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Interfacing STM32F205RBT6 to max232

aamirali641989
Associate II
Posted on August 01, 2014 at 16:04

Hi,

Can I interface directly max232 to STM32F205RBT6.

I have given 5V to VCC of max232 & 3.3V to vcc of STM32.

1. In datasheet of max232, it is given that Vih = 2V. So my 3.3V signal from STM32 will serve the purpose of txd

2. In case of rxd, 5V signal will come from max232 to STM32. Are STM32 pins are 5V tolerant in case I configured them for uart?

3. I have place 150ohm resistor each in between txd & rxd connections of both IC.

1 REPLY 1
Posted on August 01, 2014 at 16:15

If one was thinking a

http://datasheets.maximintegrated.com/en/ds/MAX3222-MAX3241.pdf

might have been a better part choice.

Some pins are Five Volt Tolerant (FT), as identified on the Data Sheet, for the F2/F4 this would be most non-ADC pins, but best to check. PA9/PA10 should be safe.

VIL, VIH, VOL, VOH should be sufficiently accommodating.

I wouldn't bother with series resistors here.
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