LTC2202UK [Linear]

16-Bit, 25Msps/10Msps ADCs; 16位, 25Msps时/ 10MSPS模数转换器
LTC2202UK
型号: LTC2202UK
厂家: Linear    Linear
描述:

16-Bit, 25Msps/10Msps ADCs
16位, 25Msps时/ 10MSPS模数转换器

转换器 模数转换器
文件: 总32页 (文件大小:1646K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
LTC2203/LTC2202  
16-Bit, 25Msps/10Msps ADCs  
U
FEATURES  
DESCRIPTIO  
The LTC®2203/LTC2202 are 25Msps/10Msps, sampling  
16-bitA/Dconvertersdesignedfordigitizinghighfrequen-  
cy, wide dynamic range signals with input frequencies up  
to 380MHz. The input range of the ADC can be optimized  
with the PGA front end.  
Sample Rate: 25Msps/10Msps  
81.6dB SNR and 100dB SFDR (2.5V Range)  
SFDR 90dB at 70MHz (1.667V Input Range)  
P-P  
PGA Front End (2.5V or 1.667V Input Range)  
P-P  
P-P  
380MHz Full Power Bandwidth S/H  
Optional Internal Dither  
Optional Data Output Randomizer  
Single 3.3V Supply  
The LTC2203/LTC2202 are perfect for demanding ap-  
plications, with AC performance that includes 81.6dB  
SNR and 100dB spurious free dynamic range (SFDR).  
Maximum DC specs include ±±LSB ꢀNL, ±1LSB DNL (no  
missing codes).  
Power Dissipation: 220mW/1±0mW  
Clock Duty Cycle Stabilizer  
Out-of-Range ꢀndicator  
A separate output power supply allows the CMOS output  
swing to range from 0.5V to 3.6V.  
Pin Compatible Family  
25Msps: LTC2203 (16-Bit)  
10Msps: LTC2202 (16-Bit)  
±8-Pin (7mm × 7mm) QFN Package  
Asingle-endedCLKinputcontrolsconverteroperation.An  
optionalclockdutycyclestabilizerallowshighperformance  
at full speed with a wide range of clock duty cycles.  
U
APPLICATIO S  
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All  
other trademarks are the property of their respective owners. Protected by U.S. Patents  
including ±8±3302 and 69±9965B1  
Telecommunications  
Receivers  
Cellular Base Stations  
Spectrum Analysis  
ꢀmaging Systems  
ATE  
U
TYPICAL APPLICATIO  
LTC2203: 128K Point FFT,  
fIN = 5.1MHz, –1dBFS, PGA = 0  
3.3V  
0
–10  
–20  
–30  
–±0  
SENSE  
OV  
DD  
1.25V  
COMMON MODE  
BꢀAS VOLTAGE  
ꢀNTERNAL ADC  
REFERENCE  
GENERATOR  
V
0.5V TO 3.6V  
CM  
1μF  
2.2μF  
–50  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
OF  
CLKOUT+  
CLKOUT–  
+
A
ꢀN  
+
16-BꢀT  
PꢀPELꢀNED  
ADC CORE  
OUTPUT  
DRꢀVERS  
CORRECTꢀON  
LOGꢀC AND  
SHꢀFT REGꢀSTER  
ANALOG  
ꢀNPUT  
S/H  
AMP  
CMOS  
OUTPUTS  
D15  
A
ꢀN  
D0  
OGND  
CLOCK/DUTY  
CYCLE  
CONTROL  
3.3V  
1μF  
V
DD  
1μF  
1μF  
GND  
0
2
±
6
8
10  
12  
FREQUENCY(MHz)  
22032 GO7  
CLK  
PGA SHDN DꢀTH MODE  
ADC CONTROL ꢀNPUTS  
RAND  
OE  
22032 TA01  
22032fb  
1
LTC2203/LTC2202  
W W U W  
U
W
U
ABSOLUTE AXI U RATI GS  
PACKAGE/ORDER I FOR ATIO  
OVDD = VDD (Notes 1 and 2)  
TOP VꢀEW  
Supply Voltage (V )...................................0.3V to ±V  
DD  
Digital Output Supply Voltage (OV )..........0.3V to ±V  
DD  
Digital Output Ground Voltage (OGND)........0.3V to 1V  
SENSE 1  
36 OV  
DD  
Analog ꢀnput Voltage (Note 3) ..... 0.3V to (V + 0.3V)  
DD  
V
V
V
2
3
±
35 D11  
3± D10  
33 D9  
CM  
Digital ꢀnput Voltage .................... 0.3V to (V + 0.3V)  
DD  
DD  
DD  
Digital Output Voltage................0.3V to (OV + 0.3V)  
DD  
GND 5  
32 D8  
+
Power Dissipation............................................ 2000mW  
A
A
6
7
31 OGND  
30 CLKOUT+  
29 CLKOUT–  
28 D7  
27 D6  
26 D5  
ꢀN  
±9  
ꢀN  
Operating Temperature Range  
GND 8  
GND 9  
CLK 10  
GND 11  
LTC2203C/LTC2202C............................... 0°C to 70°C  
LTC2203ꢀ/LTC2202.............................±0°C to 85°C  
Storage Temperature Range ..................65°C to 125°C  
V
DD  
12  
25 OV  
DD  
UK PACKAGE  
±8-LEAD (7mm × 7mm) PLASTꢀC QFN  
EXPOSED PAD ꢀS GND (PꢀN ±9)  
MUST BE SOLDERED TO PCB BOARD  
T
JMAX  
= 125°C, θ = 29°C/W  
JA  
T
= 150°C, OPTꢀON AVAꢀLABLE, CONSULT FACTORY  
JMAX  
ORDER PART  
NUMBER  
UK PART*  
MARKꢀNG  
LTC2203CUK  
LTC2202CUK  
LTC2203UK  
LTC2202UK  
LTC2203UK  
LTC2202UK  
LTC2203ꢀUK  
LTC2202ꢀUK  
Order Options Tape and Reel: Add #TR  
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF  
Lead Free Part Marking: http://www.linear.com/leadfree/  
*The temperature grade is identified by a label on the shipping container.  
Consult LTC Marketing for parts specified with wider operating temperature ranges.  
U
CO VERTER CHARACTERISTICS  
The denotes the specifications which apply over the full operating  
temperature range, otherwise specifications are at TA = 25°C. (Note 4)  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
Resolution (No missing codes)  
Integral Linearity Error  
Integral Linearity Error  
Differential Linearity Error  
Offset Error  
16  
Differential Analog Input (Note 5) T = 25°C  
±1ꢀ2  
±1ꢀ5  
±0ꢀ3  
±2  
±±ꢀ0  
±±ꢀ5  
±1  
LSB  
LSB  
A
Differential Analog Input (Note 5)  
Differential Analog Input  
(Note 6)  
LSB  
±10  
mV  
Offset Drift  
±10  
±0ꢀ2  
μV/°C  
%FS  
Gain Error  
External Reference  
±1ꢀ5  
Full-Scale Drift  
Internal Reference  
External Reference  
±30  
±15  
ppm/°C  
ppm/°C  
Transition Noise  
External Reference (2ꢀ5V Range, PGA = 0)  
1ꢀ92  
LSB  
RMS  
22032fb  
2
LTC2203/LTC2202  
U
U
A ALOG I PUT The denotes the specifications which apply over the full operating temperature range, otherwise  
specifications are at TA = 25°C. (Note 4)  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
TYP  
1ꢀ667 or 2ꢀ5  
1ꢀ25  
MAX  
UNITS  
+
V
IN  
Analog Input Range (A  
Analog Input Common Mode  
A
IN  
)
3ꢀ135V ≤ V ≤ 3ꢀ±65V  
V
P-P  
IN  
DD  
V
I
Differential Input (Note 7)  
1
–1  
–3  
1ꢀ5  
1
3
V
μA  
μA  
μA  
μA  
IN, CM  
+
Analog Input Leakage Current  
SENSE Input Leakage Current  
MODE Pin Pull-Down Current to GND  
OE Pin Pull-Down Current to GND  
Analog Input Capacitance  
0V ≤ A  
,
A
IN  
≤ V (Note 9)  
IN  
IN  
DD  
I
I
I
0V ≤ SENSE ≤ V (Note 10)  
SENSE  
MODE  
OE  
DD  
10  
10  
10ꢀ5  
1ꢀ±  
C
IN  
Sample Mode CLK = 0  
Hold Mode CLK = 0  
pF  
pF  
t
t
Sample-and-Hold  
0ꢀ9  
200  
80  
ns  
fs RMS  
dB  
AP  
Acquisition Delay Time  
Sample-and-Hold  
Acquisition Delay Time Jitter  
Analog Input  
Common Mode Rejection Ratio  
JITTER  
+
CMRR  
1V < (A = A ) <1ꢀ5V  
IN  
IN  
Rs < 20Ω  
380  
MHz  
BW-3dB U W Full Power Bandwidth  
DY A IC ACCURACY  
The denotes the specifications which apply over the full operating temperature range,  
otherwise specifications are at TA = 25°C. AIN = 1dBFS. (Note 4)  
LTC2203  
TYP  
LTC2202  
TYP  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
MAX  
MIN  
MAX  
UNITS  
SNR  
Signal-to-Noise Ratio  
1MHz Input (2ꢀ5V Range, PGA = 0)  
1MHz Input (1ꢀ667V Range, PGA = 1)  
81ꢀ6  
79ꢀ±  
81ꢀ6  
79ꢀ±  
dBFS  
dBFS  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (1ꢀ667V Range, PGA = 1)  
12ꢀ5MHz Input (2ꢀ5V Range, PGA = 0)  
12ꢀ5MHz Input (1ꢀ667V Range, PGA = 1)  
30MHz Input (2ꢀ5V Range, PGA = 0)  
30MHz Input (1ꢀ667V Range, PGA = 1)  
80ꢀ0  
81ꢀ6  
79ꢀ±  
81ꢀ±  
79ꢀ3  
80ꢀ8  
78ꢀ9  
80ꢀ0  
81ꢀ6  
79ꢀ±  
81ꢀ±  
79ꢀ3  
80ꢀ8  
78ꢀ9  
dBFS  
dBFS  
dBFS  
dBFS  
dBFS  
dBFS  
77ꢀ5  
77ꢀ5  
70MHz Input (2ꢀ5V Range, PGA = 0)  
70MHz Input (1ꢀ667V Range, PGA =1 )  
78ꢀ3  
77ꢀ2  
78ꢀ3  
77ꢀ2  
dBFS  
dBFS  
SFDR  
