Quick PIC16F874A question
I am looking at this PIC and notice in the pinout description that on PortC, the buffer type is a Schmitt Trigger, but the description classifies it as a digital I/O. I just want to make sure that these pins will work like a TTL for on/off, unlike the 628A where A.4 is an open-drain and requires a pullup resistor.
I know I've answered my own question, but I just want to be 100% positive.
Thanks,
Tony
Re: Quick PIC16F874A question
a Schmitt Trigger is a type of input circuit and therefore refers to the input buffers for the port , portc on that chip has no open drain pins .
porta.4 however is open drain
Re: Quick PIC16F874A question
But it will work like a TTL I/O, will it not? The digital I/O comment I am questioning, even though it is a Schmitt trigger.
Re: Quick PIC16F874A question
if the chip is powered from a 5 volt supply then as a input device its logic level thresholds will be similar to any ttl device with a Schmitt trigger input stage and therefore be ttl compatible and as a output its drive capability is well within the ttl family fanout range.
google Schmitt trigger if you don't understand . (Schmitt trigger is a input feature it has no relevance to the output stage at all)