PIC24FV32KAxxx ADC Nonlinearity.
Doing some testing of an ADC on a PIC24FV32KA304. ADC is set for 12Bit.
Slowly sweeping the input voltage, there appears to be a rather large nonlinearity at 2048 of about 30 counts. A second one at 3072 of about 25 counts and another one around 1536. Not surprisingly these are on a power of two boundry. I was surprised how large they are. Anyone else run into issues with the ADC and nonlinearities?
Otherwise, they ADC appears relativley linear. Full scale average linearity looks good. (If you ignore the noise of between +/- 5 to +/- 10 counts, but that could be my source, or power supply rail).
FYI, source is slow sweep triangle wave (2.5mHz) and through 10Khz LPF opamp driven source.