAX1180ECM+D
型号: MAX1180ECM+D
厂家: MAXIM INTEGRATED PRODUCTS    MAXIM INTEGRATED PRODUCTS
描述:

ADC, Flash Method, 10-Bit, 1 Func, 2 Channel, Parallel, Word Access, PQFP48, 7 X 7 MM, 1 MM HEIGHT, ROHS COMPLIANT, MS-026ABA-HD, TQFP-48

转换器
文件: 总21页 (文件大小:537K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
19-2097; Rev 1; 2/07  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
General Description  
Features  
The MAX1180 is a 3.3V, dual 10-bit, analog-to-digital  
converter (ADC) featuring fully-differential wideband  
track-and-hold (T/H) inputs, driving two pipelined, nine-  
stage ADCs. The MAX1180 is optimized for low-power,  
high-dynamic performance applications in imaging,  
instrumentation, and digital communication applica-  
tions. The MAX1180 operates from a single 2.7V to 3.6V  
supply, consuming only 413mW, while delivering a typi-  
cal signal-to-noise ratio (SNR) of 58.5dB at an input fre-  
quency of 20MHz and a sampling rate of 105Msps. The  
T/H driven input stages incorporate 400MHz (-3dB)  
input amplifiers. The converters may also be operated  
with single-ended inputs. In addition to low operating  
power, the MAX1180 features a 2.8mA sleep mode, as  
well as a 1µA power-down mode to conserve power  
during idle periods.  
Single 3.3V Operation  
Excellent Dynamic Performance  
58.5dB SNR at f = 20MHz  
IN  
72dB SFDR at f = 20MHz  
IN  
SNR Flat within 1dB for f = 20MHz to 100MHz  
IN  
Low Power  
125mA (Normal Operation)  
2.8mA (Sleep Mode)  
1µA (Shutdown Mode)  
0.02dB Gain and 0.25° Phase Matching (typ)  
Wide 1V  
Differential Analog Input Voltage  
P-P  
Range  
400MHz, -3dB Input Bandwidth  
On-Chip 2.048V Precision Bandgap Reference  
An internal 2.048V precision bandgap reference sets  
the full-scale range of the ADC. A flexible reference  
structure allows the use of the internal or external  
reference, if desired for applications requiring  
increased accuracy or a different input voltage range.  
User-Selectable Output Format—Two’s  
Complement or Offset Binary  
48-Pin TQFP Package with Exposed Pad for  
Improved Thermal Dissipation  
The MAX1180 features parallel, CMOS-compatible  
three-state outputs. The digital output format is set to  
two’s complement or straight offset binary through a  
single control pin. The device provides for a separate  
output power supply of 1.7V to 3.6V for flexible interfac-  
Ordering Information  
PART  
TEMP RANGE  
-40°C to +85°C  
-40°C to +85°C  
PIN-PACKAGE  
48 TQFP-EP*  
48 TQFP-EP*  
MAX1180ECM  
MAX1180ECM+  
ing. The MAX1180 is available in a 7mm 7mm, 48-pin  
+Denotes a lead-free and RoHS-compliant package.  
*EP = Exposed paddle.  
TQFP package, and is specified for the extended  
industrial (-40°C to +85°C) temperature range.  
Pin Configuration  
Pin-compatible higher and lower speed versions of the  
MAX1180 are also available. Please refer to the  
MAX1181 data sheet for 80Msps, the MAX1182 data  
sheet for 65Msps, the MAX1183 data sheet for 40Msps,  
and the MAX1184 data sheet for 20Msps. In addition to  
these speed grades, this family includes a 20Msps mul-  
tiplexed output version (MAX1185), for which digital  
data is presented time-interleaved on a single, parallel  
10-bit output port.  
COM  
1
2
36 D1A  
35 D0A  
34 OGND  
V
DD  
GND  
INA+  
INA-  
3
4
33 OV  
32 OV  
DD  
DD  
5
V
6
31 OGND  
30 D0B  
29 D1B  
28 D2B  
DD  
Applications  
High Resolution Imaging  
I/Q Channel Digitization  
MAX1180  
GND  
INB-  
INB+  
GND  
7
8
9
D3B  
D4B  
D5B  
10  
11  
12  
27  
26  
25  
EP  
V
DD  
Multichannel IF Undersampling  
Instrumentation  
CLK  
Video Application  
48 TQFP-EP  
Functional Diagram appears at end of data sheet.  
NOTE: THE PIN 1 INDICATOR FOR LEAD-FREE PACKAGES IS REPLACED  
BY A "+" SIGN.  
________________________________________________________________ Maxim Integrated Products  
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at  
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
ABSOLUTE MAXIMUM RATINGS  
V
, OV  
to GND ...............................................-0.3V to +3.6V  
Continuous Power Dissipation (T = +70°C)  
A
DD  
DD  
OGND to GND.......................................................-0.3V to +0.3V  
48-Pin TQFP-EP (derate 30.4mW/°C above +70°C)...2430mW  
Operating Temperature Range ...........................-40°C to +85°C  
Junction Temperature......................................................+150°C  
Storage Temperature Range.............................-60°C to +150°C  
Lead Temperature (soldering, 10s) .................................+300°C  
INA+, INA-, INB+, INB- to GND ...............................-0.3V to V  
REFIN, REFOUT, REFP, REFN, CLK,  
DD  
COM to GND ............................................-0.3V to (V + 0.3V)  
DD  
OE, PD, SLEEP, T/B, D9A–D0A,  
D9B–D0B to OGND ................................-0.3V to (OV + 0.3V)  
DD  
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional  
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to  
absolute maximum rating conditions for extended periods may affect device reliability.  
ELECTRICAL CHARACTERISTICS  
(V  
= 3.3V, OV  
= 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a  
DD  
DD  
10kresistor, V = 2V  
(differential with respect to COM), C = 10pF at digital outputs (Note 1), f  
= 105.263MHz, T = T  
to  
IN  
P-P  
L
CLK  
A
MIN  
T
MAX  
, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)  
A
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
DC ACCURACY  
Resolution  
10  
Bits  
LSB  
Integral Nonlinearity  
INL  
f
f
= 7.47MHz  
0.75  
0.4  
2.5  
+1.5  
+1.8  
2
IN  
Differential Nonlinearity  
Offset Error  
DNL  
= 7.47MHz, no missing codes guaranteed  
-1.0  
-1.8  
LSB  
IN  
% FS  
% FS  
Gain Error  
0
ANALOG INPUT  
Differential Input Voltage Range  
V
Differential or single-ended inputs  
Switched capacitor load  
1.0  
V
V
DIFF  
Common-Mode Input Voltage  
Range  
V
2
/
DD  
0.5  
V
CM  
Input Resistance  
R
20  
k  
IN  
IN  
Input Capacitance  
C
5
pF  
CONVERSION RATE  
Maximum Clock Frequency  
f
105  
MHz  
CLK  
Clock  
Cycles  
Data Latency  
5
DYNAMIC CHARACTERISTICS  
f
f
f
f
f
f
f
f
f
f
f
f
= 7.47MHz, T = +25°C  
59  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
