What is the correct PWM frequency for DC motors?

How does one decide on the correct frequency for a brushed dc motor? From what I have seen most folks recommend ±100Hz for simple (open loop) applications? :-? Others say it must be above audible range?

Also is there a ‘best practise’ wave form to use on the duty cycle signal?

Any info or links appreciated. :slight_smile:

The best frequency depends on a number of factors, such as the inductance of the motor, the switching speed of the driver transistors (or MOSFETs) and whether the audible whine is a problem. So, it’s hard to specify a single “best” frequency!