Fellow Timenuts:
I'm trying to square reality with the modeling that I did, and nothing makes sense. When I modeled the result of just my 2.4K resistor with the caps and resistor the PIC datasheet says it has in it, there's no relationship. The model says I'll get millivolts out. Here's how I calculate what I'm actually getting: ADC VRef is 2.5V 10-bit ADC = 1024 positions Max ADC from TIC = 975 975/1024*2.5 = 2.38V Max TIC value Min ADC from TIC = 293 293/1024*2.5 = 0.715V Min TIC value A range of 0.715V-2.38V is totally outside my expectations. The only way I can get close to these values is if the internal CHOLD in the PIC is only a fraction of the 120pf they say it has - say 20pf. Any thoughts would be appreciated. Bob - AE6RV _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
