MC33887 motor driver

I ordered a couple of these boards for a new mini-sumo I’m building. The question I have is, why is there a D1 if there is also a ~D2? Can I PWM either one of those, or should I just PWM ~D2 and leave D1 not connected?

- Jon


The MC33887 provides two independent disable pins that will tri-state the motor outputs: D1 is active high and ~D2 is active low. You most likely will just want to use the one that is most convenient for your particular application.

The MC33887 datasheet addresses PWM speed control with the following two statements:

The carrier board includes this filter capacitor, allowing for PWM control via either of the two disable inputs. Note that the fault-status line will go low whenever a disable pin is active, making it only meaningful from a fault-detection standpoint during the enabled portion of the PWM duty cycle. The carrier board provides a pull-down resistor on the D1 line, allowing you to leave it disconnected. If you want to PWM D1 or one of the two motor inputs (IN1 or IN2), you will need to externally pull ~D2 high (the MC33887 internally pulls this pin low).

Our expectation is that the typical application will involve providing direction control via IN1 and IN2 and PWM speed control via ~D2 (while D1 is left disconnected).

- Ben

Cool, thanks Ben…

I’ve set up a page describing the project:

- Jon

Very nice design presentation. I’m interested to see how it turns out.

- Ben