INA or B  
A
Signal-to-Noise Ratio (Note 3)  
SNR  
SINAD  
SFDR  
THD  
= 20MHz, T = +25°C  
55  
54.7  
60  
58.5  
58  
dB  
dB  
A
= 50.078MHz  
= 7.47MHz, T = +25°C  
58.2  
58.1  
57.6  
72  
A
Signal-to-Noise and Distortion  
(Note 3)  
= 20MHz, T = +25°C  
A
= 50.078MHz  
= 7.47MHz, T = +25°C  
A
Spurious-Free Dynamic  
Range (Note 3)  
= 20MHz, T = +25°C  
72  
dBc  
dBc  
A
= 50.078MHz  
70  
= 7.47MHz, T = +25°C  
-71  
-70  
-69  
A
Total Harmonic Distortion  
(First Four Harmonics) (Note 3)  
= 20MHz, T = +25°C  
-59  
A
= 50.078MHz  
2
_______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
ELECTRICAL CHARACTERISTICS (continued)  
(V  
= 3.3V, OV  
= 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a  
DD  
DD  
10kresistor, V = 2V  
(differential with respect to COM), C = 10pF at digital outputs (Note 1), f  
= 105.263MHz, T = T  
to  
IN  
P-P  
L
CLK  
A
MIN  
T
MAX  
, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)  
A
PARAMETER  
SYMBOL  
CONDITIONS  
= 7.47MHz  
MIN  
TYP  
-75  
-75  
-73  
MAX UNITS  
f
f
f
INA or B  
INA or B  
INA or B  
Third-Harmonic Distortion  
(Note 3)  
HD3  
dBc  
dBc  
= 20MHz  
= 50.078MHz  
f
f
= 38.055MHz at -6.5dBFS  
= 42.926MHz at -6.5dBFS  
INA or B  
INA or B  
Intermodulation Distortion  
IMD  
-74  
(Note 4)  
Small-Signal Bandwidth  
Full-Power Bandwidth  
Aperture Delay  
Input at -20dBFS, differential inputs  
Input at -0.5dBFS, differential inputs  
500  
400  
1
MHz  
MHz  
ns  
FPBW  
t
AD  
Aperture Jitter  
t
2
ps  
RMS  
AJ  
Overdrive Recovery Time  
Differential Gain  
For 1.5 full-scale input  
2
ns  
1
%
Differential Phase  
Output Noise  
0.25  
0.2  
degrees  
LSB  
INA+ = INA- = INB+ = INB- = COM  
RMS  
INTERNAL REFERENCE  
2.048  
3%  
Reference Output Voltage  
REFOUT  
V
Reference Temperature  
Coefficient  
TC  
60  
ppm/°C  
mV/mA  
REF  
Load Regulation  
1.25  
BUFFERED EXTERNAL REFERENCE (V  
= 2.048V)  
REFIN  
REFIN Input Voltage  
V
2.048  
2.162  
V
V
REFIN  
Positive Reference Output  
Voltage  
V
REFP  
Negative Reference Output  
Voltage  
V
1.138  
V
REFN  
Differential Reference Output  
Voltage Range  
V  
V  
= V  
- V  
REFN  
0.95  
1.024  
> 50  
5
1.10  
V
REF  
REF  
REFP  
REFIN Resistance  
R
REFIN  
MΩ  
mA  
Maximum REFP, COM Source  
Current  
I
I
SOURCE  
Maximum REFP, COM Sink  
Current  
I
-250  
µA  
SINK  
Maximum REFN Source Current  
Maximum REFN Sink Current  
250  
-5  
µA  
SOURCE  
I
mA  
SINK  
_______________________________________________________________________________________  
3
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
ELECTRICAL CHARACTERISTICS (continued)  
(V  
= 3.3V, OV  
= 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a  
DD  
DD  
10kresistor, V = 2V  
(differential with respect to COM), C = 10pF at digital outputs (Note 1), f  
= 105.263MHz, T = T  
to  
IN  
P-P  
L
CLK  
A
MIN  
T
MAX  
, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)  
A
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
UNBUFFERED EXTERNAL REFERENCE (V  
= AGND, reference voltage applied to REFP, REFN, and COM )  
REFIN  
R
R
Measured between REFP and COM and  
REFN and COM  
REFP,  
REFP, REFN Input Resistance  
4
kΩ  
V
REFN  
Differential Reference Input  
Voltage Range  
1.024  
10%  
V  
V  
= V  
- V  
REFP REFN  
REF  
COM  
REFP  
REFN  
REF  
V
/ 2  
DD  
10%  
COM Input Voltage Range  
REFP Input Voltage  
V
V
V
V
V  
+
/ 2  
COM  
V
REF  
V
V  
-
/ 2  
COM  
REFN Input Voltage  
V
V
REF  
DIGITAL INPUTS (CLK, PD,  
, SLEEP, T/B)  
0.8 x  
CLK  
V
DD  
Input High Threshold  
Input Low Threshold  
V
V
V
IH  
0.8 x  
OV  
PD, OE, SLEEP, T/B  
CLK  
DD  
0.2 x  
V
DD  
V
IL  
0.2 x  
OV  
PD, OE, SLEEP, T/B  
DD  
Input Hysteresis  
Input Leakage  
V
0.1  
5
V
HYST  
I
IH  
V
V
= OV or V (CLK)  
5
5
IH  
IL  
DD  
DD  
µA  
pF  
I
IL  
= 0  
Input Capacitance  
C
IN  
DIGITAL OUTPUTS (D9A–D0A, D9B–D0B)  
Output-Voltage Low  
V
I
I
= -200µA  
0.2  
10  
V
V
OL  
SINK  
OV  
- 0.2  
DD  
Output-Voltage High  
V
= 200µA  
SOURCE  
OH  
Three-State Leakage Current  
Three-State Output Capacitance  
POWER REQUIREMENTS  
Analog Supply Voltage Range  
Output Supply Voltage Range  
I
OE = OV  
OE = OV  
µA  
pF  
LEAK  
DD  
C
5
OUT  
DD  
V
2.7  
1.7  
3.3  
2.5  
125  
2.8  
1
3.6  
3.6  
156  
V
V
DD  
OV  
DD  
Operating, f  
Sleep mode  
= 20MHz at -0.5dBFS  
INA or B  
mA  
µA  
Analog Supply Current  
I
VDD  
Shutdown, clock idle, PD = OE = OV  
15  
DD  
4
_______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
ELECTRICAL CHARACTERISTICS (continued)  
(V  
= 3.3V, OV  
= 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a  
DD  
DD  
10kresistor, V = 2V  
(differential with respect to COM), C = 10pF at digital outputs (Note 1), f  
= 105.263MHz, T = T  
to  
IN  
P-P  
L
CLK  
A
MIN  
T
MAX  
, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)  
A
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
Operating, C = 15pF , f  
L
-0.5dBFS  
= 20MHz at  
INA or B  
15  
mA  
Output Supply Current  
I
OVDD  
Sleep mode  
100  
2
µA  
mW  
µW  
Shutdown, clock idle, PD = OE = OV  
10  
DD  
Operating, f  
Sleep mode  
= 20MHz at -0.5dBFS  
413  
9.2  
3
511  
INA or B  
Power Dissipation  
PDISS  
PSRR  
Shutdown, clock idle, PD = OE = OV  
50  
8
DD  
Offset  
Gain  
0.2  
0.1  
mV/V  
%/V  
Power-Supply Rejection Ratio  
TIMING CHARACTERISTICS  
CLK Rise to Output Data Valid  
t
Figure 3 (Note 5)  
Figure 4  
5
ns  
ns  
ns  
DO  
Output Enable Time  
Output Disable Time  
t
10  
1.5  
ENABLE  
t
Figure 4  
DISABLE  
4.75  
1.5  
CLK Pulse-Width High  
CLK Pulse-Width Low  
Wake-Up Time (Note 6)  
t
Figure 3, clock period: 9.5ns  
Figure 3, clock period: 9.5ns  
ns  
ns  
µs  
CH  
4.75  
1.5  
t
CL  
Wakeup from sleep mode  
Wakeup from shutdown  
0.18  
1.5  
t
WAKE  
CHANNEL-TO-CHANNEL MATCHING  
Crosstalk  
f
f
f
= 20MHz at -0.5dBFS  
= 20MHz at -0.5dBFS  
= 20MHz at -0.5dBFS  
-70  
dB  
dB  
INA or B  
INA or B  
INA or B  
Gain Matching  
0.02  
0.25  
0.2  
Phase Matching  
degrees  
Note 1: Equivalent dynamic performance is obtainable over full OV  
range with reduced C .  
L
DD  
Note 2: Specifications at +25°C are guaranteed by production test and < +25°C are guaranteed by design and characterization.  