Spurious Free  
1MHz Input (2ꢀ5V Range, PGA = 0)  
1MHz Input (1ꢀ667V Range, PGA = 1)  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (1ꢀ667V Range, PGA = 1)  
12ꢀ5MHz Input (2ꢀ5V Range, PGA = 0)  
12ꢀ5MHz Input (1ꢀ667V Range, PGA = 1)  
30MHz Input (2ꢀ5V Range, PGA = 0)  
30MHz Input (1ꢀ667V Range, PGA = 1)  
100  
100  
100  
100  
100  
95  
100  
90  
95  
100  
100  
100  
100  
100  
95  
100  
90  
95  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
Dynamic Range  
nd  
rd  
2
or 3 Harmonic  
85  
90  
85  
90  
85  
85  
70MHz Input (2ꢀ5V Range, PGA = 0)  
70MHz Input (1ꢀ667V Range, PGA = 1)  
85  
90  
85  
90  
dBc  
dBc  
SFDR  
Spurious Free  
Dynamic Range  
th  
1MHz Input (2ꢀ5V Range, PGA = 0)  
1MHz Input (1ꢀ667V Range, PGA = 1)  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (1ꢀ667V Range, PGA = 1)  
12ꢀ5MHz Input (2ꢀ5V Range, PGA = 0)  
12ꢀ5MHz Input (1ꢀ667V Range, PGA = 1)  
30MHz Input (2ꢀ5V Range, PGA = 0)  
30MHz Input (1ꢀ667V Range, PGA = 1)  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
100  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
±
Harmonic  
90  
90  
90  
90  
or Higher  
70MHz Input (2ꢀ5V Range, PGA = 0)  
70MHz Input (1ꢀ667V Range, PGA = 1)  
90  
90  
90  
90  
dBc  
dBc  
22032fb  
3
LTC2203/LTC2202  
U W  
DY A IC ACCURACY  
The denotes the specifications which apply over the full operating temperature range,  
otherwise specifications are at TA = 25°C. AIN = –1dBFS unless otherwise noted. (Note 4)  
LTC2203  
LTC2202  
TYP  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
MIN  
MAX  
UNITS  
S/(N+D)  
Signal-to-Noise  
Plus Distortion Ratio  
1MHz Input (2ꢀ5V Range, PGA = 0)  
1MHz Input (1ꢀ667V Range, PGA = 1)  
81ꢀ5  
79ꢀ3  
81ꢀ5  
79ꢀ3  
dBFS  
dBFS  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (1ꢀ667V Range, PGA = 1)  
79ꢀ7  
81ꢀ5  
79ꢀ3  
79ꢀ7  
81ꢀ5  
79ꢀ3  
dBFS  
dBFS  
12ꢀ5MHz Input (2ꢀ5V Range, PGA = 0)  
12ꢀ5MHz Input (1ꢀ667V Range, PGA = 1)  
81ꢀ3  
79ꢀ2  
81ꢀ3  
79ꢀ2  
dBFS  
dBFS  
30MHz Input (2ꢀ5V Range, PGA = 0)  
30MHz Input (1ꢀ667V Range, PGA = 1)  
80ꢀ6  
78ꢀ6  
80ꢀ6  
78ꢀ6  
dBFS  
dBFS  
77ꢀ2  
77ꢀ2  
70MHz Input (2ꢀ5V Range, PGA = 0)  
70MHz Input (1ꢀ667V Range, PGA = 1)  
78ꢀ1  
77  
78ꢀ1  
77  
dBFS  
dBFS  
SFDR  
1MHz Input (2ꢀ5V Range, PGA = 0)  
1MHz Input (1ꢀ667V Range, PGA = 1)  
105  
105  
105  
105  
dBFS  
dBFS  
Spurious Free  
Dynamic Range  
at 25dBFS  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (1ꢀ667V Range, PGA = 1)  
105  
105  
105  
105  
dBFS  
dBFS  
Dither “OFF”  
12ꢀ5MHz Input (2ꢀ5V Range, PGA = 0)  
12ꢀ5MHz Input (1ꢀ667V Range, PGA = 1)  
105  
105  
105  
105  
dBFS  
dBFS  
30MHz Input (2ꢀ5V Range, PGA = 0)  
30MHz Input (1ꢀ667V Range, PGA = 1)  
105  
105  
105  
105  
dBFS  
dBFS  
70MHz Input (2ꢀ5V Range, PGA = 0)  
70MHz Input (1ꢀ667V Range, PGA = 1)  
100  
100  
100  
100  
dBFS  
dBFS  
SFDR  
1MHz Input (2ꢀ5V Range, PGA = 0)  
1MHz Input (1ꢀ667V Range, PGA = 1)  
115  
115  
115  
115  
dBFS  
dBFS  
Spurious Free  
Dynamic Range  
at 25dBFS  
5MHz Input (2ꢀ5V Range, PGA = 0)  
5MHz Input (1ꢀ667V Range, PGA = 1)  
100  
115  
115  
100  
115  
115  
dBFS  
dBFS  
Dither “ON”  
12ꢀ5MHz Input (2ꢀ5V Range, PGA = 0)  
12ꢀ5MHz Input (1ꢀ667V Range, PGA = 1)  
115  
115  
115  
115  
dBFS  
dBFS  
30MHz Input (2ꢀ5V Range, PGA = 0)  
30MHz Input (1ꢀ667V Range, PGA = 1)  
115  
115  
115  
115  
dBFS  
dBFS  
70MHz Input (2ꢀ5V Range, PGA = 0)  
70MHz Input (1ꢀ667V Range, PGA = 1)  
110  
110  
110  
110  
dBFS  
dBFS  
U U U U U U U  
the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 4)  
The denotes the specifications which apply over  
CO  
O ODE BIAS CHARACTERISTICS  
PARAMETER  
CONDITIONS  
MIN  
TYP  
1ꢀ25  
±±0  
1
MAX  
UNITS  
V
V
CM  
V
CM  
V
CM  
V
CM  
Output Voltage  
Output Tempco  
Line Regulation  
Output Resistance  
I
I
= 0  
= 0  
1ꢀ15  
1ꢀ35  
OUT  
OUT  
ppm/°C  
mV/V  
Ω
3ꢀ135V ≤ V ≤ 3ꢀ±65V  
DD  
1mA ≤ | I  
| ≤ 1mA  
2
OUT  
22032fb  
4
LTC2203/LTC2202  
U
U
DIGITAL I PUTS A D DIGITAL OUTPUTS  
The denotes the specifications which apply over the  
full operating temperature range, otherwise specifications are at TA = 25°C. (Note 4)  
SYMBOL PARAMETER CONDITIONS  
LOGIC INPUTS (CLK, OE, DITH, PGA, SHDN, RAND)  
MIN  
TYP  
MAX  
UNITS  
V
V
High Level Input Voltage  
Low Level Input Voltage  
Digital Input Current  
V
V
V
= 3ꢀ3V  
= 3ꢀ3V  
2
V
V
IH  
IL  
DD  
DD  
IN  
0ꢀ8  
I
IN  
= 0V to V  
±10  
μA  
pF  
DD  
C
IN  
Digital Input Capacitance  
(Note 7)  
1ꢀ5  
LOGIC OUTPUTS  
OV = 3.3V  
DD  
V
High Level Output Voltage  
Low Level Output Voltage  
V
V
= 3ꢀ3V  
= 3ꢀ3V  
I = –10μA  
I = 200μA  
O
3ꢀ299  
3ꢀ29  
V
V
OH  
DD  
DD  
O
3ꢀ1  
V
I = 160μA  
0ꢀ01  
0ꢀ10  
V
V
OL  
O
I = 1ꢀ6mA  
O
0ꢀ±  
I
I
Output Source Current  
Output Sink Current  
V
V
= 0V  
50  
50  
mA  
mA  
SOURCE  
OUT  
OUT  
= 3ꢀ3V  
SINK  
OV = 2.5V  
DD  
V
V
High Level Output Voltage  
Low Level Output Voltage  
V
V
= 3ꢀ3V  
= 3ꢀ3V  
I = 200μA  
2ꢀ±9  
0ꢀ1  
V
V
OH  
OL  
DD  
DD  
O
I = 1ꢀ60mA  
O
OV = 1.8V  
DD  
V
V
High Level Output Voltage  
Low Level Output Voltage  
V
V
= 3ꢀ3V  
= 3ꢀ3V  
I = 200μA  
1ꢀ79  
0ꢀ1  
V
V
OH  
DD  
DD  
O
I = 1ꢀ60mA  
O
OL  
W U  
POWER REQUIRE E TS  
The denotes the specifications which apply over the full operating temperature  
range, otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 4)  
LTC2203  
TYP  
LTC2202  
TYP  
SYMBOL  
PARAMETER  
CONDITIONS  
SHDN = V , CLK = V  
DD  
MIN  
MAX  
MIN  
MAX  
UNITS  
V
V
P
Analog Supply Voltage  
Shutdown Power  
3ꢀ135  
3ꢀ3  
2
3ꢀ±65  
3ꢀ135  
3ꢀ3  
2
3ꢀ±65  
DD  
mW  
V
SHDN  
DD  
OV  
Output Supply Voltage  
Analog Supply Current  
Power Dissipation  
0ꢀ5  
3ꢀ6  
80  
0ꢀ5  
3ꢀ6  
50  
DD  
I
66  
±2  
mA  
mW  
VDD  
P
220  
26±  
1±0  
165  
DIS  
22032fb  
5
LTC2203/LTC2202  
W U  
TI I G CHARACTERISTICS  
The denotes the specifications which apply over the full operating temperature  
range, otherwise specifications are at TA = 25°C. (Note 4)  
LTC2203  
TYP  
LTC2202  
TYP  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
MAX  
MIN  
MAX  
UNITS  
f
S
t
L
Sampling Frequency  
CLK Low Time  
1
25  
1
10  
MHz  
Duty Cycle Stabilizer Off  
Duty Cycle Stabilizer On  
18ꢀ9  
5
20  
20  
500  
500  
±0  
5
50  
50  
500  
500  
ns  
ns  
t
t
CLK High Time  
Duty Cycle Stabilizer Off  
Duty Cycle Stabilizer On  
18ꢀ9  
5
20  
20  
500  
500  
±0  
5
50  
50  
500  
500  
ns  
ns  
H
Sample-and-Hold  
Aperture Delay  
0ꢀ9  
0ꢀ9  
ns  
AP  
t
t
t
CLK to DATA Delay  
C = 5pF (Note 7)  
1ꢀ3  
1ꢀ3  
3ꢀ1  
3ꢀ1  
0
±ꢀ9  
±ꢀ9  
0ꢀ6  
1ꢀ3  
1ꢀ3  
3ꢀ1  
3ꢀ1  
0
±ꢀ9  
±ꢀ9  
0ꢀ6  
ns  
ns  
ns  
D
L
CLK to CLKOUT Delay  
C = 5pF (Note 7)  
L
C
DATA to CLKOUT Skew C = 5pF (Note 7)  
0ꢀ6  
0ꢀ6  
SKEW  
L
DATA Access Time  
Bus Relinquish Time  
C = 5pF (Note 7)  
(Note 7)  
5
5
15  
15  
5
5
15  
15  
ns  
ns  
L
Pipeline  
Latency  
7
7
Cycles  
Note 1: Stresses beyond those listed under Absolute Maximum Ratings  
may cause permanent damage to the device. Exposure to any Absolute  
Maximum Rating condition for extended periods may affect device  
reliability and lifetime.  
