SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
A single reference voltage generation source must be shared by all ADC modules. This minimizes reference voltage mismatch between ADC modules. The reference voltage must then be buffered by a precision op-amp with good bandwidth and low output impedance before being driven into the reference pin. A capacitor between the high and low reference pins must be placed on the PCB as close to the pins as practical to help absorb high-frequency currents. A series resistor (typically <1Ω) in series with this capacitor can be necessary to make sure op-amp stability. The example shown can be repeated for each instance of ADC reference voltage inputs.