Hi everyone!
I would like to know what happens when the signal input in a PIC16F84 is a sinus wave. How does this micro see that input if there is not a comparator? How is it modified then?
Thank you!
- posted
16 years ago
Sinus Input
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- posted
16 years ago
Sine wave...huhhh.. :P
If you're putting a sine wave at a digital input (within the digital input range) then the PIC will see a digital high or low depending on the sine voltage level. See the pic datasheet for the logic voltage levels. D from BC
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- posted
16 years ago
lol! Sorry!! Sine wave, that's it :-P
Thank you a lot!!!
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- posted
16 years ago
Did I understand well?
We know that RA4 pin from PIC16F84 works (in input mode) as a Schmitt trigger (ST): if VDD=5V, VSS=0V and the input signal in RA4 is a sine wave (2V p-p,
0 offset)... The result is a 0V signal all the time? Or due to the 0V in VSS the signal would be a squared wave with +5V when sine>0 and 0V when sine- Vote on answer
- posted
16 years ago
The result of this will be a damaged PIC input pin. You should not pull the input pin below Vss. See section 9.0 of the data sheet, absoloute maximum rating for voltage on any pin with respect to VSS is -0.3V to Vdd+0.3V
Bob
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- posted
16 years ago
yes and clamping with a silicon diode will still result in a broken PIc as (IMS) they don't like -.4v... so if you insist on doing it like this, clamp with a germanium diode (0.2V) which is starting to get expensive - pass the signal into the pic thru a silicon diode?