Wish to measure three small voltages (<1V) on a 16f676. Set Vref to 1.023V, but found the reading fluctutes with an injected voltage of 100mV on AN1. Checked AN1 ok with internal vref. This raises two questions:
1. What is the lowest practical value of Vref for the ADC to work correctly?
2. Does Vref require a buffer or filter capacitor - Checked with scope and Vref looked smooth?
Thanks
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