Re: 5V to 3.3V UART conversion

Spehro Pefhany wrote:


Usually the source voltage is not that important if the current is
limited (there is a protection network between the input and Vdd).
Yes, it can be reliable.

I've fallen over by simply using a resistor between a 5V system and a 3.3V system... the small current, combined with the almost zero load on the 3.3V side, was enough to drive the 3.3V up to about 4V- the regulator couldn't sink. No damage done, but the flash on the MSP430 wouldn't program, and red face when I had to add a zener to make it work.

Paul Burke
.

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