Note 2: All voltage values are with respect to GND, with GND and OGND  
shorted (unless otherwise noted).  
Note 5: ꢀntegral nonlinearity is defined as the deviation of a code from a  
“best fit straight line” to the transfer curve. The deviation is measured from  
the center of the quantization band.  
Note 6: Offset error is the offset voltage measured from 1/2LSB when the  
output code flickers between 0000 0000 0000 0000 and 1111 1111 1111  
1111 in 2’s complement output mode.  
Note 3: When these pin voltages are taken below GND or above V , they  
will be clamped by internal diodes. This product can handle input currents  
Note 7: Guaranteed by design, not subject to test.  
Note 8: Recommended operating conditions.  
Note 9: Dynamic current from switched capacitor inputs is large compared  
to DC leakage current, and will vary with sample rate.  
Note 10: Leakage current will experience transient at power up. Keep  
resistance < 1K Ω.  
DD  
of greater than 100mA below GND or above V without latchup.  
DD  
Note 4: V = 3.3V, f  
= 25MHz (LTC2203), 10MHz (LTC2202),  
DD  
SAMPLE  
input range = 2.5V with differential drive (PGA = 0), unless otherwise  
P-P  
specified.  
W U  
W
TI I G DIAGRA  
t
AP  
N + 1  
N + ±  
ANALOG  
ꢀNPUT  
N + 3  
N
N + 2  
t
L
t
H
CLK  
t
D
N – 7  
N – 6  
N – 5  
N – ±  
N – 3  
D0-D15, OF  
t
C
CLKOUT+  
CLKOUT–  
22032 TD01  
22032fb  
6
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2203: Integral Nonlinearity  
(INL) vs Output Code  
LTC2203: Differential Nonlinearity  
(DNL) vs Output Code  
LTC2203: AC Grounded Input  
Histogram (256k Samples)  
60000  
1.0  
0.8  
2.0  
1.5  
50000  
0.6  
1.0  
0.±  
±0000  
30000  
0.5  
0.2  
0.0  
0.0  
–0.2  
–0.±  
–0.6  
–0.8  
–1.0  
–0.5  
–1.0  
–1.5  
–2.0  
20000  
10000  
0
32768  
CODE  
0
1638±  
32768  
CODE  
65536  
0
1638±  
±9152  
65536  
±9152  
32812 32816 32820 3282± 32828 32832  
OUTPUT CODE  
22032 G01  
22032 G02  
22032 G03  
LTC2203: 128K Point FFT,  
fIN = 1MHz, –1dBFS, PGA = 0  
LTC2203: 128K Point FFT,  
fIN = 1MHz, –10dBFS, PGA = 0  
LTC2203: 128K Point FFT,  
fIN = 1MHz, –20dBFS, PGA = 0  
0
–10  
0
–10  
0
–10  
–20  
–20  
–20  
–30  
–30  
–30  
–±0  
–±0  
–±0  
–50  
–50  
–50  
–60  
–60  
–60  
–70  
–70  
–70  
–80  
–80  
–80  
–90  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 GO±  
22032 GO5  
22032 GO6  
LTC2203: 128K Point FFT,  
fIN = 5.1MHz, –20dBFS, PGA = 0,  
Internal Dither “Off”  
LTC2203: 128K Point FFT,  
fIN = 5.1MHz, –1dBFS, PGA = 0  
LTC2203: 128K Point FFT,  
fIN = 5.1MHz, –10dBFS, PGA = 0  
0
–10  
0
–10  
0
–10  
–20  
–20  
–20  
–30  
–30  
–30  
–±0  
–±0  
–±0  
–50  
–50  
–50  
–60  
–60  
–60  
–70  
–70  
–70  
–80  
–80  
–80  
–90  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
2
±
6
8
10  
12  
8
8
0
2
±
6
10  
12  
0
2
±
6
10  
12  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 GO7  
22032 GO8  
22032 GO9  
22032fb  
7
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2203: 128K Point FFT,  
fIN = 5.1MHz, –20dBFS, PGA = 0,  
Internal Dither “On”  
LTC2203: 32K Point 2-Tone FFT,  
fIN = 4.9MHz and 30.1MHz,  
–7dBFS, PGA = 0  
LTC2203: 32K Point 2-Tone FFT,  
fIN = 4.9MHz and 30.1MHz,  
–15dBFS, PGA = 0  
0
–10  
0
–10  
0
–10  
–20  
–20  
–20  
–30  
–30  
–30  
–±0  
–±0  
–±0  
–50  
–50  
–50  
–60  
–60  
–60  
–70  
–70  
–70  
–80  
–80  
–80  
–90  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 G12  
22032 G10  
22032 G11  
LTC2203: SFDR vs Input Level,  
fIN = 5MHz, PGA = 0, Dither “Off”  
LTC2203: SFDR vs Input Level,  
fIN = 5MHz, PGA = 0, Dither “On”  
LTC2203: 32K Point FFT,  
fIN = 12.4MHz, –1dBFS, PGA = 0  
1±0  
120  
1±0  
120  
0
–10  
–20  
–30  
–±0  
100  
100  
–50  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
80  
60  
±0  
20  
80  
60  
±0  
20  
0
0
–60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
–60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
–70  
–70  
0
2
±
6
8
10  
12  
FREQUENCY(MHz)  
22032 G15  
22032 G13  
22032 G1±  
LTC2203: SFDR vs Input Level,  
fIN = 12.7MHz, PGA = 0,  
Dither “Off”  
LTC2203: 32K Point FFT,  
fIN = 12.4MHz, –10dBFS, PGA = 0  
LTC2203: 32K Point FFT,  
fIN = 12.4MHz, –20dBFS, PGA = 0  
0
–10  
–20  
0
–10  
–20  
1±0  
120  
–30  
–30  
–±0  
–50  
–±0  
–50  
100  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
80  
60  
±0  
20  
0
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 G16  
22032 G17  
22032 G18  
22032fb  
8
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2203: SFDR vs Input Level,  
fIN = 12.7MHz, PGA = 0,  
Dither “On”  
LTC2203: 32K Point FFT,  
fIN = 30MHz, –1dBFS, PGA = 1  
LTC2203: 32K Point FFT,  
fIN = 30MHz, –10dBFS, PGA = 1  
0
–10  
0
–10  
1±0  
120  
–20  
–20  
–30  
–30  
–±0  
–50  
–±0  
–50  
100  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
80  
60  
±0  
20  
0
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 G20  
22032 G21  
22032 G19  
LTC2203: SFDR vs Input Level,  
fIN = 30.1MHz, PGA = 0,  
Dither “Off”  
LTC2203: SFDR vs Input Level,  
fIN = 30.1MHz, PGA = 0,  
Dither “On”  
LTC2203: 32K Point FFT,  
fIN = 30MHz, –20dBFS, PGA = 1  
0
–10  
–20  
1±0  
120  
1±0  
120  
–30  
–±0  
–50  
100  
100  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
80  
60  
±0  
20  
80  
60  
±0  
20  
0
0
0
2
±
6
8
10  
12  
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
–60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
–80  
–70  
FREQUENCY(MHz)  
22032 G22  
22032 G23  
22032 G2±  
LTC2203: 32K Point FFT,  
LTC2203: 32K Point FFT,  
fIN = 70.1MHz, –10dBFS, PGA = 1  
LTC2203: 32K Point FFT,  
fIN = 70.1MHz, –20dBFS, PGA = 1  
f
IN = 70.1MHz, –1dBFS, PGA = 1  
0
–10  
0
–10  
0
–10  
–20  
–20  
–20  
–30  
–30  
–30  
–±0  
–±0  
–±0  
–50  
–50  
–50  
–60  
–60  
–60  
–70  
–70  
–70  
–80  
–80  
–80  
–90  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 G25  
22032 G26  
22032 G27  
22032fb  
9
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2203: SFDR vs Input Level,  
fIN = 70.1MHz, PGA = 0,  
Dither “Off”  
LTC2203: 32K Point 2-Tone FFT,  
fIN = 44.9MHz and 70.1MHz,  
–7dBFS, PGA = 0  
LTC2203: 32K Point 2-Tone FFT,  
fIN = 44.9MHz and 70.1MHz,  
–15dBFS, PGA = 0  
0
–10  
–20  
0
–10  
–20  
1±0  
120  
–30  
–30  
–±0  
–50  
–±0  
–50  
100  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
–60  
–70  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
80  
60  
±0  
20  
0
0
2
±
6
8
10  
12  
0
2
±
6
8
10  
12  
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
FREQUENCY(MHz)  
FREQUENCY(MHz)  
22032 G28  
22032 G29  
22023 G30  
LTC2203: SFDR vs Input Level,  
fIN = 70.1MHz, PGA = 0,  
Dither “On”  
LTC2203: SFDR (HD2 or HD3) vs  
Input Frequency  
LTC2203: SNR vs Input Frequency  
1±0  
120  
82  
81  
80  
79  
78  
77  
76  
75  
7±  
110  
105  
100  
95  
PGA = 0  
100  
PGA = 1  
80  
60  
±0  
20  
90  
85  
PGA = 1  
PGA = 0  
80  
75  
70  
0
73  
20  
±0  
80  
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
0
100  
60  
0
20  
±0  
60  
1±0  
80 100 120  
ꢀNPUT FREQUENCY (MHz)  
ꢀNPUT FREQUENCY (MHz)  
22032 G31  
22023 G32  
22023 G33  
LTC2203: SNR and SFDR vs  
Sample Rate  
LTC2203: SNR and SFDR vs  
Supply Voltage (VDD), fIN = 5MHz  
LTC2203: IVDD vs Sample Rate,  
5MHz Sine Wave, –1dBFS  
110  
105  
75  
70  
65  
60  
55  
50  
110  
105  
RATED MAX  
SFDR  
UPPER LꢀMꢀT  
LOWER LꢀMꢀT  
SFDR  
100  
100  
95  
90  
85  
80  
95  
90  
85  
80  
SNR  
SNR  
75  
75  
0
15  
25 30 35 ±0 ±5 50  
5
10  
20  
