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DRV110: Ipeak and Ihold setting

David Park
Expert 6340 points
Part Number: DRV110

Hello team,

Can Ipeak and Ihold set to 1A, 330mA?

In the datasheet, current is set by Vref and Rsense and Vref is set by resistor.

Recommended resistor value is from 66.67k~2M and 66.67k~333k and if Rsense is 1Ohm, maximum peak is 900mA.

If Rsense is below 1Ohm(for example 0.5Ohm), can Ipeak and Ihold set to 1A and 330mA?

Thanks.

  • 0
    TI__Expert 6330 points
    Hi David,

    I have notified our expert regarding this topic. Please expect a response by 10/25/18.

    Thanks,
    Aaron
  • 0
    TI__Intellectual 1965 points

    Hi David,

    The selection of Rsense will proportionately scale the peak and hold currents, and there is no limitation to the range of Rsense values the DRV110 supports. Thus, Rsense can be set to 0.5 Ohms to allow Ipeak and Ihold to be 1A and 330mA.

    Best,

    Grant

  • 0 in reply to Grant Falkenburg
    TI__Expert 6340 points
    Hi Grant,

    Thanks for your reply.
    I want to specify my question.
    Below is test condition.
    Fault: 2/30
    Duplication: always
    Setting: 0.59Ohm sensing resistor, 51.1kOhm Rhold
    Symptom: With power on, no operation but it is operated with contact probe or tweezer at Hold pin.
    When 0.39Ohm sensing resistor, 77.7kOhm Rhold, issue is closed.

    Question
    1. no recommendation of 30k~55k at Rpeak/Rhold is for only avoiding default setting?
    2. Can above symptom be explained?
    3. For 1A Ipeak, 330mA Ihold, what is the recommendation for Rsense, Rpeak, Rhold?

    Thanks.
  • 0 in reply to David Park
    TI__Intellectual 1965 points

    Hi David,

    While both of your settings provide 330mA according to the I_HOLD formula, the formula is only valid for R_HOLD between 66.7 kOhm and 333 kOhm. Additionally, the transition from the 50mV setting to the 150mV setting has a lot of variation, which is why we do not recommend using resistors between 30 kOhm and 55 kOhm.

    Your problem is likely caused by the variation in the transition between the low and high current setting. Using a probe or tweezers could inject noise and transition the hold current to the high setting.

    The only recommendation for Rsense, Rpeak, and Rhold is that the voltage across the sense resistor is more than 30 mV. This effectively limits Rpeak to be less than 2 MOhm and Rhold to be less than 333 kOhm. Otherwise, there are no restrictions.

    Your values of 0.39 Ohm for Rsense and 77.7 kOhm for Rhold should solve the issue.

    Best,
    Grant