Note 3: SNR, SINAD, THD, SFDR, and HD3 are based on an analog input voltage of -0.5dBFS, referenced to a 1.024V full-scale  
input voltage range.  
Note 4: Intermodulation distortion is the total power of the intermodulation products relative to the individual carrier. This number is  
6dB or better, if referenced to the two-tone envelope.  
Note 5: Digital outputs settle to V , V . Parameter guaranteed by design.  
IH IL  
Note 6: With REFIN driven externally, REFP, COM, and REFN are left floating while powered down.  
_______________________________________________________________________________________  
5
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Typical Operating Characteristics  
(V  
= 3.3V, OV  
= 2.5V, internal reference, differential input at -0.5dBFS, f  
= 105.0006MHz, C 10pF. T = +25°C, unless  
DD  
DD  
CLK L A  
otherwise noted.)  
FFT PLOT CHA (8192-POINT RECORD,  
DIFFERENTIAL INPUT)  
FFT PLOT CHB (8192-POINT RECORD,  
DIFFERENTIAL INPUT)  
FFT PLOT CHA (8192-POINT RECORD,  
DIFFERENTIAL INPUT)  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
CHA  
CHB  
CHA  
f
f
f
= 6.2421MHz  
= 7.52384MHz  
= 105.0006MHz  
f
f
f
= 6.2421MHz  
= 7.52384MHz  
= 105.0006MHz  
f
f
f
= 20.0849MHz  
= 25.0068MHz  
= 105.0006MHz  
INA  
INB  
CLK  
INA  
INB  
CLK  
INA  
INB  
CLK  
A
= -0.52dBFS  
A
= -0.48dBFS  
A
= -0.54dBFS  
INA  
INB  
INA  
0
10  
20  
30  
40  
50  
60  
0
10  
20  
30  
40  
50  
60  
0
10  
20  
30  
40  
50  
60  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
FFT PLOT CHB (8192-POINT RECORD,  
DIFFERENTIAL INPUT)  
FFT PLOT CHA (8192-POINT RECORD,  
DIFFERENTIAL INPUT)  
FFT PLOT CHB (8192-POINT RECORD,  
DIFFERENTIAL INPUT)  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
CHB  
CHA  
CHB  
f
f
f
= 52.2326MHz  
= 57.0504MHz  
= 105.0006MHz  
= -0.47dBFS  
f
f
f
= 52.2326MHz  
= 57.0505MHz  
= 105.0006MHz  
= -0.47dBFS  
f
f
f
= 20.0849MHz  
= 25.0068MHz  
= 105.0006MHz  
= -0.54dBFS  
INA  
INB  
CLK  
INA  
INB  
CLK  
INA  
INB  
CLK  
A
A
A
INB  
INA  
INA  
0
10  
20  
30  
40  
50  
60  
0
10  
20  
30  
40  
50  
60  
0
10  
20  
30  
40  
50  
60  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
TWO-TONE IMD PLOT (8192-POINT  
RECORD, DIFFERENTIAL INPUT)  
SIGNAL-TO-NOISE RATIO  
vs. ANALOG INPUT FREQUENCY  
SIGNAL-TO-NOISE AND DISTORTION  
vs. ANALOG INPUT FREQUENCY  
0
61  
60  
59  
58  
57  
56  
55  
62  
60  
58  
56  
54  
DIFFERENTIAL INPUT CONFIGURATION  
CHB  
f
f
f
= 38.0552MHz  
= 41.9259MHz  
= 105.0006MHz  
DIFFERENTIAL INPUT CONFIGURATION  
INA  
INB  
CLK  
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
A
= A = -6.5dBFS  
IN2  
IN1  
CHB  
CHA  
f
f
IN2  
IN1  
CHA  
IM2  
IM3  
IM3  
0
10  
20  
30  
40  
50  
60  
0
10 20 30 40 50 60 70 80 90 100  
ANALOG INPUT FREQUENCY (MHz)  
0
20  
40  
60  
80  
100  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
6
_______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Typical Operating Characteristics (continued)  
(V  
= 3.3V, OV  
= 2.5V, internal reference, differential input at -0.5dBFS, f  
= 105.0006MHz, C 10pF. T = +25°C, unless  
DD  
DD  
CLK L A  
otherwise noted.)  
TOTAL HARMONIC DISTORTION  
vs. ANALOG INPUT FREQUENCY  
SPURIOUS-FREE DYNAMIC RANGE  
vs. ANALOG INPUT FREQUENCY  
FULL-POWER INPUT BANDWIDTH vs.  
ANALOG INPUT FREQUENCY, SINGLE-ENDED  
-65  
-68  
-71  
-74  
87  
83  
79  
75  
71  
67  
63  
6
DIFFERENTIAL INPUT CONFIGURATION  
DIFFERENTIAL INPUT CONFIGURATION  
4
2
CHB  
CHB  
0
-2  
CHA  
CHA  
-4  
-6  
-8  
-77  
-80  
0
20  
40  
60  
80  
100  
0
20  
40  
60  
80  
100  
1
10  
100  
1000  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT FREQUENCY (MHz)  
SMALL-SIGNAL INPUT BANDWIDTH vs.  
ANALOG INPUT FREQUENCY, SINGLE-ENDED  
SIGNAL-TO-NOISE RATIO vs.  
SIGNAL-TO-NOISE AND DISTORTION vs.  
ANALOG INPUT POWER (f = 20.084947MHz)  
ANALOG INPUT POWER (f = 20.084947MHz)  
IN  
IN  
65  
65  
6
4
2
V
= 100mVp-p  
IN  
60  
55  
50  
45  
40  
35  
60  
55  
50  
45  
40  
35  
0
-2  
-4  
-6  
-8  
1
10  
100  
1000  
-20  
-16  
-12  
-8  
-4  
0
-20  
-16  
-12  
-8  
-4  
0
ANALOG INPUT FREQUENCY (MHz)  
ANALOG INPUT POWER (dBFS)  
ANALOG INPUT POWER (dBFS)  
TOTAL HARMONIC DISTORTION vs.  
ANALOG INPUT POWER (f = 20.0849474MHz)  
INTEGRAL NONLINEARITY  
(BEST ENDPOINT FIT)  
SPURIOUS-FREE DYNAMIC RANGE vs.  
ANALOG INPUT POWER (f = 20.0849474MHz)  
IN  
IN  
-55  
80  
76  
1.0  
0.5  
0
-60  
-65  
-70  
-75  
-80  
72  
68  
-0.5  
-1.0  
64  
60  
-20  
-16  
-12  
-8  
-4  
0
-20  
-16  
-12  
-8  
-4  
0
0
128 256 384 512 640 768 896 1024  
DIGITAL OUTPUT CODE  
ANALOG INPUT POWER (dBFS)  
ANALOG INPUT POWER (dBFS)  
_______________________________________________________________________________________  
7
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Typical Operating Characteristics (continued)  
(V  
DD  
= 3.3V, OV  
= 2.5V, internal reference, differential input at -0.5dBFS, f  
= 105.0006MHz, C 10pF. T = +25°C, unless  
DD  
CLK L A  
otherwise noted.)  
GAIN ERROR vs. TEMPERATURE,  
EXTERNAL REFERENCE (V  
= 2.048V)  
DIFFERENTIAL NONLINEARITY  
REFIN  
0.50  
0.25  
0
1.0  
0.5  
0
1.0  
0.5  
0
CHB  
CHA  
CHB  
-0.5  
-1.0  
-1.5  
-0.25  
-0.50  
CHA  
-0.5  
-1.0  
0
128 256 384 512 640 768 896 1024  
DIGITAL OUTPUT CODE  
-40  
-15  
10  
35  
60  
85  
-40  
-15  
10  
35  
60  
85  
TEMPERATURE (°C)  
TEMPERATURE (°C)  
ANALOG POWER-DOWN CURRENT  
vs. ANALOG POWER SUPPLY  
ANALOG SUPPLY CURRENT  
vs. ANALOG SUPPLY VOLTAGE  
ANALOG SUPPLY CURRENT  
vs. TEMPERATURE  
1.0  
0.8  
0.6  
0.4  
0.2  
0
150  
140  
130  
120  
110  
100  
150  
140  
130  
120  
110  
100  
OE = PD = OV  
DD  
2.70 2.85 3.00 3.15 3.30 3.45 3.60  
(V)  
2.70 2.85 3.00 3.15 3.30 3.45 3.60  
-40  
-15  
10  
35  
60  
85  
V
V
(V)  
TEMPERATURE (°C)  
DD  
DD  
INTERNAL REFERENCE VOLTAGE  
vs. ANALOG SUPPLY VOLTAGE  
SNR/SINAD, -THD/SFDR  
vs. CLOCK DUTY CYCLE  
2.050  
2.046  
2.042  
2.038  
2.034  
2.030  
90  
80  
70  
60  
50  
40  
f
f
= 20.0849MHz  
= 25.0069MHz  
INA  
INB  
SFDR  
-THD  
SNR  
SINAD  
52  
2.70 2.85 3.00 3.15 3.30 3.45 3.60  
(V)  
40  
44  
48  
56  
60  
V
CLOCK DUTY CYCLE (%)  
DD  
8