2.8 2.9 3.0 3.1 3.2 3.3 3.± 3.5 3.6  
0
5
15  
SAMPLE RATE (Msps)  
20  
25  
10  
SAMPLE RATE (Msps)  
SUPPLY VOLTAGE (V)  
22023 G36  
22023 G3±  
22023 G35  
22032fb  
10  
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2203: Normalized Full  
LTC2203: SFDR vs Input Common  
Mode Voltage, fIN = 5MHz,  
–1dBFS, PGA = 0  
Scale vs Temperature, Internal  
Reference, 5 Units  
LTC2203: Offset Voltage vs  
Temperature, 5 Units  
6
±
2
0
110  
1.01  
1.005  
1
105  
100  
95  
90  
85  
80  
75  
70  
65  
60  
–2  
–±  
–6  
0.995  
0.99  
±0  
TEMPERATURE (˚C)  
80  
0.5  
0.75  
1.25 1.50 1.75  
2
–±0  
–20  
0
20  
60  
1
–±0  
–20  
0
20  
±0  
60  
80  
TEMPERATURE (°C)  
ꢀNPUT COMMON MODE VOLTAGE (V)  
22023 G38  
22023 G39  
22023 G37  
LTC2202: Integral Nonlinearity  
(INL) vs Output Code  
LTC2202: Differential Nonlinearity  
(DNL) vs Output Code  
LTC2202: AC Grounded Input  
Histogram (256K Samples)  
1.0  
0.8  
0.6  
0.±  
0.2  
0
2.0  
1.5  
50000  
±5000  
±0000  
35000  
30000  
25000  
20000  
15000  
10000  
5000  
1.0  
0.5  
0
0.2  
0.±  
0.6  
0.8  
1.0  
–0.5  
–1.0  
–1.5  
–2.0  
0
32768  
CODE  
0
1638±  
±9152  
65536  
0
1638±  
32768  
CODE  
±9152  
65536  
32793  
32797 32801 32805 32809  
OUTPUT CODE  
22023 G40  
22023 G±1  
22023 G±2  
LTC2202: 128K Point FFT,  
fIN = 5.1MHz, –20dBFS, PGA = 0,  
Internal Dither “Off”  
LTC2202: 128K Point FFT,  
LTC2202: 128K Point FFT,  
fIN = 5.1MHz, –10dBFS, PGA = 0  
f
IN = 5.1MHz, –1dBFS, PGA = 0  
0
–10  
0
–10  
0
–10  
–20  
–20  
–20  
–30  
–30  
–30  
–±0  
–±0  
–±0  
–50  
–50  
–50  
–60  
–60  
–60  
–70  
–70  
–70  
–80  
–80  
–80  
–90  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
1
2
3
±
5
0
1
2
3
±
5
0
1
2
3
±
5
FREQUENCY (MHz)  
FREQUENCY (MHz)  
FREQUENCY (MHz)  
22023 G±5  
22023 G±3  
22023 G±±  
22032fb  
11  
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2203: 128K Point FFT,  
fIN = 5.1MHz, –20dBFS, PGA = 0,  
Internal Dither “On”  
LTC2202: 32K Point 2-Tone FFT,  
fIN = 5.1MHz and 15.2MHz,  
–7dBFS, PGA = 0  
LTC2202: 32K Point 2-Tone FFT,  
fIN = 5.1MHz and 15.2MHz,  
–15dBFS, PGA = 0  
0
–10  
0
–10  
0
–10  
–20  
–30  
–±0  
–50  
–60  
–70  
–20  
–30  
–±0  
–50  
–60  
–70  
–20  
–30  
–±0  
–50  
–60  
–70  
–80  
–90  
–80  
–90  
–80  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
1
2
3
±
5
0
1
2
3
±
5
0
1
2
3
±
5
FREQUENCY (MHz)  
FREQUENCY (MHz)  
FREQUENCY (MHz)  
22023 G±7  
22023 G±8  
22023 G±6  
LTC2202: SFDR vs Input Level,  
fIN = 5MHz, PGA = 0, Dither “Off”  
LTC2202: SFDR vs Input Level,  
fIN = 5MHz, PGA = 0, Dither “On”  
LTC2202: 32K Point FFT,  
fIN = 12.4MHz, –1dBFS, PGA = 0  
0
–10  
–20  
–30  
–±0  
–50  
–60  
–70  
–80  
1±0  
120  
100  
80  
120  
100  
80  
60  
±0  
20  
0
60  
–90  
–100  
–110  
–120  
–130  
–1±0  
±0  
20  
0
5
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
0
1
2
3
±
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
FREQUENCY (MHz)  
22023 G±9  
22023 G51  
22023 G50  
LTC2202: SFDR vs Input Level,  
fIN = 12.4MHz, PGA = 0,  
Dither “Off  
LTC2202: 32K Point FFT,  
LTC2202: 32K Point FFT,  
fIN = 12.4MHz, –10dBFS, PGA = 0  
fIN = 12.4MHz, –20dBFS, PGA = 0  
0
–10  
–20  
–30  
–±0  
–50  
–60  
–70  
–80  
0
–10  
–20  
–30  
–±0  
–50  
–60  
–70  
–80  
120  
100  
80  
60  
±0  
20  
0
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
1
2
3
±
5
0
1
2
3
±
5
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
FREQUENCY (MHz)  
FREQUENCY (MHz)  
22023 G5±  
22023 G52  
22023 G53  
22032fb  
12  
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2202: 32K Point FFT,  
fIN = 30.5MHz, –1dBFS, PGA = 1  
LTC2202: 32K Point FFT,  
fIN = 30.5MHz, –10dBFS, PGA = 1  
LTC2202: 32K Point FFT,  
fIN = 30.5MHz, –20dBFS, PGA = 1  
0
–10  
0
–10  
0
–10  
–20  
–20  
–20  
–30  
–30  
–30  
–±0  
–±0  
–±0  
–50  
–50  
–50  
–60  
–60  
–60  
–70  
–70  
–70  
–80  
–80  
–80  
–90  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
1
2
3
±
5
0
1
2
3
±
5
0
1
2
3
±
5
FREQUENCY (MHz)  
FREQUENCY (MHz)  
FREQUENCY (MHz)  
22023 G55  
22023 G56  
22023 G57  
LTC2202: SFDR vs Input Level,  
IN = 30.1MHz, PGA = 0,  
Dither “Off”  
LTC2202: SFDR vs Input Level,  
fIN = 30.1MHz, PGA = 0,  
Dither “On”  
f
LTC2202: 32K Point FFT,  
fIN = 70.1MHz, –1dBFS, PGA = 1  
0
–10  
–20  
–30  
–±0  
1±0  
120  
100  
80  
1±0  
120  
100  
80  
–50  
–60  
–70  
–80  
60  
60  
–90  
–100  
–110  
–120  
–130  
–1±0  
±0  
±0  
20  
20  
0
0
0
1
2
3
±
5
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
–70 –60 –50 –±0 –30 –20 –10  
ꢀNPUT LEVEL (dBFS)  
0
FREQUENCY (MHz)  
22023 G60  
22023 G58  
22023 G59  
LTC2202: 32K Point FFT,  
fIN = 70.1MHz, –10dBFS, PGA = 1  
LTC2202: 32K Point FFT,  
fIN = 70.1MHz, –20dBFS, PGA = 1  
0
–10  
0
–10  
–20  
–20  
–30  
–30  
–±0  
–±0  
–50  
–50  
–60  
–60  
–70  
–70  
–80  
–80  
–90  
–90  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
0
1
2
3
±
5
0
1
2
3
±
5
FREQUENCY (MHz)  
FREQUENCY (MHz)  
22023 G61  
22023 G62  
22032fb  
13  
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2202: 32K Point 2-Tone FFT,  
fIN = 60.2MHz and 70.1MHz,  
–7dBFS, PGA = 0  
LTC2202: 32K Point 2-Tone FFT,  
fIN = 60.2MHz and 70.1MHz,  
–15dBFS, PGA = 0  
LTC2202: SFDR vs Input Level,  
fIN = 70.1MHz, PGA = 0,  
Dither “Off”  
0
–10  
–20  
–30  
–±0  
–50  
–60  
–70  
0
–10  
–20  
–30  
–±0  
–50  
–60  
–70  
1±0  
120  
100  
80  
–80  
–90  
–80  
–90  
60  
–100  
–110  
–120  
–130  
–1±0  
–100  
–110  
–120  
–130  
–1±0  
±0  
20  
0
0
2
±
0
2
±
–30 –20  
–80 –70 –60 –50 –±0  
–10  
0
FREQUENCY (MHz)  
FREQUENCY (MHz)  
ꢀNPUT LEVEL (dBFS)  
22023 G63  
22023 G6±  
22023 G65  
LTC2202: SFDR vs Input Level,  
IN = 70.1MHz, PGA = 0,  
Dither “On”  
f
LTC2202: SFDR (HD2 or HD3) vs  
Input Frequency  
LTC2202: SNR vs Input Frequency  
1±0  
120  
100  
80  
82  
81  
80  
79  
78  
77  
76  
75  
7±  
110  
105  
100  
95  
PGA = 0  
PGA = 1  
90  
85  
60  
PGA = 1  
PGA = 0  
±0  
80  
75  
70  
20  
0
73  
–30 –20  
–80 –70 –60 –50 –±0  
–10  
0
20  
±0  
80  
0
100  
60  
0
20  
±0  
60  
1±0  
80 100 120  
ꢀNPUT LEVEL (dBFS)  
ꢀNPUT FREQUENCY (MHz)  
ꢀNPUT FREQUENCY (MHz)  
22023 G66  
22023 G67  
22023 G68  
LTC2202: SNR and SFDR vs  
Sample Rate  
LTC2202: SNR and SFDR vs  
Supply Voltage (VDD), fIN = 5MHz  
110  
105  
110  
105  
UPPER LꢀMꢀT  
LOWER LꢀMꢀT  
RATED MAX  
SFDR  
SFDR  
100  
100  
95  
90  
85  
80  
95  
90  
85  
80  
SNR  
SNR  
75  
0
75  
2.8 2.9 3.0 3.1 3.2 3.3 3.± 3.5 3.6  
±
8
12  
20  
16  
SUPPLY VOLTAGE (V)  
SAMPLE RATE (Msps)  
22023 G70  
22023 G69  
22032fb  
14  
LTC2203/LTC2202  
U W  
TYPICAL PERFOR A CE CHARACTERISTICS  
LTC2202: Normalized Full  
Scale vs Temperature, Internal  
Reference, 5 Units  
LTC2202: IVDD vs Sample Rate,  
5MHz Sine Wave, –1dBFS  
50  
±9  
±8  
±7  
±6  
±5  
±±  
±3  
±2  
±1  
±0  
1.01  
1.005  
1
0.995  
0.99  
0
2
±
6
8
10  
–±0  
–20  
0
20  
±0  
60  
80  
TEMPERATURE (°C)  
SAMPLE RATE (Msps)  
22023 G72  
22023 G71  
LTC2202: SFDR vs Input Common  
Mode Voltage, fIN = 5MHz,  
–1dBFS, PGA = 0  
LTC2202: Offset Voltage vs  
Temperature, 5 Units  
110  
105  
100  
95  
6
±
2
0
90  
85  
80  
–2  
–±  
–6  
75  
70  
65  
60  
0.5  
0.75  
1.25 1.50 1.75  
2
1
±0  
TEMPERATURE (˚C)  
80  
–±0  
–20  
0
20  
60  
ꢀNPUT COMMON MODE VOLTAGE (V)  
22023 G7±  
22023 G73  
22032fb  
15  
LTC2203/LTC2202  
U
U
U
PI FU CTIO S  
SENSE(Pin1):ReferenceModeSelectandExternalRefer-  
Drivers. Bypass to ground with 0.1µF capacitor.  
