THS1031 Datasheet, PDF (17/26 Pages) Texas Instruments – 2.7 V . 5.5 V, 10-BIT, 30 MSPS CMOS ANALOG-TO-DIGITAL CONVERTER

THS1031
2.7 V – 5.5 V, 10-BIT, 30 MSPS
CMOS ANALOG-TO-DIGITAL CONVERTER
SLAS242A – NOVEMBER 1999 – REVISED JANUARY 2000
PRINCIPLES OF OPERATION
analog input mode(continued)
REFTF
REFBF
AIN
REFTS
THS1031
SHA
PGA
A/D
REFBS
MODE
0.1
µF
REFT
0.1 µF
REFB
0.1 µF
0.1 µF
0.1 µF
REFTF
10 µF
REFBF
SW3
Figure 16. Kelvin Connection With External ADC Reference Mode
D Internal ADC Reference Mode With External Input Common Mode: The input common mode is supplied
to pins REFTS and REFBS while connected together. The input signal should be centered around this
common mode with peak-to-peak input equal to the voltage on the V_REF pin. Input can be either dc-coupled
or ac-coupled to the same common mode voltage (Figure 17) or any other voltage within the input voltage
range.
2V
1V
1.5 V
AVDD
AIN
REFTS
REFBS
MODE
VREF
REFSENSE
THS1031
SHA
PGA
A/D
+
–+
_
1V
ADC
REF
REFTF
0.1 µF
REFBF
0.1 µF
10 µF
0.1 µF
Figure 17. External Input Common Mode
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