Time recovery of SPAD

[hjhjh]

I tried to test the SPAD model with components such as capacitors, diodes, resistors and switches representing incoming photons. The circuit structure I use is a passive quenching circuit, but the problem I encounter when simulating is that if the two photon clock pulses arrive adjacent to each other, the SPAD has not yet recovered after the quenching period, which will lead to signal errors. . Do you have any solution for this problem? I intend to use an active quenching circuit structure instead, but does that ensure that the time after quenching is enough for the SPAD to recover?

 

[dick_freebird]

If you know pixel-element background doping then you can get
lifetime. It's statistics from there on out, just how long a loose
carrier-pair will survive.

If you're trying to count single photons then you probably are
not that worried about high arrival rate. Or, it's a statistical rarity
that you might be prepared to tolerate by the time you get to
high "counts per frame" or whatever.

Because time-of-arrival is random, you can't "ensure" anything.
Just figure out how to spec and how to deal.

 

[D.A.(Tony)Stewart]

1. Characterize the SPAD's parameters, including its junction capacitance, breakdown voltage, and afterpulsing characteristics.
2. Design the active quenching circuit with a sufficiently fast comparator and quenching transistor to quickly stop the avalanche current.
3. Test the active quenching circuit with varying photon detection rates to ensure it can handle the event rate you expect in your application.