ence ꢀnput. Tie SENSE to V with 1k Ω or less to select  
DD  
CLKOUT (Pin29):DataValidOutput.CLKOUT willtoggle  
theinternal2.5Vbandgapreference.Anexternalreference  
of 2.5V or 1.25V may be used; both reference values will  
set a full scale ADC range of 2.5V (PGA = 0).  
at the sample rate. Latch the data on the falling edge of  
CLKOUT .  
+
+
CLKOUT (Pin 30): ꢀnverted Data Valid Output. CLKOUT  
V
CM  
(Pin2):1.25VOutput.Optimumvoltageforinputcom-  
will toggle at the sample rate. Latch the data on the rising  
mon mode. Must be bypassed to ground with a minimum  
of 2.2µF. Ceramic chip capacitors are recommended.  
+
edge of CLKOUT .  
OF (Pin 43): Over/Under Flow Digital Output. OF is high  
when an over or under flow has occurred.  
V
(Pins 3, 4, 12, 13, 14): 3.3V Analog Supply Pin.  
DD  
Bypass to GND with 0.1µF ceramic chip capacitors.  
OE (Pin 44): Output Enable Pin. Low enables the digital  
output drivers. High puts digital outputs in Hi-Z state.  
GND (Pins 5, 8, 9, 11, 15, 48, 49): ADC Power  
Ground.  
MODE (Pin 45): Output Format and Clock Duty Cycle  
Stabilizer Selection Pin. Connecting MODE to 0V selects  
offset binary output format and disables the clock duty  
+
A
IN  
A
IN  
(Pin 6): Positive Differential Analog ꢀnput.  
(Pin 7): Negative Differential Analog ꢀnput.  
cyclestabilizer.ConnectingMODEto1/3V selectsoffset  
DD  
CLK (Pin 10): Clock ꢀnput. The hold phase of the sample-  
and-hold circuit begins on the falling edge. The output  
data may be latched on the rising edge of CLK.  
binary output format and enables the clock duty cycle sta-  
bilizer.ConnectingMODEto2/3V selects2scomplement  
DD  
output format and enables the clock duty cycle stabilizer.  
SHDN (Pin 16): Power Shutdown Pin. SHDN = low results  
in normal operation. SHDN = high results in powered  
down analog circuitry and the digital outputs are placed  
in a high impedance state.  
Connecting MODE to V selects 2’s complement output  
DD  
format and disables the clock duty cycle stabilizer.  
RAND(Pin46):DigitalOutputRandomizationSelectionPin.  
RAND low results in normal operation. RAND high selects  
D1-D15 to be EXCLUSꢀVE-ORed with D0 (the LSB). The  
outputcanbedecodedbyagainapplyinganXORoperation  
between the LSB and all other bits. The mode of operation  
reduces the effects of digital output interference.  
DITH (Pin 17): ꢀnternal Dither Enable Pin. DꢀTH = low  
disables internal dither. DꢀTH = high enables internal  
dither. Refer to ꢀnternal Dither section of this data sheet  
for details on dither operation.  
D0-D15 (Pins 18-22, 26-28, 32-35 and 39-42): Digital  
PGA(Pin47):ProgrammableGainAmplifierControlPin.Low  
Outputs. D15 is the MSB.  
selects a front-end gain of 1, input range of 2.5V . High  
P-P  
selects a front-end gain of 1.5, input range of 1.667V  
.
OGND (Pins 23, 31 and 38): Output Driver Ground.  
P-P  
GND (Exposed Pad, Pin 49): ADC Power Ground. The ex-  
posed pad on the bottom of the package must be soldered  
to ground.  
OV (Pins24,25,36,37):PositiveSupplyfortheOutput  
DD  
22032fb  
16  
LTC2203/LTC2202  
W
BLOCK DIAGRA  
+
A
A
ꢀN  
ꢀN  
V
DD  
ꢀNPUT  
S/H  
FꢀRST PꢀPELꢀNED  
ADC STAGE  
SECOND PꢀPELꢀNED  
ADC STAGE  
THꢀRD PꢀPELꢀNED  
ADC STAGE  
FOURTH PꢀPELꢀNED  
ADC STAGE  
FꢀFTH PꢀPELꢀNED  
ADC STAGE  
GND  
DꢀTHER  
SꢀGNAL  
GENERATOR  
CORRECTꢀON LOGꢀC  
AND  
SHꢀFT REGꢀSTER  
ADC CLOCKS  
RANGE  
SELECT  
OV  
DD  
CLKOUT+  
CLKOUT–  
OF  
SENSE  
LOW JꢀTTER  
CLOCK  
DRꢀVER  
ADC  
REFERENCE  
PGA  
D15  
D1±  
CONTROL  
LOGꢀC  
OUTPUT  
DRꢀVERS  
V
CM  
BUFFER  
D1  
D0  
VOLTAGE  
REFERENCE  
22032 F01  
OGND  
CLK  
SHDN PGA RAND M0DE DꢀTH  
OE  
Figure 1. Functional Block Diagram  
22032fb  
17  
LTC2203/LTC2202  
U
W U U  
APPLICATIO S I FOR ATIO  
DYNAMIC PERFORMANCE  
ꢀf two pure sine waves of frequencies fa and fb are applied  
totheADCinput,nonlinearitiesintheADCtransferfunction  
can create distortion products at the sum and difference  
frequencies of mfa ± nfb, where m and n = 0, 1, 2, 3, etc.  
For example, the 3rd order ꢀMD terms include (2fa + fb),  
(fa + 2fb), (2fa - fb) and (fa - 2fb). The 3rd order ꢀMD is  
defined as the ratio of the RMS value of either input tone  
to the RMS value of the largest 3rd order ꢀMD product.  
Signal-to-Noise Plus Distortion Ratio  
The signal-to-noise plus distortion ratio [S/(N+D)] is the  
ratiobetweentheRMSamplitudeofthefundamentalinput  
frequency and the RMS amplitude of all other frequency  
components at the ADC output. The output is band lim-  
ited to frequencies above DC to below half the sampling  
frequency.  
Spurious Free Dynamic Range (SFDR)  
Signal-to-Noise Ratio  
The ratio of the RMS input signal amplitude to the RMS  
value of the peak spurious spectral component expressed  
in dBc. SFDR may also be calculated relative to full scale  
and expressed in dBFS.  
The signal-to-noise (SNR) is the ratio between the RMS  
amplitudeofthefundamentalinputfrequencyandtheRMS  
amplitude of all other frequency components, except the  
first five harmonics.  
Full Power Bandwidth  
Total Harmonic Distortion  
The Full Power bandwidth is that input frequency at which  
theamplitudeofthereconstructedfundamentalisreduced  
by 3dB for a full scale input signal.  
Total harmonic distortion is the ratio of the RMS sum  
of all harmonics of the input signal to the fundamental  
itself. The out-of-band harmonics alias into the frequency  
band between DC and half the sampling frequency. THD  
is expressed as:  
Aperture Delay Time  
The time from when CLK reaches 0.±5 of VDD to the  
instant that the input signal is held by the sample-and-  
hold circuit.  
2
2
2
2
THD = 20Log  
(
(V + V + V + ... V )/V  
)
2
3
±
N
1
where V is the RMS amplitude of the fundamental fre-  
1
quencyandV throughV aretheamplitudesofthesecond  
Aperture Delay Jitter  
2
N
through nth harmonics.  
The variation in the aperture delay time from conversion  
to conversion. This random variation will result in noise  
when sampling an AC input. The signal to noise ratio due  
to the jitter alone will be:  
Intermodulation Distortion  
ꢀf the ADC input signal consists of more than one spectral  
component, the ADC transfer function nonlinearity can  
produce intermodulation distortion (ꢀMD) in addition to  
THD. ꢀMD is the change in one sinusoidal input caused  
by the presence of another sinusoidal input at a different  
frequency.  
