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Peak "detector" to detect TIMING of peaks

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I've been wondering what sort of circuits would be used for this application, but can't find them by searching because the obvious name "peak detector" is ofcourse already applied to circuits which hold the level of a peak.

I'm looking to produce a sharp rising edge (dropping back down after some chosen short* interval) when an incoming analogue signal goes through a (local) maximum**, something which will trigger this pulse just as a rising signal starts to become a falling signal again (I can low-pass filter this incoming signal enough to avoid noise peaks giving false triggers).

*exact time to be decided, but somewhere < 20% of the typical time usually expected as the shortest plausible between peaks
**any event where a rising signal has a change in dV/dt switches sign such as to have the signal start fallig again

I'm looking to do this with generic ICs mostly, op amps and that sort of thing, not specialised single purpose chips and not building up from individual transistors either.

Can anyone suggest good search terms to find this sot of circuit, given that the word "detector" is pretty much reserved for level holding circuits rather than ones which make a logic level transition at the time of the peak.


EDIT: I've just realised I could probably do this with a differentiator circuit feeing in to a zero crossing detector, but is there a better way?

David Hess:
A differentiator can be used to reveal the peak of a pulse when its output crosses zero, however differentiators are prone to noise.

A differentiator is pretty much the definition of this circuit. What you're trying to detect is the slope of zero, either by measuring the slope directly or by some indirect technique such as a peak-hold circuit followed by a comparator to detect when the present value is less than the peak.

It's problematic, as David says. You can help, bu first low-pass filtering and then differentiating. But that introduces delay. Such are the compromises you have to make when designing real-world circuits.

Is there a nice way to make a zero crossing detector which only triggers on a rising edge? So one can check the differentiator's output to detect only maximums of the original signal, not minimums? Would one have to feed in to another differentiator to take 2nd derivatives, or is there a more straightforward way? What do microcontrollers actually have inside where they've got pins which can give an interrupt specifically on a rising/falling (delete as apropriate) edge but not a falling/rising (vice-versa) edge?

MCU interrupt can be triggered by only one specific edge.


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