I am using the LMD18200 H-bridge to drive a DC motor using a 20kHz PWM signal. This chip has a current sensing output which produces a current of about 377uA per Ampere flowing through the motor (recirculating currents are ignored). I would like to read this output at around 100Hz using a 3.3v ADC.
How can I simply and efficiently smooth out the current sense output ?
I know how to use a low pass RC (or RL) filter to smooth out a voltage source but I am not totally sure of how such a filter would behave in presence of a current source. Any help would be much appreciated.