SNR  
= 20log (2  
π
• f • t  
ꢀN JꢀTTER  
)
JꢀTTER  
22032fb  
18  
LTC2203/LTC2202  
U
W U U  
APPLICATIO S I FOR ATIO  
CONVERTER OPERATION  
SAMPLE/HOLD OPERATION AND INPUT DRIVE  
Sample/Hold Operation  
TheLTC2203/LTC2202areCMOSpipelinedmultistepcon-  
verterswithafront-endPGA.AsshowninFigure1,thecon-  
verterhasvepipelinedADCstages;asampledanaloginput  
will result in a digitized value seven cycles later (see the  
TimingDiagramsection).Theanaloginputisdifferentialfor  
improvedcommonmodenoiseimmunityandtomaximize  
the input range. Additionally, the differential input drive  
will reduce even order harmonics of the sample-and-hold  
circuit.  
Figure 2 shows an equivalent circuit for the LTC2203/  
LTC2202 CMOS differential sample and hold. The differ-  
ential analog inputs are sampled directly onto sampling  
capacitors (C  
) through NMOS transitors. The  
SAMPLE  
capacitors shown attached to each input (C  
) are  
PARASꢀTꢀC  
the summation of all other capacitance associated with  
each input.  
Each pipelined stage shown in Figure 1 contains an ADC,  
a reconstruction DAC and an interstage amplifier. ꢀn  
operation, the ADC quantizes the input to the stage and  
the quantized value is subtracted from the input by the  
DAC to produce a residue. The residue is amplified and  
output by the residue amplifier. Successive stages oper-  
ate out of phase so that when odd stages are outputting  
their residue, the even stages are acquiring that residue  
and vice versa.  
LTC2203/02  
V
DD  
C
C
SAMPLE  
9.1pF  
+
A
ꢀN  
C
PARASꢀTꢀC  
1.±pF  
V
DD  
SAMPLE  
9.1pF  
A
ꢀN  
C
1.±pF  
PARASꢀTꢀC  
The phase of operation is determined by the state of the  
CLK input pin.  
When CLK is high, the analog input is sampled differen-  
tially directly onto the input sample-and-hold capacitors,  
inside the “input S/H” shown in the block diagram. At the  
instant that CLK transitions from high to low, the voltage  
on the sample capacitors is held. While CLK is low, the  
held input voltage is buffered by the S/H amplifier which  
drivestherstpipelinedADCstage.Therststageacquires  
the output of the S/H amplifier during the low phase of  
CLK. When CLK goes back high, the first stage produces  
its residue which is acquired by the second stage. At the  
sametime,theinputS/Hgoesbacktoacquiringtheanalog  
input. When CLK goes low, the second stage produces its  
residue which is acquired by the third stage. An identi-  
cal process is repeated for the third and fourth stages,  
resulting in a fourth stage residue that is sent to the fifth  
stage for final evaluation.  
CLK  
22032 F02  
Figure 2. Equivalent Input Circuit  
During the sample phase when CLK is high, the NMOS  
transistors connect the analog inputs to the sampling  
capacitors and they charge to, and track the differential  
input voltage. When CLK transitions from high to low, the  
sampled input voltage is held on the sampling capacitors.  
During the hold phase when CLK is high, the sampling  
capacitors are disconnected from the input and the held  
voltage is passed to the ADC core for processing. As CLK  
transitions from low to high, the inputs are reconnected to  
the sampling capacitors to acquire a new sample. Since  
the sampling capacitors still hold the previous sample,  
a charging glitch proportional to the change in voltage  
between samples will be seen at this time at the input of  
the converter. ꢀf the change between the last sample and  
Each ADC stage following the first has additional range to  
accommodate flash and amplifier offset errors. Results  
from all of the ADC stages are digitally delayed such that  
the results can be properly combined in the correction  
logic before being sent to the output buffer.  
22032fb  
19  
LTC2203/LTC2202  
U
W U U  
APPLICATIO S I FOR ATIO  
the new sample is small, the charging glitch seen at the  
input will be small. ꢀf the input change is large, such as  
the change seen with input frequencies near Nyquist, then  
a larger charging glitch will be seen.  
a 1:1 turns ratio transformer. Other turns ratios can be  
used; however, as the turns ratio increases so does the  
impedance seen by the ADC. Source impedance greater  
than 50Ω can reduce the input bandwidth and increase  
high frequency distortion. A disadvantage of using a  
transformer is the loss of low frequency response. Most  
small RF transformers have poor performance at frequen-  
cies below 1MHz.  
Common Mode Bias  
The ADC sample-and-hold circuit requires differential  
drive to achieve specified performance. Each input may  
swing ±0.625V for the 2.5V range (PGA = 0) or ±0.±17V  
for the 1.667V range (PGA = 1), around a common mode  
V
CM  
voltage of 1.25V. The V output pin (Pin 3) is designed  
CM  
T1  
1:1  
+
A
to provide the common mode bias level. V can be tied  
ꢀN  
ANALOG  
ꢀNPUT  
CM  
LTC2203/02  
directly to the center tap of a transformer to set the DC  
input level or as a reference level to an op amp differential  
12pF  
12pF  
driver circuit. The V pin must be bypassed to ground  
CM  
A
ꢀN  
close to the ADC with 2.2µF or greater.  
T1 = COꢀLCRAFT WBCꢀ-ꢀT OR  
MA/COM ETC1-1T.  
12pF  
22032 F03  
Input Drive Impedence  
RESꢀSTORS, CAPACꢀTORS ARE  
0±02 PACKAGE SꢀZE, EXCEPT 2.2μF.  
As with all high performance, high speed ADCs the  
dynamic performance of the LTC2203/LTC2202 can be  
influenced by the input drive circuitry, particularly the  
second and third harmonics. Source impedance and  
input reactance can influence SFDR. At the rising edge of  
CLK the sample and hold circuit will connect the 9.1pF  
sampling capacitor to the input pin and start the sampling  
period. The sampling period ends when CLK falls, hold-  
ing the sampled input on the sampling capacitor. ꢀdeally,  
the input circuitry should be fast enough to fully charge  
the sampling capacitor during the sampling period  
Figure 3. Single-Ended to Differential Conversion  
Using a Transformer. Recommended for Input  
Frequencies from 1MHz to 100MHz  
Center-tapped transformers provide a convenient means  
of DC biasing the secondary; however, they often show  
poor balance at high input frequencies, resulting in large  
2nd order harmonics.  
Figure ± shows transformer coupling using a transmis-  
sion line balun transformer. This type of transformer has  
muchbetterhighfrequencyresponseandbalancethanux  
coupled center tap transformers. Coupling capacitors are  
added at the ground and input primary terminals to allow  
the secondary terminals to be biased at 1.25V.  
1/(2F ); however, this is not always possible and the  
CLK  
incomplete settling may degrade the SFDR. The sampling  
glitch has been designed to be as linear as possible to  
minimize the effects of incomplete settling.  
V
CM  
Forthebestperformanceitisrecomendedtohaveasource  
impedence of 100Ω or less for each input. The source  
impedence should be matched for the differential inputs.  
Poor matching will result in higher even order harmonics,  
especially the second.  
2.2μF  
0.1μF  
+
A
A
ꢀN  
ꢀN  
ANALOG  
ꢀNPUT  
LTC2203/02  
0.1μF  
±.7pF  
T1  
1:1  
±.7pF  
0.1μF  
INPUT DRIVE CIRCUITS  
±.7pF  
T1 = MA/COM ETC1-1-13.  
RESꢀSTORS, CAPACꢀTORS  
ARE 0±02 PACKAGE SꢀZE,  
EXCEPT 2.2F.  
22032 F0±  
Figure 3 shows the LTC2203/LTC2202 being driven by  
an RF transformer with a center-tapped secondary. The  
secondary center tap is DC biased with V , setting the  
ADC input signal at its optimum DC level. Figure 3 shows  
Figure 4. Using a Transmission Line Balun Transformer.  
Recommended for Input Frequencies from 50MHz to 250MHz  
CM  
22032fb  
20  
LTC2203/LTC2202  
U
W U U  
APPLICATIO S I FOR ATIO  
Figure 5 demonstrates the use of an LTC199± differential  
amplifier to convert a single ended input signal into a  
differential input signal. The advantage of this method is  
that it provides low frequency input response; however,  
the limited gain bandwidth of any op amp will limit the  
SFDR at high input frequencies.  
The internal programmable gain amplifier provides the  
internal reference voltage for the ADC. This amplifier has  
very stringent settling requirements and is not accessible  
for external use.  
LTC2203/02  
RANGE  
SELECT  
V
CM  
AND GAꢀN  
CONTROL  
TꢀE TO V TO USE  
DD  
2.2 μF  
ꢀNTERNAL  
ADC  
REFERENCE  
ꢀNTERNAL 2.5V  
REFERENCE  
±99Ω  
S
100pF  
OR ꢀNPUT FOR  
EXTERNAL 2.5V  
REFERENCE  
LTC2203/02  
SENSE  
+
523Ω  
A
A
ꢀN  
PGA  
+
OR ꢀNPUT FOR  
EXTERNAL 1.25V  
REFERENCE  
100pF  
CM LT199±  
±99Ω  
+
ꢀN  
2.5V  
BANDGAP  
REFERENCE  
53.6Ω  
100pF  
22032 F05  
±99Ω  
V
CM  
1.25V  
BUFFER  
2.2μF  
Figure 5. DC Coupled Input with Differential Amplifier  
22032 F07  
The 25Ω resistors and 12pF capacitor on the analog  
inputs serve two purposes: isolating the drive circuitry  
from the sample-and-hold charging glitches and limiting  
the wideband noise at the converter input.  
Figure 6. Reference Circuit  
TheSENSEpincanbedriven±5aroundthenominal2.5V  
or 1.25V external reference input. This adjustment range  
can be used to trim the ADC gain error or other system  
gain errors. When selecting the internal reference, the  
Reference Operation  
Figure 6 shows the LTC2203/LTC2202 reference circuitry  
consisting of a 2.5V bandgap reference, a programmable  
gain amplifier and control circuit. The LTC2203/LTC2202  
has three modes of reference operation: ꢀnternal Refer-  
ence, 1.25V external reference or 2.5V external reference.  
