We are using the VNH2SP30 to control a DC motor (follow a motion profile closed-loop). In principle this works fine, however for modeling the dynamic behavior of our controlled system (the VN2SP30 + motor + load) it would be great if could active break (instead of coast) during the “0” value on the PWM pin.
Is it possible to control the braking/coasting mode for the VNH2SP30 during the “0” value on the PWM pin?
Or is there perhaps another pololu H-bridge that would allow this behavior ?
The MC33887 motor driver can drive a motor by alternating between power and brake. This is achieved by PWMing one input while holding the other input low. However, the MC33887 can only deliver a maximum of 5 A (~2.5 A continuous), which is much less than the VNH2SP30. How much current do you need?
You might be able to achieve a similar result by using this same technique with the VNH2 (leave the PWM line permanently high and PWM one input while holding the other fixed), but I don’t think this is a typical mode of operation for the VNH2. The VNH2 may not be able to handle switching on its direction inputs anywhere near as quickly as its PWM input, which would restrict you to using low PWM frequencies. Please see the VNH2 datasheet for details (e.g. timing diagrams).
Thanks for your reply!
We will probably try the MC33887 for testing. We may need some more current in our actual setup but for testing the 2.5A continuous should work.