Hello,
I am confused about the maximum "I/O voltage tolerance" rating of this part. It appears that the forward voltage drop of the internal diodes is around 0.7 V (from my breadboarding tests), while the absolute maximum voltage the datasheet suggests to put on the I/O pins is Vcc+0.3 V. This is not enough to make the diodes conduct. Is this suggesting that short voltage spikes are acceptable, while constant overvoltage past Vcc+0.3 V is not recommended?
Thank you,
Sam
Hi Sam,
Is this suggesting that short voltage spikes are acceptable, while constant overvoltage past Vcc+0.3 V is not recommended?
Your understanding is correct. Our ESD diodes are designed to protect from transient events (nS - µS pulse durations).They are not built to withstand being broken down over a long period of time from a static DC voltage. Once the diode is broken down, it generates a significant amount of heat as current goes through it. This will eventually cause thermal failures.
This is why we recommend that you only apply static DC voltages across the diode that are at or below the rated Vrwm, which in this case, is 5.5 V.
Regards,
Sebastian
