5V tolerant input

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by 256Doofus on Wed Feb 08 14:36:01 MST 2012
Some question around 5V tolerant input on lpc11Cxx.

I do remeber that i read in the datasheet that for the input to be 5V tolerant, the powersupply to the µC need to be present. I am not able to find that anymore, so I can not pinpoint that. Can someone verify this?

If so, normaly you have 5V first, and use a voltage regulator to get f.eks 3.3V.
So 5V will be present first, and 3.3V will be present some time later.
The consequence is that you have violated the rule over....!?

Second, does someone know how the protection circuit is implementet on the pin?