Other Parts Discussed in Thread: ISO5452,
I'm working on an application which requires a 2.5V desat threshold with 2us blanking time. I'd ideally like to use a Zener diode to set the threshold as I would otherwise need a very large string of rectifier diodes in series.
However, I've done an exhaustive search of various Zener diodes and cannot find any which reach their knee point at 500uA (desat charge current of the ISO5452).
I've seen some replies on here which suggest using Zener diodes to adjust desat voltage - can you recommend a particular series which is suitable for the very low current in this application?
FYI - I've also considered using a ~10k resistor to adjust the desat threshold. The disadvantage with this approach is that it significantly extends the desat blanking time due to the RC time constant.
I end up needing a 33pF blanking capacitor using this solution and this makes me very concerned about noise immunity - my switching frequency is up to 100kHz and bus voltage is 1200V.