PWM crosstalk into Analog-in?

Projects General Guidance
1

Dear all,

I want to use the Arduino UNO in a project to reanimate an older measurement instrument (photometer) and to connect it to my PC.
Aside from several digital switches that I will implement with MOSFETS I need

  • two Analog Outputs 0-5 V to control the instrument (I will use two Arduino PWM outputs and flatten them into "true DC" by active RC filters using OpAps) and
  • one Analog input to acquire the measurement data (DC, 0-15 V range, I am also thinking of wiring a 12-14 ADC to The UNO to have a bit more resolution).

My question to the Arduino community:
As the Arduino only has PWM outputs to build the DC from as described above, I am a bit concerned that the PWM signals leak into the AIn signal and creates a noise problem there?

Has someone tried this? How significant is a PWM crosstalk into the analog inputs?

Many thanks
Holger

2

How significant is a PWM crosstalk into the analog inputs?

The analog inputs of what? The Arduino? There is no relationship between banging a digital pin on and off and the analog-to-digital converter.

3

Thanks for your reply Paul, I thought I read this somewhere on the web.
This is encouraging.

Holger