uPSD3312D - 5V IO tolerance for P1 no more available?

daxenberger · ‎2005-08-12

Posted on August 12, 2005 at 15:01

daxenberger · ‎2011-05-17

Posted on May 17, 2011 at 12:05

Hi,

I have recently downloaded uPSD33xx datasheet V4.0. I have just finished a design based on the previous datasheet and I stumbled over important changes in specification although they are NOT mentioned in the revision history of the last version of the datasheet.

Port1 seems not to be 5V IO tolerant anymore! I guess this is because of the internal ADC. I am using P1.0 and P1.1 as analog input, but I am using UART1 on Port1 as well. As I am using a 5V Maxim 232 transceiver part this is a problem now.

Maybe someone from ST could give me a hint.

Why isn't that mentioned inside the datasheet? This is not good behaviour!

Regards,

Stefan

gbillard9 · ‎2011-05-17

Posted on May 17, 2011 at 12:05

The ViH of the max232 is low enougth to be driven by a 3.3V bus. I make an application with tah an no problem occurs