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Original question:

DRV8886AT: Cannot drive above 600mA

DRV8886AT: DRV8886AT current

user6151353
Prodigy 80 points
Part Number: DRV8886AT

can the DRV8886AT  drive 1.5A rated Bipolar Stepper Motor？

the output current of the DRV8886AT is peak current？

  • 0
    TI__Guru** 114905 points

    Hi user6151353,

    The DRV8886AT can drive a 1.5A rated motor, assuming proper thermals on the PCB.

    What is the desired RMS current setting? If it is 1.4A or less (RREF resistor is 20kOhm or greater), the device can drive current this with proper thermals

    There may be a problem when using non-circular 1/2 step and holding at high currents.

    The DRV8886ATEVM is available for evaluation.

  • 0 in reply to Rick Duncan
    Prodigy 80 points

    Dear Rick


    Thanks for your reply.


    But I still have some doubtful question.Pls give me some guidance.
    The datasheet of DRV8886AT describes that the full-scale current is 2A（Max value）or 1.4A RMS current(Max value）.


    My question is as below:
    1. My understanding is that the driving ability of  IC is 1.4A RMS current(Max value）so it seems that the IC can not driver the 1.5A  rated motor.
    2. What is the Output parameter of xOUTx Pin during working on the 1/16 microstepping? Is it Full-Scale Current or RMS Current？

    Best Regards,

  • 0 in reply to user6151353
    TI__Guru** 114905 points

    Hi user6151353,

    But I still have some doubtful question.Pls give me some guidance.
    The datasheet of DRV8886AT describes that the full-scale current is 2A（Max value）or 1.4A RMS current(Max value）.

    Full scale current is 2A max. This equates to 1.4A RMS current when the motor is spinning.

    My question is as below:
    1. My understanding is that the driving ability of  IC is 1.4A RMS current(Max value）so it seems that the IC can not driver the 1.5A  rated motor.

    The IC can drive a 1.5A rated motor, but only up to 1.4A RMS current. If you need 1.5A RMS current, the device is not able to do so. 


    2. What is the Output parameter of xOUTx Pin during working on the 1/16 microstepping? Is it Full-Scale Current or RMS Current？


    Please refer to Table 3 of the datasheet. At each step the current is regulated to x% of full scale current.
    For example:

    If the full scale current is set to 2A, the current at steps 1, 17, 33, and 49 of Table 3 will be 2A in one output and 0A in the other. The current sine wave will be 1.4A RMS.