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Max current per leg in a BLDC application for 8412 driver

Other Parts Discussed in Thread: DRV8412, DRV8312

We are looking at using the 8412 to control a stepper motor OR a BLDC motor depending on the application.  The spec says you can drive 3A x 2 channels for stepper motor application.  What about BLDC/3 phase application?  Is the current limited by the package or by the transistor limitations in a half-bridge?  Can we exceed 3A per phase with BLDC?

Thanks

Andy

  • Andrew, the current limitation comes down to thermals. The datasheet mentions you can also drive 6A peak current. The device has integrated over-temperature protection that's 150C typical, so you might hit that if you drive too much current (depending on your PCB's dissipation ability and your ambient temperature).

    Best regards,
    RE
  • Hi Andrew,

    There is one additional point to make. Using the DRV8412 to drive a BLDC motor may not work.

    The DRV8412 sets each pair of outputs into hi-z (RESET_AB and RESET_CD), where the DRV8312 allows control of each individual output (RESET_A, RESET_B, and RESET_C).

    Please keep this in mind when evaluating your needs.