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  1. P

    H-Bridge MOSFET blowing up

    I can also confirm that flyback diodes + 22ohms resistors in the gates of the MOSFETs didn't work either. Power supply was decoupled using 2x 4.7uF/50V and 100nF ceramic capacitors. :(
  2. P

    H-Bridge MOSFET blowing up

    I can confirm that flyback diodes didn't help :( I used 4 1N5819 for each HBridge but MOSFETs are still dying after some seconds
  3. P

    H-Bridge MOSFET blowing up

    Yes, actually they are on a robot and the mass of the robot is the same for both cases so they are supposed to be equally stressed. PS is the output of a DCDC converter and it's 12V. VCC is the output of a 3.3V LDO . I have separate ground planes and they are connected using just one track...
  4. P

    H-Bridge MOSFET blowing up

    Oh okay, I should have explained it better. Sorry. The sketch I posted, was showing a whole PCB for driving two motors. When I used that board to drive two motors using 4 different signals: L_PWM, L_DIR, R_PWM and R_DIR, it worked just fine. However, when I drove the two motors with just...
  5. P

    H-Bridge MOSFET blowing up

    Hi Thanks steve once again for your help. Won't these resistors introduce a delay in the transition? I'm not sure if I understood this well. The two inputs of the 4427s are used to drive 4 gates so if i'm getting you right, I would need to use two 4427s to drive the 4 gates tying...
  6. P

    H-Bridge MOSFET blowing up

    Here is the schematic: Regards
  7. P

    H-Bridge MOSFET blowing up

    I don't have the schematic handy right now but I'll try to upload it later. Anyways, the board is the same for two version but the logic signals for the wrong case are connected together for both motors (ie, motors run at the same speed). In the good version, I drive the two motors from...
  8. P

    H-Bridge MOSFET blowing up

    Thanks steve for your speedy response! This circuit is working just great with no body diodes if I drive two motors with 2 different signals for each motor. This was the reason why I didn't use diodes across the mosfets. However if I drive two motors with the same 2 signals for both motors...
  9. P

    H-Bridge MOSFET blowing up

    Hi, I am using a MOSFET H-Bridge IC (ZXMHC3F381N) driven by a MAX4427 MOSFET driver IC to control a motor. Actually I've got two pairs of those ICs to control 2 motors using the same signals from a microcontroller and, for some reason, the ZXMHC3F381N blows up after a while. VDD is 12V...
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