Driving two MOSFETs with one driver chip

Discussion in 'General Electronics Chat' started by homeinsandiego, May 28, 2014.

  1. homeinsandiego

    Thread Starter New Member

    May 28, 2014
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    I have a TI motor controller that uses the DRV8301 3-phase Pre-Driver motor chip to control three H-bridges. I want to use the one DRV8301 to control two sets of motors. The DRV8301 has six outputs, GH_A, GL_A, GH_B, GL_B , GH_C and GL_C where each H-Bridge (two MOSFETs in series) use a high and low signal. The three phases of the motor are A, B and C. See attachment.
    So I took the working motor controller and soldered wires on the traces that go from the driver to a 1 ohm resistor that connects to the MOSFET gate.
    Turned on the motor controller and a fault on the GUI occurs. I calculated the drive current required and it is below the max. I have a feeling that there a timing issue due to different capacitance of the MOSFETs.

    Any suggestions welcome.
    Thanks in advance.
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
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    It may not like what it sees from the 2 motors. Try it with one.
     
  3. homeinsandiego

    Thread Starter New Member

    May 28, 2014
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    I have separate H-bridge circuits controlling each motor. What is common is one driver leg to the gate of two MOSFETs.
     
  4. BobTPH

    Active Member

    Jun 5, 2013
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    This is a stab in the dark, but how long are the wires between the two H-bridges? It might the extra inductance of these wires that is causing a problem.

    Bob
     
  5. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Are they BLDC motors or just AC motors?
    The driver has over current detect. What is done with it?
     
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