VNH2SP30 PWM Not Working with Motors

Hi everyone, recently I have had problem with the VNH2SP30 motor drivers. So far, I’ve been testing them with Faulhaber 12V 2342S012CR motor but there does not seem to be a proper linear relationship between the PWM value (set by ATmega328p) and the output voltage (with motor attached). For instance, a considerable change in output voltage is recorded (around 2V) when the PWM value increases from 10 to 20. But, when it reaches around 110, the increase in output voltage starts to peter out and a large PWM increase is needed just to increase the output voltage by 0.1V.

This has made it really difficult for me to attempt to control the motors. However, when I unplugged the motors, the PWM seems to be working just fine. Whereas, when I plug my motor in, the voltage spikes and increases suddenly. Could any of you guys help me please?

Thank you so much!


In general, it is not surprising that adding a motor could change what you are measuring at the output of the driver. What are you doing with the INA, INB, DIAGA/ENA, and DIAGB/ENB pins? What two points in the circuit are you measuring the voltage across?


Hi, I’ve resolved the problem. I figured that measuring the current draw of the motor and calculating the power per pwm value is more effective.