_______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Typical Operating Characteristics (continued)  
(V  
DD  
= 3.3V, OV  
= 2.5V, internal reference, differential input at -0.5dBFS, f  
= 105.0006MHz, C 10pF. T = +25°C, unless  
DD  
CLK L A  
otherwise noted.)  
INTERNAL REFERENCE VOLTAGE  
vs. TEMPERATURE  
OUTPUT NOISE HISTOGRAM (DC INPUT)  
2.065  
7000  
64676  
6000  
5000  
4000  
3000  
2000  
1000  
0
2.055  
2.045  
2.035  
2.025  
2.015  
0
607  
252  
0
-40  
-15  
10  
35  
60  
85  
N - 2  
N - 1  
N
N + 1  
N + 2  
TEMPERATURE (°C)  
DIGITAL OUTPUT NOISE  
Pin Description  
PIN  
NAME  
FUNCTION  
1
COM  
Common-Mode Voltage Input/Output. Bypass to GND with a 0.1µF capacitor.  
Analog Supply Voltage. Bypass each supply pin to GND with a 0.1µF capacitor. The analog  
supply accepts a 2.7V to 3.6V input range.  
2, 6, 11, 14, 15  
V
DD  
3, 7, 10, 13, 16  
GND  
INA+  
INA-  
INB-  
INB+  
CLK  
Analog Ground  
4
5
Channel A Positive Analog Input. For single-ended operation, connect signal source to INA+.  
Channel A Negative Analog Input. For single-ended operation, connect INA- to COM.  
Channel B Negative Analog Input. For single-ended operation, connect INB- to COM.  
Channel B Positive Analog Input. For single-ended operation, connect signal source to INB+.  
Converter Clock Input  
8
9
12  
T/B selects the ADC digital output format.  
High: Two’s complement.  
Low: Straight offset binary.  
17  
18  
19  
20  
T/B  
SLEEP  
PD  
Sleep Mode Input.  
High: Deactivates the two ADCs, but leaves the reference bias circuit active.  
Low: Normal operation.  
Power-Down Input.  
High: Power-down mode  
Low: Normal operation  
Output Enable Input.  
High: Digital outputs disabled  
Low: Digital outputs enabled  
OE  
_______________________________________________________________________________________  
9
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Pin Description (continued)  
PIN  
21  
NAME  
D9B  
D8B  
D7B  
D6B  
D5B  
D4B  
D3B  
D2B  
D1B  
D0B  
OGND  
FUNCTION  
Three-State Digital Output, Bit 9 (MSB), Channel B  
22  
Three-State Digital Output, Bit 8, Channel B  
Three-State Digital Output, Bit 7, Channel B  
Three-State Digital Output, Bit 6, Channel B  
Three-State Digital Output, Bit 5, Channel B  
Three-State Digital Output, Bit 4, Channel B  
Three-State Digital Output, Bit 3, Channel B  
Three-State Digital Output, Bit 2, Channel B  
Three-State Digital Output, Bit 1, Channel B  
Three-State Digital Output, Bit 0 (LSB), Channel B  
Output Driver Ground  
23  
24  
25  
26  
27  
28  
29  
30  
31, 34  
Output Driver Supply Voltage. Bypass each supply pin to OGND with a 0.1µF capacitor. The  
output driver supply accepts a 1.7V to 3.6V input range.  
32, 33  
OV  
DD  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
D0A  
D1A  
D2A  
D3A  
D4A  
D5A  
D6A  
D7A  
D8A  
D9A  
Three-State Digital Output, Bit 0 (LSB), Channel A  
Three-State Digital Output, Bit 1, Channel A  
Three-State Digital Output, Bit 2, Channel A  
Three-State Digital Output, Bit 3, Channel A  
Three-State Digital Output, Bit 4, Channel A  
Three-State Digital Output, Bit 5, Channel A  
Three-State Digital Output, Bit 6, Channel A  
Three-State Digital Output, Bit 7, Channel A  
Three-State Digital Output, Bit 8, Channel A  
Three-State Digital Output, Bit 9 (MSB), Channel A  
Internal Reference Voltage Output. May be connected to REFIN through a resistor or a resistor  
divider.  
45  
46  
47  
REFOUT  
REFIN  
REFP  
Reference Input. V  
= 2 (V  
- V  
).  
REFIN  
REFP  
REFN  
Bypass to GND with a > 1nF capacitor.  
Positive Reference Input/Output. Conversion range is (V  
Bypass to GND with a > 0.1µF capacitor.  
- V  
).  
REFP  
REFN  
Negative Reference Input/Output. Conversion range is (V  
Bypass to GND with a > 0.1µF capacitor.  
- V  
).  
REFP  
REFN  
48  
REFN  
EP  
Exposed Paddle. Connect to analog ground.  
10 ______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
V
V
IN  
V
V
OUT  
IN  
OUT  
x2  
x2  
Σ
Σ
T/H  
T/H  
FLASH  
ADC  
FLASH  
ADC  
DAC  
DAC  
1.5 BITS  
1.5 BITS  
2-BIT FLASH  
ADC  
2-BIT FLASH  
ADC  
STAGE 1  
STAGE 2  
STAGE 8  
STAGE 9  
STAGE 1  
STAGE 2  
STAGE 8  
STAGE 9  
DIGITAL CORRECTION LOGIC  
10  
DIGITAL CORRECTION LOGIC  
10  
T/H  
T/H  
D9A–D0A  
D9B–D0B  
V
V
INB  
INA  
V
V
= INPUT VOLTAGE BETWEEN INA+ AND INA- (DIFFERENTIAL OR SINGLE-ENDED)  
= INPUT VOLTAGE BETWEEN INB+ AND INB- (DIFFERENTIAL OR SINGLE-ENDED)  
INA  
INB  
Figure 1. Pipelined Architecture—Stage Blocks  
(C2a and C2b) through switches S4a and S4b. S2a and  
S2b set the common mode for the amplifier input, and  
open simultaneously with S1, sampling the input wave-  
form. Switches S4a and S4b are then opened before  
switches S3a and S3b, connect capacitors C1a and  
C1b to the output of the amplifier, and switch S4c is  
closed. The resulting differential voltages are held on  
capacitors C2a and C2b. The amplifiers are used to  
charge capacitors C1a and C1b to the same values  
originally held on C2a and C2b. These values are then  
presented to the first-stage quantizers and isolate the  
pipelines from the fast-changing inputs. The wide input  
bandwidth T/H amplifiers allow the MAX1180 to track-  
and-sample/hold analog inputs of high frequencies  
(> Nyquist). Both ADC inputs (INA+, INB+, INA-, and  
INB-) can be driven either differentially or single-ended.  
Match the impedance of INA+ and INA-, as well as  
INB+ and INB-, and set the common-mode voltage to  
Detailed Description  
The MAX1180 uses a nine-stage, fully-differential  
pipelined architecture (Figure 1), that allows for high-  
speed conversion while minimizing power consump-  
tion. Samples taken at the inputs move progressively  
through the pipeline stages every half clock cycle.  
Counting the delay through the output latch, the clock-  
cycle latency is five clock cycles.  
1.5-bit (two-comparator) flash ADCs convert the held-  
input voltages into a digital code. The digital-to-analog  
converters (DACs) convert the digitized results back  
into analog voltages, which are then subtracted from  
the original held-input signals. The resulting error sig-  
nals are then multiplied by two and the residues are  
passed along to the next pipeline stages where the  
