• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 29 subscribers
  • Views 870 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV8801: Can I lock the shaft of the motor with this chip?

Nathan McKay
Prodigy 40 points
Part Number: DRV8801

I'm driving a door that slides left to right and right to left. When it reaches its end positions I want it to resist movement from gentle presses (obviously if they push on it hard enough it will no matter what.). I believe I would do this by locking the motor shaft. Can I do that with this chip?

  • 0
    TI__Guru** 114905 points
    Hi Nathan,

    The device can ground both outputs the motor shaft when it is powered up. Please refer to Table 1. The device can be set in brake mode (LL or HH).

    Depending on the motor, this may meet your needs. When the device is powered down, this feature is not available.
  • 0 in reply to Rick Duncan
    Prodigy 40 points

    Thank you Rick. Kind of. I have more questions. If the motor is in brake mode, and I move the motor, the back emf generates current, and my load is just a short through ground (or supply), so I would likely break my circuit, correct?

  • 0 in reply to Nathan McKay
    TI__Guru** 114905 points
    Hi Nathan,


    It depends. As long as the voltage specs are not violated and the thermal remains with acceptable limits, this device should work.

    The current is recirculating through the low or high side FETs so there should be no problem. If the device temperature rises enough to disable the FETs, the motor can cause the VM voltage to increase so the bulk caps will have to accept the current and keep the voltage with device limits.

    I would recommend using the low side FETs because the RDSon of the FETs are lower.
  • 0 in reply to Rick Duncan
    Prodigy 40 points

    Thank you! I learned a little more about MOSFETs as a result of this.