I have the below circuit:
Forward diode D0002 - Datasheet SIJ series for reverse protection and C0001-C0004 capacitors for ESD protection.
Zener diode - Datasheet - 36V reverse breakdown.
BATT1 is the Vcc supply for certain ICs in my design whose absolute maximum ratings is 40V.
I have provided the Zener diode circuitry to clamp if the battery voltage goes above 36V (during transient ISO7637 pulses namely pulses 2a,3b and 5a.)
I have performed simulations in Simetrix with the proper models for each part, but the Zener diode circuitry is not clamping the voltage to 36V during these ISO7637 positive pulses. Why is it so? Is the Zener diode slow to respond or react to the input transient pulses 2a, 3b and 5a?
Please let me know like if there is something like Zener response time which makes it unable to do this clamping. Or what might be the reason?