ADC Vref stm32f4 disco

fiulala · ‎2015-07-21

Posted on July 21, 2015 at 13:42

Hi,

I want to know how could I get a range 0-5V in ADC. I know that normally it's from 0-3V. It's enough connecting 5V to Vdd?

Thank you

raptorhal2 · ‎2015-07-21

Posted on July 21, 2015 at 14:55

Absolutely do not connect 5V to Vdd.

Rescale the input to 3 volts with a resister divider pair or a rescaling op amp. The op amp may be necessary for short sampling times.

Cheers, Hal

fiulala · ‎2015-07-21

Posted on July 21, 2015 at 15:37

Ok. Thank you for the advice.

There is no way

that I can get a

range of 0-

5V

on ADC? The only way is rescaling the input to 0-3V?

raptorhal2 · ‎2015-07-21

Posted on July 21, 2015 at 16:32

Read the data sheet section on Absolute Maximum Ratings and the pinout table notes on 5V tolerance (FT) for analog inputs.

The ''any other way'' could be an external 5V ADC chip with a digital interface to the disco.

Cheers, Hal