Need help with falling edge decay/delay circuit

Thread Starter


Joined Feb 21, 2013
Hello i'm trying to think of a relatively simple (small board) circuit to add a delay to the falling edge of a signal only. Imagine the input is a 5V 200ns square wave. I would like the rising edge to be fast and on-time but have the falling edge either be delayed by 300ns or have a slow RC-like decay. A single IC could be used if necessary. Thanks for your help, im struggling with this one.


Joined Apr 24, 2011
No need to go to an IC if an RC will do: for large signals (5V is probably large enough) just put a diode across the resistor. Charging the cap goes thru the diode and is fast. Discharging goes thru the resistor and can be controlled.