18F8723 - 12 bit A/D

[Steve_88]

Hi Charles,

Are you using an opamp to buffer and filter the input to the AtoD channels?
Thanks,
-Steve

[Charles Linquis]

No, I'm measuring power supply voltages, so my source impedance is low. I generally use a voltage divider with about a 2K source Z and a .1uF cap to the analog GND plane right at the PIC's analog input. I get good results. It also helps that I use a 0.1% low-noise Vref and average at least 6 samples.