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DRV110 accuracy

Hello,

Our customer have a question about the accuracy of IPEAK, IHOLD, tKEEP and fPWM.

It is mentioned the accuracy of IPEAK and IHOLD on the datasheet. 

Is it applicable when the customer  use the RPEAK and RHOLD more than 33.33kohm?

Could you tell me the variation of the tKEEP and fPWM due to the process variation?

Of course, I know it is not guarantee.

Best Regards,

Naoki Aoyama

  • Hi Aoyama-san,

    Our experts have been notified and should reply soon.
  • Aoyama-san,

    The accuracy of IPEAK and IHOLD relates to the offset of the internal comparator. As a general rule, currents should be within +/-30 mA of the programmed current for an RSENSE resistor of 1 Ohm. This should be the case for all values of RPEAK and RHOLD.

    The variation of tKeep is +/-30% of the calculated value.

    The PWM frequency will be within +/-35% according to the GATE DRIVER section of the datasheet.

  • Hello James-san,

    Thank you for your reply and detail information.
    I will feedback the customer the information.

    Thanks,
    Naoki Aoyama
  • Hello James-san,

    I'm sorry but the customer do not satisfy the accuracy of tKEEP as +/- 30%.

    If the accuracy of  tKEEP as so, the accuracy of the customer's system may be over +/- 50%, 

    because it is added the accuracy of the external capacitance.

    Could you tell me how about the combination the accuracy of tKEEP?

    1uA current source, 100mV reference voltage, offset of the comparator, temperature, margin and so on.

    Best Regards,

    Naoki Aoyama

  • Aoyama-san,

    The +/-30% tolerance of tKEEP is determined from simulations done for the part over temperature. It's not entirely part-to-part variation. At room temperature, you should see nominal performance.

    Why does the customer require tighter accuracy for tKEEP? What are they building? The KEEP time only needs to be long enough to ensure actuation of the solenoid. Do they have certain timing requirements in their system that require a precise KEEP time?

    We don't have that accuracy information readily available, and we would need to run some simulations. Please send me a private message with the name of the customer, the end equipment the customer is building, the estimated volume, and production date. This will be helpful for me to get my group to prioritize this simulation.
  • Hello James-san,

    Thank you for your reply.
    I will send you the information of the customer by E-mail.
    Thanks,

    Naoki Aoyama