SENSE pin should be tied to V as close to the converter  
DD  
as possible. ꢀf the sense pin is driven externally it should  
be bypassed to ground as close to the device as possible  
with at least a 1µF ceramic capacitor.  
To use the internal reference, tie the SENSE pin to V . To  
DD  
use the external reference, simply apply either a 1.25V or  
2.5V referencevoltagetotheSENSEinputpin. Both1.25V  
and 2.5V applied to SENSE will result in a full scale range  
V
CM  
1.25V  
2.2μF  
of 2.5V (PGA = 0). A 1.25V output, V , is provided  
P-P  
CM  
LTC2203/02  
for a common mode bias for input drive circuitry. An  
SENSE  
6
2
3.3V  
1μF  
LT1±61-2.5  
±
external bypass capacitor is required for the V output.  
CM  
2.2μF  
This provides a high frequency low impedance path to  
ground for internal and external circuitry. This is also the  
compensation capacitor for the reference; it will not be  
stablewithoutthiscapacitor. Theminimumvaluerequired  
for stability is 2.2µF.  
22032 F08  
Figure 7. A 2.25V Range ADC with  
an External 2.5V Reference  
22032fb  
21  
LTC2203/LTC2202  
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APPLICATIO S I FOR ATIO  
PGA Pin  
ꢀn applications where jitter is critical, such as when digi-  
tizing high input frequencies, use as large an amplitude  
as possible. ꢀt is also helpful to drive the CLK pin with a  
low-jitter high frequency source which has been divided  
down to the appropriate sample rate. ꢀf the ADC is clocked  
with a sinusoidal signal, filter the CLK signal to reduce  
wideband noise and distortion products generated by  
the source.  
ThePGApinselectsbetweentwogainsettingsfortheADC  
front-end.PGA=0selectsaninputrangeof2.5V ;PGA=  
P-P  
1selectsaninputrangeof1.667V . The2.5Vinputrange  
P-P  
hasthebestSNR;however, thedistortionwillbehigherfor  
inputfrequenciesabove100MHz.Forapplicationswithhigh  
input frequencies, the low input range will have improved  
distortion; however, the SNR will be 2.±dB worse. See the  
Typical Performance Characteristics section.  
Maximum and Minimum Conversion Rates  
Driving the Clock Input  
ThemaximumconversionratefortheLTC2203is25Msps.  
ThemaximumconversionratefortheLTC2202is10Msps.  
FortheADCtooperateproperlytheCLKsignalshouldhave  
a50(±5ꢁ)dutycycle. Eachhalfcyclemusthaveatleast  
18.9ns for the LTC2203 internal circuitry to have enough  
settling time for proper operation. For the LTC2202, each  
half cycle must be at least ±0ns.  
The CLK input can be driven directly with a CMOS or TTL  
levelsignal.Asinusoidalclockcanalsobeusedalongwitha  
low-jitter squaring circuit before the CLK pin (Figure 8).  
CLEAN 3.3V  
SUPPLY  
±.7μF  
An on-chip clock duty cycle stabilizer may be activated if  
theinputclockdoesnothavea50dutycycle.Thiscircuit  
usesthefallingedgeofCLKpintosampletheanaloginput.  
The rising edge of CLK is ignored and an internal rising  
edge is generated by a phase-locked loop. The input clock  
duty cycle can vary from 30ꢁ to 70ꢁ and the clock duty  
cycle stabilizer will maintain a constant 50ꢁ internal duty  
cycle. ꢀf the clock is turned off for a long period of time,  
the duty cycle stabilizer circuit will require one hundred  
clock cycles for the PLL to lock onto the input clock. To  
use the clock duty cycle stabilizer, the MODE pin must be  
FERRꢀTE  
BEAD  
0.1μF  
1k  
0.1μF  
SꢀNUSOꢀDAL  
CLOCK  
CLK  
LTC2203/02  
ꢀNPUT  
56Ω  
NC7SVU0±  
1k  
22032 F09  
Figure 8. Sinusoidal Single-Ended CLK Drive  
connected to 1/3V or 2/3V using external resistors.  
DD  
DD  
The noise performance of the LTC2203/2202 can depend  
on the clock signal quality as much as on the analog  
input. Any noise present on the clock signal will result in  
additional aperture jitter that will be RMS summed with  
the inherent ADC aperture jitter.  
The lower limit of the LTC2203/LTC2202 sample rate is  
determined by droop of the sample and hold circuits. The  
pipelined architecture of this ADC relies on storing analog  
signals on small valued capacitors. Junction leakage will  
dischargethecapacitors.Thespecifiedminimumoperating  
frequency for the LTC2203/LTC2202 is 1Msps.  
22032fb  
22  
LTC2203/LTC2202  
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DIGITAL OUTPUTS  
Data Format  
Digital Output Buffers  
The LTC2203/LTC2202 parallel digital output can be  
selected for offset binary or 2’s complement format. The  
format is selected with the MODE pin. This pin has a four  
Figure 9 shows an equivalent circuit for a single output  
buffer in CMOS Mode. Each buffer is powered by OVDD  
and OGND, isolated from the ADC power and ground. The  
additional N-channel transistor in the output driver allows  
operation down to low voltages. The internal resistor in  
series with the output makes the output appear as 50Ω  
to external circuitry and eliminates the need for external  
damping resistors.  
level logic input, centered at 0, 1/3V , 2/3V and V .  
DD  
DD  
DD  
An external resistor divider can be user to set the 1/3V  
DD  
and 2/3V logic levels. Table 1 shows the logic states  
DD  
for the MODE pin.  
Table 1. MODE Pin Function  
Clock Duty  
As with all high speed/high resolution converters, the  
digital output loading can affect the performance. The  
digital outputs of the LTC2203/LTC2202 should drive a  
minimum capacitive load to avoid possible interaction  
between the digital outputs and sensitive input circuitry.  
The output should be buffered with a device such as a  
ALVCH16373 CMOS latch. For full speed operation the  
capacitive load should be kept under 10pF. A resistor in  
series with the output may be used but is not required  
since the ADC has a series resistor of ±3Ω on chip.  
MODE  
Output Format  
Offset Binary  
Cycle Stabilizer  
0(GND)  
Off  
On  
On  
Off  
1/3V  
Offset Binary  
DD  
2/3V  
2’s Complement  
2’s Complement  
DD  
V
DD  
Overflow Bit  
An overflow output bit (OF) indicates when the converter  
is over-ranged or under-ranged. A logic high on the OF  
pin indicates an overflow or underflow.  
Lower OV voltages will also help reduce interference  
DD  
Output Clock  
from the digital outputs.  
The ADC has a delayed version of the CLK input available  
+
as a digital output. Both a noninverted version, CLKOUT  
LTC2203/02  
OV  
DD  
and an inverted version CLKOUT are provided. The  
0.5V  
+
TO 3.6V  
V
V
CLKOUT /CLKOUT can be used to synchronize the con-  
verter data to the digital system. This is necesary when  
using a sinusoidal clock. Data can be latched on the ris-  
ing edge of CLKOUT+ or the falling edge of CLKOUT–.  
CLKOUT+ falls and CLKOUT– rises as the data outputs  
are updated.  
DD  
DD  
0.1μF  
OV  
DD  
DATA  
FROM  
LATCH  
PREDRꢀVER  
LOGꢀC  
±3Ω  
TYPꢀCAL  
DATA  
OUTPUT  
OGND  
22032 F10  
Figure 9. Equivalent Circuit for a Digital Output Buffer  
22032fb  
23  
LTC2203/LTC2202  
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APPLICATIO S I FOR ATIO  
Digital Output Randomizer  
The digital output is “Randomized” by applying an exclu-  
sive-ORlogicoperationbetweentheLSBandallotherdata  
output bits. To decode, the reverse operation is applied;  
that is, an exclusive-OR operation is applied between the  
LSB and all other bits. The LSB, OF and CLKOUT output  
are not affected. The output Randomizer function is active  
when the RAND pin is high.  
ꢀnterference from the ADC digital outputs is sometimes  
unavoidable. ꢀnterference from the digital outputs may be  
from capacitive or inductive coupling or coupling through  
the ground plane. Even a tiny coupling factor can result in  
discernible unwanted tones in the ADC output spectrum.  
By randomizing the digital output before it is transmitted  
offchip,theseunwantedtonescanberandomized,trading  
a slight increase in the noise floor for a large reduction in  
unwanted tone amplitude.  
LTC2203/02  
CLKOUT  
CLKOUT  
OF  
OF  
D15  
D15/D0  
D1±/D0  
D1±  
D2  
D1  
D2/D0  
D1/D0  
RAND = HꢀGH,  
RAND  
SCRAMBLE  
ENABLED  
D0  
D0  
22032 F11  
Figure 10. Functional Equivalent of Digital Output Randomizer  
22032fb  
24  
LTC2203/LTC2202  
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APPLICATIO S I FOR ATIO  
Output Driver Power  
Separate output power and ground pins allow the output  
drivers to be isolated from the analog circuitry. The power  
a 1.8V supply, then OV should be tied to that same 1.8V  
DD  
supply.nCMOSmodeOV canbepoweredwithanylogic  
DD  
supply for the digital output buffers, OV , should be tied  
voltage up to 3.6V. OGND can be powered with any voltage  
DD  
to the same power supply as for the logic being driven.  
For example, if the converter is driving a DSP powered by  
from ground up to 1V and must be less than OV . The  
DD  
logic outputs will swing between OGND and OV .  
DD  
PC BOARD  
FPGA  
CLKOUT  
OF  
D15/D0  
D15  
D1±  
LTC2203/02  
D1±/D0  
D2/D0  
D1/D0  
D2  
D1  
D0  
D0  
22032 F12  
Figure 11. Descrambling a Scrambled Digital Output  
22032fb  
25  
LTC2203/LTC2202  
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APPLICATIO S I FOR ATIO  
Grounding and Bypassing  
Internal Dither  
TheLTC2203/LTC2202requireaprintedcircuitboardwitha  
clean unbroken ground plane; a multilayer board with an  
internal ground plane is recommended. The pinout of the  
LTC2203/LTC2202 has been optimized for a flowthrough  
layout so that the interaction between inputs and digital  
outputs is minimized. Layout for the printed circuit board  
should ensure that digital and analog signal lines are  
separated as much as possible. ꢀn particular, care should  
be taken not to run any digital track alongside an analog  
signal track or underneath the ADC.  
