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Topic: opinions sought on level-shifter design - nasty or nice. (Read 901 times) previous topic - next topic

winner10920

It would matter which can handle more current,  i imagine neither are current limited so the 5v will source current to the 3.3v until one gave out

oric_dan

Quote
It would matter which can handle more current,  i imagine neither are current limited so the 5v will source current to the 3.3v until one gave out


Well, output pins are always current-limited, but you wouldn't want to try connecting 5V high
output to 3.3V low output, or vice versa.

I suspect a better designed [ie, non-lethal] level-shifter will have a 1K series resistor in the data
path.

winner10920

In a sense they ate current limited but not to the point where the short circuit current is limited to a safe value, and with no short circuit detection something is bound to pop first,

oric_dan

Sure seems to be difficult to come up with a bulletproof level-shifter ckt.

winner10920

Thats not hard, its coming up with one that is simple, easy, effective, and cheap that is difficult

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