Interference of DAC output and the PWM

manoritesameer · ‎2014-08-12

Posted on August 13, 2014 at 07:21

Hello,

I am generating a signal which goes to output of the DAC, but unfortunately when I use the PWM module of the system the PWM signal frequency distorts the signal generated by the DAC.

Can anyone tell me what is the problem and if there exist a solution.

Regards

frankmeyer9 · ‎2014-08-14

Posted on August 14, 2014 at 10:37

You did not provide much (any) information about schematics, layout and component placing, which makes it hard to guess. Naming the MCU type would help, too, albeit the DAC implementations seem the same across the STM32 family.

However, the DAC has a high output impedance, especially in non-buffered mode. Switching circuitry nearby, or non-optimal power supply/decoupling can easily affect the DAC output.