process is repeated until the signals have been  
processed by all nine stages. Digital error correction  
compensates for ADC comparator offsets in each of  
these pipeline stages and ensures no missing codes.  
midsupply (V  
/ 2) for optimum performance.  
DD  
Analog Inputs and Reference  
Configurations  
The full-scale range of the MAX1180 is determined  
by the internally generated voltage difference  
Input Track-and-Hold (T/H) Circuits  
Figure 2 displays a simplified functional diagram of the  
input track-and-hold (T/H) circuits in both track-and-  
hold mode. In track mode, switches S1, S2a, S2b, S4a,  
S4b, S5a and S5b are closed. The fully-differential cir-  
cuits sample the input signals onto the two capacitors  
between REFP (V / 2 + V  
REFIN  
/ 4) and REFN (V / 2 -  
DD  
DD  
REFIN  
V
/ 4).The full-scale range for both on-chip  
______________________________________________________________________________________ 11  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
INTERNAL  
BIAS  
COM  
S5a  
S2a  
C1a  
S3a  
S4a  
S4b  
INA+  
INA-  
OUT  
OUT  
C2a  
C2b  
S4c  
S1  
C1b  
S3b  
S5b  
COM  
S2b  
INTERNAL  
BIAS  
CLK  
INTERNAL  
NONOVERLAPPING  
CLOCK SIGNALS  
HOLD  
HOLD  
INTERNAL  
BIAS  
TRACK  
TRACK  
COM  
S5a  
S2a  
C1a  
S3a  
S4a  
S4b  
INB+  
INB-  
OUT  
OUT  
C2a  
C2b  
S4c  
S1  
MAX1180  
C1b  
S3b  
S5b  
COM  
S2b  
INTERNAL  
BIAS  
Figure 2. MAX1180 T/H Amplifiers  
ADCs is adjustable through the REFIN pin, which is  
provided for this purpose.  
• Internal reference mode  
• Buffered external reference mode  
• Unbuffered external reference mode  
REFOUT, REFP, COM (V  
/ 2), and REFN are internal-  
DD  
ly buffered low-impedance outputs.  
In the internal reference mode, connect the internal ref-  
erence output REFOUT to REFIN through a resistor  
(e.g., 10k) or resistor divider, if an application requires  
The MAX1180 provides three modes of reference  
operation:  
12 ______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
5 CLOCK-CYCLE LATENCY  
N
N + 1  
N + 2  
N + 3  
N + 4  
N + 5  
N + 6  
ANALOG INPUT  
CLOCK INPUT  
t
CLK  
t
t
CH  
D0  
t
CL  
DATA OUTPUT  
D9A–D0A  
N - 6  
N - 6  
N - 5  
N - 4  
N - 4  
N - 3  
N - 3  
N - 2  
N - 1  
N - 1  
N
N
N + 1  
DATA OUTPUT  
D9B–D0B  
N - 5  
N - 2  
N + 1  
Figure 3. System Timing Diagram  
Table 1. MAX1180 Output Codes For Differential Inputs  
STRAIGHT OFFSET  
BINARY  
DIFFERENTIAL INPUT  
VOLTAGE*  
TWO’S COMPLEMENT  
T/B = 1  
DIFFERENTIAL INPUT  
T/B = 0  
V
511/512  
+FULL SCALE - 1LSB  
+ 1 LSB  
11 1111 1111  
10 0000 0001  
10 0000 0000  
01 1111 1111  
00 0000 0001  
00 0000 0000  
01 1111 1111  
00 0000 0001  
00 0000 0000  
11 1111 1111  
10 0000 0001  
10 0000 0000  
REF  
V
1/512  
REF  
0
Bipolar Zero  
-V  
1/512  
- 1 LSB  
REF  
-V  
511/512  
512/512  
-FULL SCALE + 1 LSB  
-FULL SCALE  
REF  
REF  
-V  
*V  
= V  
- V  
REFP REFN  
REF  
a reduced full-scale range. For stability and noise filtering  
purposes, bypass REFIN with a > 10nF capacitor to  
GND. In internal reference mode, REFOUT, COM, REFP,  
and REFN become low-impedance outputs.  
may be driven through separate external reference  
sources.  
Clock Input (CLK)  
The MAX1180’s CLK input accepts CMOS-compatible  
clock signals. Since the interstage conversion of the  
device depends on the repeatability of the rising and  
falling edges of the external clock, use a clock with low  
jitter and fast rise and fall times (< 2ns). In particular,  
sampling occurs on the rising edge of the clock signal,  
requiring this edge to provide lowest possible jitter. Any  
significant aperture jitter would limit the SNR perfor-  
mance of the on-chip ADCs as follows:  
In the buffered external reference mode, adjust the ref-  
erence voltage levels externally by applying a stable  
and accurate voltage at REFIN. In this mode, COM,  
REFP, and REFN become outputs. REFOUT may be left  
open or connected to REFIN through a > 10kresistor.  
In the unbuffered external reference mode, connect  
REFIN to GND. This deactivates the on-chip reference  
buffers for REFP, COM, and REFN. With their buffers  
shut down, these nodes become high impedance and  
SNR = 20 log (1 / [2π x f  
t
AJ  
]),  
10  
IN  
______________________________________________________________________________________ 13  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
where f represents the analog input frequency and  
AJ  
IN  
OE  
t
is the time of the aperture jitter.  
Clock jitter is especially critical for undersampling  
applications. The clock input should always be consid-  
ered as an analog input and routed away from any ana-  
log input or other digital signal lines.  
t
t
DISABLE  
ENABLE  
OUTPUT  
D9A–D0A  
HIGH-Z  
HIGH-Z  
HIGH-Z  
VALID DATA  
VALID DATA  
The MAX1180 clock input operates with a voltage thresh-  
old set to V  
/ 2. Clock inputs with a duty cycle other  
DD  
OUTPUT  
D9B–D0B  
HIGH-Z  
than 50%, must meet the specifications for high and low  
periods as stated in the Electrical Characteristics.  
Figure 4. Output Timing Diagram  
System Timing Requirements  
Figure 3 depicts the relationship between the clock  
input, analog input, and data output. The MAX1180  
samples at the rising edge of the input clock. Output  
data for channels A and B is valid on the next rising  
edge of the input clock. The output data has an internal  
latency of five clock cycles. Figure 4 also determines  
the relationship between the input clock parameters  
and the valid output data on channels A and B.  
To enter full power-down mode, pull PD high. With OE  
simultaneously low, all outputs are latched at the last  
value prior to the power-down. Pulling OE high, forces  
the digital outputs into a high-impedance state.  
Applications Information  
Figure 5 depicts a typical application circuit containing  
two single-ended to differential converters. The internal  
Digital Output Data, Output Data Format  
Selection (T/B), Output Enable (OE)  
reference provides a V  
/ 2 output voltage for level-  
DD  
shifting purposes. The input is buffered and then split to  
a voltage follower and inverter. One lowpass filter per  
ADC suppresses some of the wideband noise associat-  
