Driving two MOSFETs with one driver chip

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homeinsandiego

Joined May 28, 2014
2
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.
 

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BobTPH

Joined Jun 5, 2013
2,266
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
 
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