Are M9S12XDP512MAL I/O pins 5Volt Tolerant?

[pablogiudice]

Hi everybody!

I'm working with a M9S12XDP512MAL and source voltage is set in 3.3V. I'd like to interface it with an LCD display that works with 5V. As the communication has to be bidirectional, the microprocessor will be able to send data to the display but I dont know what'll happen when sending data back from the display to the MCU. In datasheets I haven't seen that IO pins are 5V tolerant but it's not clear about what happens when connecting a 5V output.

Thanks in advance !

PG

[kef]

No, it isn't. When MCU is powered from 3V, injection current will flow from your 5V source via MCU internal clamping diode to 3V supply rail. Check the specification what are injection limits (per pin and total). You may try using current limiting resistors and maybe some voltage limiting devices, but why don't you want to power S12XDP from 5V?