ed with high-speed operational amplifiers. The user  
All digital outputs, D0A–D9A (Channel A) and D0B–D9B  
(Channel B), are TTL/CMOS logic-compatible. There is  
a five clock cycle latency between any particular sam-  
ple and its corresponding output data. The output cod-  
ing can be chosen to be either straight offset binary or  
two’s complement (Table 1) controlled by a single pin  
(T/B). Pull T/B low to select offset binary and high to  
activate two’s complement output coding. The capaci-  
tive load on the digital outputs D0A–D9A and D0B–D9B  
should be kept as low as possible (< 15pF), to avoid  
large digital currents that could feed back into the ana-  
log portion of the MAX1180, thereby degrading its  
dynamic performance. Using buffers on the digital out-  
puts of the ADCs can further isolate the digital outputs  
from heavy capacitive loads. To further improve the  
dynamic performance of the MAX1180 small-series  
resistors (e.g., 100), add to the digital output paths,  
close to the MAX1180.  
may select the R  
and C values to optimize the filter  
IN  
ISO  
performance to suit a particular application. For the  
application in Figure 5, a R of 50is placed before  
ISO  
the capacitive load to prevent ringing and oscillation.  
The 22pF C capacitor acts as a small bypassing  
IN  
capacitor.  
Using Transformer Coupling  
An RF transformer (Figure 6) provides an excellent  
solution to convert a single-ended source signal to a  
fully-differential signal, required by the MAX1180 for  
optimum performance. Connecting the center tap of the  
transformer to COM provides a V  
/ 2 DC level shift to  
DD  
the input. Although a 1:1 transformer is shown, a step-  
up transformer may be selected to reduce the drive  
requirements. A reduced signal swing from the input  
driver, such as an op amp, may also improve the over-  
all distortion.  
Figure 4 displays the timing relationship between out-  
put enable and data output valid, as well as power-  
down/wake-up and data output valid.  
In general, the MAX1180 provides better SFDR and  
THD with fully-differential input signals, than a single-  
ended drive, especially for high input frequencies. In  
differential input mode, even-order harmonics are lower  
as both inputs (INA+, INA- and/or INB+, INB-) are bal-  
anced, and each of the ADC inputs only require half the  
signal swing compared to single-ended mode.  
Power-Down (PD) and Sleep (SLEEP)  
Modes  
The MAX1180 offers two power-save modes, sleep and  
full power-down mode. In sleep mode (SLEEP = 1),  
only the reference bias circuit is active (both ADCs are  
disabled) and current consumption is reduced to  
2.8mA.  
14 ______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
+5V  
0.1µF  
LOWPASS FILTER  
INA+  
MAX4108  
R
50Ω  
ISO  
0.1µF  
300Ω  
C
IN  
22pF  
0.1µF  
-5V  
600Ω  
600Ω  
300Ω  
COM  
0.1µF  
+5V  
+5V  
0.1µF  
0.1µF  
600Ω  
INPUT  
0.1µF  
0.1µF  
LOWPASS FILTER  
MAX4108  
300Ω  
300Ω  
INA-  
MAX4108  
R
ISO  
C
IN  
22pF  
50Ω  
-5V  
-5V  
+5V  
300Ω  
300Ω  
600Ω  
MAX1180  
0.1µF  
LOWPASS FILTER  
INB+  
MAX4108  
R
50Ω  
ISO  
0.1µF  
300Ω  
C
IN  
22pF  
0.1µF  
600Ω  
-5V  
600Ω  
300Ω  
0.1µF  
+5V  
+5V  
0.1µF  
0.1µF  
600Ω  
INPUT  
0.1µF  
LOWPASS FILTER  
MAX4108  
300Ω  
300Ω  
INB-  
MAX4108  
R
ISO  
50Ω  
C
IN  
22pF  
-5V  
0.1µF  
600Ω  
-5V  
300Ω  
300Ω  
Figure 5. Typical Application for Single-Ended-to-Differential Conversion  
______________________________________________________________________________________ 15  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
quadrature (Q) carrier component, where the Q compo-  
25Ω  
nent is 90 degrees phase-shifted with respect to the in-  
INA+  
phase component. At the receiver, the QAM signal is  
22pF  
divided down into its I and Q components, essentially  
representing the modulation process reversed. Figure 8  
0.1µF  
1
2
6
5
4
displays the demodulation process performed in the  
analog domain, using the dual-matched, 3V, 10-bit  
ADCs, MAX1180 and the MAX2451 quadrature demod-  
ulators, to recover and digitize the I and Q baseband  
signals. Before being digitized by the MAX1180, the  
mixed-down signal components may be filtered by  
matched analog filters, such as Nyquist or Pulse-  
Shaping filters which remove any unwanted images  
from the mixing process, enhances the overall signal-  
to-noise (SNR) performance, and minimizes intersym-  
bol interference.  
T1  
V
IN  
N.C.  
COM  
2.2µF  
0.1µF  
3
MINI-CIRCUITS  
TT1–6  
25Ω  
INA-  
INB+  
22pF  
22pF  
MAX1180  
25Ω  
Grounding, Bypassing,  
and Board Layout  
0.1µF  
The MAX1180 requires high-speed board layout design  
techniques. Locate all bypass capacitors as close to  
the device as possible, preferably on the same side as  
the ADC, using surface-mount devices for minimum  
1
2
6
5
4
T1  
V
IN  
N.C.  
2.2µF  
0.1µF  
3
inductance. Bypass V , REFP, REFN, and COM with  
DD  
MINI-CIRCUITS  
TT1–6  
two parallel 0.1µF ceramic capacitors and a 2.2µF  
bipolar capacitor to GND. Follow the same rules to  
bypass the digital supply (OV ) to OGND. Multilayer  
DD  
25Ω  
INB-  
boards with separate ground and power planes, pro-  
duce the highest level of signal integrity. Consider the  
use of a split ground plane arranged to match the  
physical location of the analog ground (GND) and the  
digital output driver ground (OGND) on the ADCs pack-  
age. The two ground planes should be joined at a sin-  
gle point, such that the noisy digital ground currents do  
not interfere with the analog ground plane. The ideal  
location of this connection can be determined experi-  
mentally at a point along the gap between the two  
ground planes, which produces optimum results. Make  
this connection with a low-value, surface-mount resistor  
(1to 5), a ferrite bead, or a direct short.  
Alternatively, all ground pins could share the same  
ground plane, if the ground plane is sufficiently isolated  
from any noisy, digital systems ground plane (e.g.,  
downstream output buffer or DSP ground plane). Route  
high-speed digital signal traces away from the sensitive  
analog traces of either channel. Make sure to isolate  
