I would like to measure tree signals by using a ucontroller.
the signals are between
- -5V to 5V
- 0V to 2V
- -20V to 20V
The frequency of the signals are between 1MHz and 5MHz. The ADC range is between 0 and 3V.
I built the following simulation, where I am dividing and shifting the measured signal:
I have the following questions regarding the circuit:
- How should I choose the resistors in the voltage divider and OP-AMP gain?
- How can I make 'dynamic' voltage divider? I mean controlled by microcontroller? I checked the analog switches in the TI website but I am not really familiar with those switches.
- How can I protect the circuit from over voltages?