• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 31 subscribers
  • Views 250 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

DRV8832: PIN2-Current Sense feature

Cherry Zhou
Mastermind 22235 points
Part Number: DRV8832

Hi team,

Here's a project required to drive the device and single cell powered, DC brushed reduction motor. 

1) PIN2-current sense limits the operating current of the motor, can it help with high instantaneous currents? If PIN2 is connected directly to ground, is the current limit turned off (i.e. no current limit) or is the current limited to within 1A?

2) If the operating current of the motor fluctuates between 0.8A and 1A and occasionally the instantaneous current reaches 1.2A to 1.5A, what is the recommended setting for the current limiting resistor?

3) Based on point 2, how to select inductors if it's required to connect them in series on the PIN3-OUT1 line?

Could you help check this case? Thanks.

Best Regards,

Cherry

  • 0
    TI__Mastermind 37683 points

    Hi CHerry,

    Cherry Zhou said:
    1) PIN2-current sense limits the operating current of the motor, can it help with high instantaneous currents? If PIN2 is connected directly to ground, is the current limit turned off (i.e. no current limit) or is the current limited to within 1A?

    Yes. the driver will limit any inrush current or sudden current transients as long as it is not above the OCP threshold for longer than the OCP deglitch time. Otherwise, this will cause an OCP fault. If PIN2 is connected directly to GND, current regulation will be disabled but OCP will always be enabled.

    Cherry Zhou said:
    2) If the operating current of the motor fluctuates between 0.8A and 1A and occasionally the instantaneous current reaches 1.2A to 1.5A, what is the recommended setting for the current limiting resistor?

    The current should be limited to the RMS current of the motor. If the nominal operating current (RMS current) of the motor is 1A, the current limit should be set to 1A.

    Cherry Zhou said:
    3) Based on point 2, how to select inductors if it's required to connect them in series on the PIN3-OUT1 line?

    It all depends on the purpose of adding the inductors. If it is to slow down the current transients, the inductance should be chosen such that the current has enough time to rise to its final value before the PWM cycle ends.

    Regards,

    Pablo Armet