Hello,
I'm having some issues with an input on my PIC ignition project. I had a 2N4401 setup as a NOT gate to provide an input to the PIC 16F630 from a 3v or 5v signal. Problem is, the input signal is a 2ms pulse, which I believe is faster than the 2N4401 could see in a NOT configuration, as I have been unable to find data on it's performance as a NOT.
So, I swapped that with a 2N7000, no change. Now it's unstable and the 2N7000 will oscillate just by you touching the gate.
I have attached a sketch of how my input is, and was wondering what your recommendations are. I was going to put a 10K pull-down on the gate to prevent the oscillation, but sensing a 2ms pulse will still be an issue.
Thank you,
Alex
I'm having some issues with an input on my PIC ignition project. I had a 2N4401 setup as a NOT gate to provide an input to the PIC 16F630 from a 3v or 5v signal. Problem is, the input signal is a 2ms pulse, which I believe is faster than the 2N4401 could see in a NOT configuration, as I have been unable to find data on it's performance as a NOT.
So, I swapped that with a 2N7000, no change. Now it's unstable and the 2N7000 will oscillate just by you touching the gate.
I have attached a sketch of how my input is, and was wondering what your recommendations are. I was going to put a 10K pull-down on the gate to prevent the oscillation, but sensing a 2ms pulse will still be an issue.
Thank you,
Alex