The LTC2203/LTC2202 are 16-bit ADCs with very linear  
transfer functions; however, at low input levels even  
slight imperfections in the transfer function will result in  
unwanted tones. Small errors in the transfer function are  
usually a result of ADC element mismatches. An optional  
internal dither mode can be enabled to randomize the  
input’s location on the ADC transfer curve, resulting in  
improved SFDR for low signal levels.  
As shown in Figure 12, the output of the sample-and-hold  
amplifier is summed with the output of a dither DAC. The  
dither DAC is driven by a long sequence pseudo-random  
number generator; the random number fed to the dither  
DAC is also subtracted from the ADC result. ꢀf the dither  
DAC is precisely calibrated to the ADC, very little of the  
dither signal will be seen at the output. The dither signal  
thatdoesleakthroughwillappearaswhitenoise.Thedither  
DAC is calibrated to result in less than 0.5dB elevation in  
the noise floor of the ADC, as compared to the noise floor  
with dither off.  
High quality ceramic bypass capacitors should be used  
at the V  
V
, and OV pins. Bypass capacitors must  
DD, CM DD  
be located as close to the pins as possible. The traces  
connecting the pins and bypass capacitors must be kept  
short and should be made as wide as possible.  
The LTC2203/LTC2202 differential inputs should run  
parallel and close to each other. The input traces should  
be as short as possible to minimize capacitance and to  
minimize noise pickup.  
LTC2203/02  
CLKOUT+  
CLKOUT–  
Heat Transfer  
+
OF  
D15  
A
ꢀN  
16-BꢀT  
PꢀPELꢀNED  
ADC CORE  
DꢀGꢀTAL  
SUMMATꢀON  
Most of the heat generated by the LTC2203/LTC2202 is  
transferred from the die through the bottom-side exposed  
pad. For good electrical and thermal performance, the  
exposed pad must be soldered to a large grounded pad  
on the PC board. ꢀt is critical that the exposed pad and all  
ground pins are connected to a ground plane of sufficient  
area with as many vias as possible.  
ANALOG  
ꢀNPUT  
OUTPUT  
DRꢀVERS  
S/H  
AMP  
D0  
A
ꢀN  
CLOCK/DUTY  
CYCLE  
CONTROL  
MULTꢀBꢀT DEEP  
PSEUDO-RANDOM  
NUMBER  
PRECꢀSꢀON  
DAC  
GENERATOR  
22032 F13  
CLK  
DꢀTH  
DꢀTHER ENABLE  
HꢀGH = DꢀTHER ON  
LOW = DꢀTHER OFF  
Figure 12. Functional Equivalent Block Diagram of  
Internal Dither Circuit  
22032fb  
26  
LTC2203/LTC2202  
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APPLICATIO S I FOR ATIO  
G N D  
± 9  
2 ±  
D D  
D D  
O V  
O V  
3 7  
O G N D  
O G N D  
2 3  
2 2  
2 1  
2 0  
3 8  
3 9  
± 0  
± 1  
D 1 2  
D ±  
D 3  
D 2  
D 1  
D 1 3  
D 1 ±  
D 1 5  
1 9  
± 2  
O F  
D 0  
1 8  
1 7  
± 3  
± ±  
O E  
D ꢀ T H  
S H D N  
G N D  
M O D E  
R A N D  
1 6  
1 5  
± 5  
± 6  
D D  
V
P G A  
G N D  
1 ±  
1 3  
± 7  
± 8  
D D  
V
22032fb  
27  
LTC2203/LTC2202  
U
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APPLICATIO S I FOR ATIO  
Silkscreen Top  
Silkscreen Topside  
22032fb  
28  
LTC2203/LTC2202  
U
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APPLICATIO S I FOR ATIO  
Inner Layer 2  
Inner Layer 3  
22032fb  
29  
LTC2203/LTC2202  
U
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APPLICATIO S I FOR ATIO  
Silkscreen Bottom Side  
Silkscreen Bottom  
22032fb  
30  
LTC2203/LTC2202  
U
PACKAGE DESCRIPTIO  
UK Package  
48-Lead Plastic QFN (7mm × 7mm)  
(Reference LTC DWG # 05-08-170±)  
0.70 0.05  
5.15 0.05  
5.50 REF  
6.10 0.05 7.50 0.05  
(± SꢀDES)  
5.15 0.05  
PACKAGE OUTLꢀNE  
0.25 0.05  
0.50 BSC  
RECOMMENDED SOLDER PAD PꢀTCH AND DꢀMENSꢀONS  
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED  
0.75 0.05  
R = 0.115  
TYP  
7.00 0.10  
(± SꢀDES)  
R = 0.10  
TYP  
±7 ±8  
0.±0 0.10  
PꢀN 1 TOP MARK  
(SEE NOTE 6)  
1
2
PꢀN 1  
CHAMFER  
C = 0.35  
5.15 0.10  
5.50 REF  
(±-SꢀDES)  
5.15 0.10  
(UK±8) QFN 0±06 REV C  
0.200 REF  
0.25 0.05  
0.00 – 0.05  
0.50 BSC  
NOTE:  
1. DRAWꢀNG CONFORMS TO JEDEC PACKAGE OUTLꢀNE MO-220 VARꢀATꢀON (WKKD-2)  
2. DRAWꢀNG NOT TO SCALE  
BOTTOM VꢀEW—EXPOSED PAD  
3. ALL DꢀMENSꢀONS ARE ꢀN MꢀLLꢀMETERS  
±. DꢀMENSꢀONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT ꢀNCLUDE  
MOLD FLASH. MOLD FLASH, ꢀF PRESENT, SHALL NOT EXCEED 0.20mm ON ANY SꢀDE, ꢀF PRESENT  
5. EXPOSED PAD SHALL BE SOLDER PLATED  
6. SHADED AREA ꢀS ONLY A REFERENCE FOR PꢀN 1 LOCATꢀON ON THE TOP AND BOTTOM OF PACKAGE  
22032fb  
ꢀnformationfurnishedbyLinearTechnologyCorporationisbelievedtobeaccurateandreliable.However,  
no responsibility is assumed for its use. Linear Technology Corporation makes no representation that  
the interconnection of its circuits as described herein will not infringe on existing patent rights.  
31  
LTC2203/LTC2202  
RELATED PARTS  
PART NUMBER DESCRIPTION  
COMMENTS  
LTC17±8  
LTC1750  
LT1993-2  
LT199±  
1±-Bit, 80Msps ADC  
1±-Bit, 80Msps Wideband ADC  
High Speed Differential Op Amp  
Low Noise, Low Distortion Fully  
Differential ꢀnput/Output Amplifier/Driver  
76.3dB SNR, 90dB SFDR, ±8-Pin TSSOP Package  
Up to 500MHz ꢀF Undersampling, 90dB SFDR  
800MHz BW, 70dBc Distortion at 70MHz, 6dB Gain  
Low Distortion: –9±dBc at 1MHz  
LTC220±  
LTC2205  
LTC2206  
LTC2207  
LTC2208  
LTC2220-1  
LTC222±  
LTC22±2-12  
LTC2255  
LTC228±  
LT5512  
16-Bit, ±0Msps, 3.3V ADC  
16-Bit, 65Msps, 3.3V ADC  
16-Bit, 80Msps, 3.3V ADC  
16-Bit, 105Msps, 3.3V ADC  
16-Bit, 130Msps, 3,3V ADC, LVDS Outputs  
12-Bit, 185Msps, 3.3V ADC, LVDS Outputs  
12-Bit, 135Msps, 3.3V ADC, High ꢀF Sampling  
12-Bit, 250Msps, 2.5V ADC, LVDS Outputs  
1±-Bit, 125Msps, 3V ADC, Lowest Power  
1±-Bit, Dual, 105Msps, 3V ADC, Low Crosstalk  
±80mW, 79.1dB SNR, 100dB SFDR, ±8-Pin QFN  
610mW, 79dB SNR, 100dB SFDR, ±8-Pin QFN  
725mW, 77.9dB SNR, 100dB SFDR, ±8-Pin QFN  
900mW, 77.9dB SNR, 100dB SFDR, ±8-Pin QFN  
1250mW, 77.1dB SNR, 100dB SFDR, 6±-Pin QFN  
910mW, 67.7dB SNR, 80dB SFDR, 6±-Pin QFN  
630mW, 67.6dB SNR, 8±dB SFDR, ±8-Pin QFN  
7±0mW, 65.±dB SNR, 8±dB SFDR, 6±-Pin QFN  
395mW, 72.5dB SNR, 88dB SFDR, 32-Pin QFN  
5±0mW, 72.±dB SNR, 88dB SFDR, 6±-pin QFN  
DC to 3GHz, 21dBm ꢀꢀP3, ꢀntegrated LO Buffer  
DC-3GHz High Signal Level  
Downconverting Mixer  
LT551±  
LT5515  
LT5516  
LT5517  
LT5522  
Ultralow Distortion ꢀF Amplifier/ADC Driver  
with Digitally Controlled Gain  
1.5GHz to 2.5GHz Direct Conversion  
Quadrature Demodulator  
800MHz to 1.5GHz Direct Conversion  
Quadrature Demodulator  
±0MHz to 900MHz Direct Conversion  
Quadrature Demodulator  
±50MHz to 1dB BW, ±7dB OꢀP3, Digital Gain Control 10.5dB to 33dB in 1.5dB/Step  
High ꢀꢀP3: 20dBm at 1.9GHz, ꢀntegrated LO Quadrature Generator  
High ꢀꢀP3: 21.5dBm at 900MHz, ꢀntegrated LO Quadrature Generator  
High ꢀꢀP3: 21dBm at 800MHz, ꢀntegrated LO Quadrature Generator  
600MHz to 2.7GHz High Linearity  
Downconverting Mixer  
±.5V to 5.25V Supply, 25dBm ꢀꢀP3 at 900MHz. NF = 12.5dB, 50Ω Single Ended  
RF and LO Ports  
22032fb  
LT 0507 REV B • PRINTED IN USA  
LinearTechnology Corporation  
1630 McCarthy Blvd., Milpitas, CA 95035-7±17  
32  
© LINEAR TECHNOLOGY CORPORATION 2006  
(±08) ±32-1900 FAX: (±08) ±3±-0507 www.linear.com  

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