I have on my circuit an integrated circuit (IC) that has been destroyed by some event. After the event, the component's Vcc pin was shorted to GND inside the IC.
After measurement, it appears that there is a surge spike on the Vcc (5V) net. Here is a screenshot of the measure I made on Vcc:
It shows that the spike can rise up to ~15V, but I have seen it over 20V. The half-wave last for approximately 1 µs to 1.5 µs.
The datasheet of the destroyed IC gives an absolute maximum value for VCC of max 6V. This is largely exceeded here.
To protect the ICs, I have thought to use a TVS diode such as SMAJ5.0A/CA (5V stand-off voltage). But such a diode have a minimum breakdown voltage of 6.4V, typical 6.7V, which is sill over the absolute maximum ranking for VCC of my ICs.
Will this protect the ICs, despite that the fact that we are still a bit higher that the spec ?
Do you know know an other mean of protection for the ICs ?