Texas Instruments ADS794xEVM, User Manual, Page: 6 / 31

4
10
12
No SMA
J10
SMA
J11
No SMA
J4
SMA
J5
A0(+)
A1(+)
A0( )
-
A1( )
-
OPA836 in Inverting
Configuration
OPA836 in Inverting
Configuration
P2
AIN1P (pin 8)
AIN1N (pin 7)
AIN0P (pin 5)
AIN0N (pin 6)
ADS7946
Open
Open
Analog Interface
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6 SBAU194B – August 2011 – Revised September 2017
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ADS794xEVM and ADS794xEVM-PDK
2.2 ADS794xEVM Analog Inputs with ADS7946 Installed
Each channel of the ADS7946 uses one OPA836 to drive a single-ended input voltage. The input signals
can be applied to either the SMA or P2 header connectors. These operational amplifiers offset the input
signal to use an inverting configuration with a single supply. The
EVM Operation section explains in detail
how this offset is used to allow bipolar signals for the ADS7946 with jumper J6.
Figure 2 shows the ADS794xEVM analog inputs with the ADS7946 installed.
Figure 2. ADS794xEVM and ADS7946 Analog Inputs
2.3 External Reference Input
Pin P2.20 is an analog input for an external reference voltage when J2 is in position 2-3. The source that
provides this external reference should have a voltage between 2.5 V and the analog power-supply
voltage.