the analog input lines to each respective converter to  
minimize channel-to-channel crosstalk. Keep all signal  
lines short and free of 90 degree turns.  
22pF  
Figure 6. Transformer-Coupled Input Drive  
Single-Ended AC-Coupled Input Signal  
Figure 7 shows an AC-coupled, single-ended applica-  
tion. Amplifiers, like the MAX4108, provide high-speed,  
high bandwidth, low-noise, and low distortion to main-  
tain the integrity of the input signal.  
Typical QAM Demodulation Application  
The most frequently used modulation technique for dig-  
ital communications application is the Quadrature  
Amplitude Modulation (QAM). QAMs are typically found  
in spread-spectrum based systems. A QAM signal rep-  
resents a carrier frequency modulated in both ampli-  
tude and phase. At the transmitter, modulating the  
baseband signal with quadrature outputs, a local oscil-  
lator followed by subsequent up-conversion can gener-  
ate the QAM signal. The result is an in-phase (I) and a  
16 ______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
REFP  
1kΩ  
1kΩ  
R
50Ω  
V
IN  
ISO  
0.1µF  
INA+  
COM  
INA-  
MAX4108  
C
22pF  
IN  
100Ω  
100Ω  
REFN  
0.1µF  
R
50Ω  
ISO  
C
IN  
22pF  
REFP  
MAX1180  
1kΩ  
R
50Ω  
ISO  
V
IN  
0.1µF  
INB+  
MAX4108  
C
IN  
100Ω  
100Ω  
1kΩ  
22pF  
REFN  
0.1µF  
R
ISO  
50Ω  
INB-  
C
IN  
22pF  
Figure 7. Using an Op Amp for Single-Ended, AC-Coupled Input Drive  
MAX2451  
INA+  
INA-  
0°  
90°  
DSP POST  
PROCESSING  
MAX1180  
INB+  
INB-  
DOWNCONVERTER  
÷
8
Figure 8. Typical QAM Application, Using the MAX1180  
______________________________________________________________________________________ 17  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
The ideal, theoretical minimum analog-to-digital noise is  
caused by quantization error only and results directly  
from the ADCs resolution (N-Bits):  
CLK  
SNR  
= 6.02 N + 1.76  
[max]  
In reality, there are other noise sources besides quanti-  
zation noise; thermal noise, reference noise, clock jitter,  
etc. SNR is computed by taking the ratio of the RMS  
signal to the RMS noise, which includes all spectral  
components minus the fundamental, the first five har-  
monics, and the DC offset.  
ANALOG  
INPUT  
t
AD  
t
AJ  
SAMPLED  
DATA (T/H)  
Signal-to-Noise Plus Distortion (SINAD)  
SINAD is computed by taking the ratio of the RMS sig-  
nal to all spectral components minus the fundamental  
and the DC offset.  
HOLD  
TRACK  
TRACK  
T/H  
Figure 9. T/H Aperture Timing  
Effective Number of Bits (ENOB)  
ENOB specifies the dynamic performance of an ADC at  
a specific input frequency and sampling rate. An ideal  
ADC’s error consists of quantization noise only. ENOB  
is computed from:  
Static Parameter Definitions  
Integral Nonlinearity (INL)  
Integral nonlinearity is the deviation of the values on an  
actual transfer function from a straight line. This straight  
line can be either a best straight-line fit or a line drawn  
between the endpoints of the transfer function, once  
offset and gain errors have been nullified. The static lin-  
earity parameters for the MAX1180 are measured using  
the best straight-line fit method.  
SINAD 1.76  
dB  
ENOB=  
6.02  
Total Harmonic Distortion (THD)  
THD is typically the ratio of the RMS sum of the first four  
harmonics of the input signal to the fundamental itself.  
This is expressed as:  
Differential Nonlinearity (DNL)  
Differential nonlinearity is the difference between an  
actual step-width and the ideal value of 1LSB. A DNL  
error specification of less than 1LSB guarantees no  
missing codes and a monotonic transfer function.  
2
2
2
2
V2 + V3 + V4 + V5  
THD = 20 × log  
10  
V
1
where V is the fundamental amplitude, and V through  
5
harmonics.  
1
2
Dynamic Parameter Definitions  
V
are the amplitudes of the 2nd- through 5th-order  
Aperture Jitter  
Figure 9 depicts the aperture jitter (t ), which is the  
AJ  
Spurious-Free Dynamic Range (SFDR)  
sample-to-sample variation in the aperture delay.  
SFDR is the ratio expressed in decibels of the RMS  
amplitude of the fundamental (maximum signal compo-  
nent) to the RMS value of the next largest spurious  
component, excluding DC offset.  
Aperture Delay  
Aperture delay (t ) is the time defined between the  
AD  
falling edge of the sampling clock and the instant when  
an actual sample is taken (Figure 9).  
Intermodulation Distortion (IMD)  
The two-tone IMD is the ratio expressed in decibels of  
either input tone to the worst 3rd-order (or higher) inter-  
modulation products. The individual input tone levels  
are at -6.5dB full scale.  
Signal-to-Noise Ratio (SNR)  
For a waveform perfectly reconstructed from digital  
samples, the theoretical maximum SNR is the ratio of  
the full-scale analog input (RMS value) to the RMS  
quantization error (residual error).  
18 ______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Functional Diagram  
V
OGND  
OV  
DD  
GND  
DD  
INA+  
10  
10  
OUTPUT  
DRIVERS  
PIPELINE  
ADC  
D9A–D0A  
DEC  
T/H  
INA-  
CLK  
CONTROL  
OE  
INB+  
INB-  
10  
10  
PIPELINE  
ADC  
OUTPUT  
DRIVERS  
DEC  
T/H  
D9B–D0B  
T/B  
REFERENCE  
PD  
MAX1180  
SLEEP  
REFOUT  
REFN COM REFP  
REFIN  
______________________________________________________________________________________ 19  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Package Information  
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,  
go to www.maxim-ic.com/packages.)  
PACKAGE OUTLINE,  
48L TQFP, 7x7x1.0mm EP OPTION  
1
21-0065  
G
2
20 ______________________________________________________________________________________  
Dual 10-Bit, 105Msps, 3.3V, Low-Power ADC  
with Internal Reference and Parallel Outputs  
Package Information (continued)  
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,  
go to www.maxim-ic.com/packages.)  
PACKAGE OUTLINE,  
48L TQFP, 7x7x1.0mm EP OPTION  
2
21-0065  
G
2
Revision History  
Pages changed at Rev 1: 1–20  
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are  
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.  
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 21  
© 2007 Maxim Integrated Products  
is a registered trademark of Maxim Integrated Products, Inc.  

