I need to design a buck converter (controlled by pwm using feedback) for a 24V dc motor under no load. The buck converter output can be controlled to vary between 15v and 24v. I understand that in order to choose a correct inductor value to ensure CCM operation, I need to know the load current, and that the lower the load current, the greater the required inductor value as per this design formula:
The nominal voltage for the motor is 24V and there is a rated current of 130 mA. The spec also states that for 24V motor models the maximum no load current is 50mA. So for my design what output current should I be using to choose the inductor value? 50mA is the maximum no load current meaning that it could technically be less than 50mA so I think it would operate in DCM if I designed for this value. And I don't understand how the output current would vary when supplying less than 24v to the motor (since the voltage supplied to the motor could be as low as 15v). My intuition is that the current draw would be greater, so I should be considering the worst case scenario, 24V, but maybe this is not true.