SBAU408 august 2023 ADS7953
The ADS7953 operates off of an external 2.5-V voltage reference. By default, the ADS7953 EVM is configured to work with an onboard 2.5-V reference voltage supplied by the REF5025. By default, a shunt is applied on positions 1-2 on JP4.
There is also a provision to bypass the onboard voltage reference and supply an external voltage reference to the ADS7953 REFP pin. When supplying the board with an external reference, the onboard voltage reference must be disabled by adding a shunt across position 2-3 on JP4 and the external reference can be applied on TP5. Supplying an external voltage reference to the EVM allows for the 2 × VREF mode of the ADS7953.
The ADS7953 REFM pin is set to ground by default. However, a different voltage can be used by removing R21 and applying the desired REF_M voltage to TP4.