>>
>>As someone said, it SOUNDS like latchup. This occurs when a parasitic SCR
>>formed with the gate transistors and the substrate layer is biased on. Once
>>on it stays latched on until power is removed. Taking pins outside their
>>design limit voltages is a good way to cause this. Hence the above
>>questions.

Additionally, the chip has to cool before it will behave normally again, if it ever does.

This is a good illustration of why you should never let the protection diodes conduct!

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