> I stress tested our IO level shifter chips for short circuit robustness. Leaving the outputs shorted hard to the opposite rail overnight did no apparent harm

> I stress tested our IO level shifter chips for short circuit robustness. Leaving the outputs shorted hard to the opposite rail overnight did no apparent harm (bypassing the protection resistors), other than getting the chip nice and toasty for the duration of the test. That's impressive! Thanks for the reply, sounds like I can be a bit less cautious without fear of blowing things up.