[sdiy] Comparator high frequency hysteresis

[Rutger Vlek]

Dear all,

I'm working on a comparator circuit that is driving a switch, but I'm having difficulty stabilizing the comparator output while keeping it accurate (to the point where it flips state).

I've taken precautions in the layout for stray capacitance, and added hysteresis to the circuit. However, I was hoping to add additional hysteresis for high frequencies specifically, since I only need the comparator to work on audio range and CV range signals.

I've read TI applications notes about adding an additional capacitor across the feedback resistor, seen other ways of adding capacitance (that were criticized by experts) and I've read about Tony Allgood's 'transistor starving trick' in the Oakley Sound dual comparator 2 documentation. However, no idea how he implemented that.

What are your recommendations/experiences for a precision comparator circuit in this respect?

Rutger