Hi David, It's not just a measuring problem, like your scope ground lead picking up s= omething extraneous? Do you have another ADC input you can enable to verify that it's definitely= only that pin glitching when you sample that pin? ________________________________________ From: piclist-bounces@mit.edu on behalf of Van Ho= rn, David Sent: Wednesday, August 23, 2017 11:16 AM To: Microcontroller discussion list - Public. Subject: [EE] Pic24FJ128 "Hair" on ADC pin What would cause sharp positive going "hair" on an ADC input? The ADC is reading ground immediately before, so the sample/hold cap should= be discharged, yet every time I sample I see this sharp positive spike on = the ADC input pin. I don't believe there is anything else happening with that pin, and it's al= ways an ADC input. - --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .