Input Amplifier Configurations; Figure 6-9. Input Amplifier Configuration Examples - Texas Instruments ADS8332EVMV2-PDK User Manual

ADS8332EVMV2-PDK Operation

6.6 Input Amplifier Configurations

The ADS8332EVMV2 is designed so the user can configure the input amplifier in many different topologies. The
EVM comes with the input as a unity gain buffer because this is applicable to the majority of SAR ADC designs.
All eight of the input amplifiers have unpopulated components that allow for configurability.
Figure 6-9 shows three different input amplifier options for the ADS8332EVMV2. First, is the buffer configuration
and this is how the EVM will initially be populated. Next, is an inverting configuration for when the dc offset
of the input signal is zero. This topology will superimpose the input signal onto the voltage REF/2. Lastly, the
bottom inverting configuration should be used for an input signal with the dc offset of VREF/2. This amplifier will
maintain the dc offset of VREF/2.
The input amplifiers can be adjusted in many different ways to produce gains, filters, and a number of other
functions. These input configurations are not tested and may require a higher bandwidth amplifier than what is
populated on the ADS8332EVMV2.
4.096 V
2.048 V
0 V
+2.048 V
0
–2.048 V
DC Offset = REF/2
4.096 V
2.048 V
0
20 ADS8332EVMV2-PDK Evaluation Module
Input
1 k
¡
Input With
DC Offset = 0 V
1 k
¢
1 k
§
+
REF/4
–
Input With
1 k
¤
1 k
¦
+
REF/2
–

Figure 6-9. Input Amplifier Configuration Examples

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– 40.2 k
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SBAU251B – JULY 2017 – REVISED FEBRUARY 2023
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4.096 V
To ADC
2.048 V
0 V
4.096 V
2.048 V
To ADC
0
4.096 V
2.048 V
To ADC
0
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