Other Parts Discussed in Thread: TINA-TI
Hello,
Our goal is to use the SN74HCS74 as in the typical application, as a Device Power Button Circuit. we would like our debounce RC circuit to have a time constant of around 50ms. Thus we would like to have R2 as 10k and C1 as 4.7k. unfortunately, the circuit does not work in this configuration, because the voltage drop is too great, as outlined by issue #2
We are experiencing unusual behavior while simulating this circuit.
1. the output is behaving erroneously whenever C1 is greater than ~1nF
2. the CLK pin is drawing ~400uA @2v which is a lot more than the 100-1000 nA @6v specified by the datasheet
Attached is our schematic and LTSPICE files.
crop: