Diodes purpose in this circuit?

[Roman]

Hi. Sense pins in this schematic are used with diodes. Anyone can explain? And what diodes will work here. No info in datasheet.



Thanks,
Roman

 

[(*steve*)]

They champ the input voltage a diode drop above Vcc

 

[(*steve*)]

Oh, they are drawn as schottky diodes.

 

[hevans1944]

You need to protect the inputs of the ADC in the MCU from overshoot, caused by possible parasitic LC ringing in the inductance of the motor winding. High-speed reverse recovery Schottky diodes are necessary because of the high frequency pulses associated with PWM motor current. Not much current is involved, because of the high impedance of the voltage divider feeding the ADC inputs.