sample and hold pulse source?

[Old Steve]

Note that this circuit now is non-inverting - a positive-going edge will produce a positive pulse.

ak

That's OK, one more 4069 gate cures that.

And I'm obviously still pretty rusty - should have thought of suggesting two inverting gates with added hysteresis resistors. I've done it myself in the past, long ago.

 

[Alec_t]

.... and if you want the post #20 circuit to have an inverting function, just take the output from the first inverter. The nice thing about that Schmitt trigger is that you can easily adjust the hysteresis (dead band) by choice of resistor values.

 

[Old Steve]

.... and if you want the above circuit to have an inverting function, just take the output from the first inverter.

I hadn't thought of that.

 

[AnalogKid]

The dead band window of hysteretic CMOS parts (40106, 4093, 74AC14, etc.) is not tightly controlled. While CMOS timer circuits frequently are more convenient than 555's, they also are much less accurate over temperature and part-to-part variations. Many CMOS parts have a "typical" value of 33% and a minimum hysteresis of 20%, and the resistor values in post #18 should deliver this. In fact, a circuit with non-hysteresis gates and external 1% resistors is more accurate, predictable, and repeatable than the integrated CMOS equivalent.

ak