相关型号:

MAX1180ECM+TD

ADC, Flash Method, 10-Bit, 1 Func, 2 Channel, Parallel, Word Access, PQFP48, 7 X 7 MM, 1 MM HEIGHT, ROHS COMPLIANT, MS-026ABA-HD, TQFP-48
MAXIM

MAX1180ECM-D

ADC, Flash Method, 10-Bit, 1 Func, 2 Channel, Parallel, Word Access, PQFP48, 7 X 7 MM, 1 MM HEIGHT, MS-026ABA-HD, TQFP-48
MAXIM

MAX1180ECM-T

ADC, Flash Method, 10-Bit, 1 Func, 2 Channel, Parallel, Word Access, CMOS, PQFP48, 7 X 7 MM, 1 MM HEIGHT, MS-026ABA-HD, TQFP-48
MAXIM

MAX1180ECM-TD

暂无描述
MAXIM

MAX1181

Dual 10-Bit.80Msps.+3V.Low-Power ADC with Internal Reference and Parallel Outputs
MAXIM

MAX11810ETP+

Micro Peripheral IC
MAXIM

MAX11810EWE+

Micro Peripheral IC
MAXIM

MAX11811

TacTouch™, Low-Power, Ultra-Small, Resistive Touch-Screen Controller with Haptic Driver
MAXIM

MAX11811TEVS

Pseudo Multi-Touch Demonstration
MAXIM

MAX11811TEVS+

Touch Evaluation System (TEVS)
MAXIM

MAX11811_1009

Touch Evaluation System (TEVS)
MAXIM

MAX1181ECM

Dual 10-Bit, 80Msps, 3V, Low-Power ADC with Internal Reference and Parallel Outputs
MAXIM