9 Replies Latest reply on Feb 11, 2021 12:20 AM by dougw

    Issues With MOSFET bridge, DC motor 24V 200W


      Hello everyone,

      I have been working on a project to drive a 200W 24V motor that gets a continuous drive current of about 7-8A. The idea is to run the motor in forward and reverse direction interchangeably much like a car viper. The time for forward and reverse is about 20seconds each.

      I want to use 4-N channel MOSFETs for this and use a discrete driver.

      Mosfets used - STP55N i.e. 60V 50A

      Input supply - 24V

      PWM input - In-1 and In-2, a signal on one of the inputs will run the motor in one direction and vice versa.

      Bootstrap Capacitor - 10uF 50V


      Issues -

      1. The circuit is working i.e. motor is getting turned on in both the direction but upper MOSFETs are getting heated upto 70degree within few minutes.

      2. Is there an issue with the bootstrap circuitry?