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asymmetric pulse delay (pulse extender)

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aniccame

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I am working on a circuit that uses four phases of a 74HC4017 johnson counter and 2 x 2 74HC32 OR gates to create two square waves phase shifted by 90 degrees.

It is almost perfect, except on the OR gate output, I need to output to stay high as each input goes high. However, due to propogation delay in the Johnson Counter and wiring, there is a very short amount of time when the output of the OR gate goes low. It's so brief it isn't even registered on my 20 MHz scope. However, I need to eliminate it for my application (driving IR2110 mosfet drivers).

The circuit is operating between 10 Hz to 1 MHz.

I need the first pulse that goes into the OR gate to be extended by around 100ns or 200nS. I don't want to delay the rising edge of the pulse, just delay the falling edge.

I think I have a resolution that I stumbled across by using a diode, resistor, and schmitt trigger. I will post it here if it works.

If anyone has any ideas or questions they would be greatly appreciated!
 

This has been resolved.
I needed to use higher value power supply bypass capacitors in the circuit.
 

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