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DRV8262: DRV8262 Damaged in testing

Shubham S
Prodigy 50 points
Part Number: DRV8262


Tool/software:

Hi,

While testing motor driver DRV8262 we observed that our 5V supply got shorted and damaged DRV8262. We suspect that an excess current was drawn by it to maintain motor position. The controller supplying PWM, VREF and other related signals also got damaged, despite having ESD Diodes.

Can you please suggest a suitable protection circuit in addition to schematic shared below. 

5V is being generated by AZ1084CD and 3V3 by LD29150DTR33R. 

regards,

  • 0
    TI__Mastermind 46025 points

    Hi,

    Thank you for your question. Our expert will feedback to you in next week.

  • 0 in reply to Shinya Morita
    TI__Mastermind 47595 points

    Hi Shubam,

    Shubham S said:
    5V is being generated by AZ1084CD and 3V3 by LD29150DTR33R. 

    Is the AZ1084CD input from the 12 V supply? Both regulator circuits you shared seem to be showing U1 for 3.3 V only. The VCC pin does not load the 5 V more than 10 mA - see below plots from page-12 of the DRV8262 datasheet. The regulator you mentioned can supply a lot higher current. However, I noticed the absolute maximum input voltage of that regulator is only 13.2 V. As long as you can guarantee the input won't go higher than this it should be okay else you may have to use a higher abs max rated LDO.

    Looks like VM in your application is 48 V, correct? What is the load, a BDC motor? What is max current? When exactly the VCC 5 V regulator would fail please describe the driver / motor operation that caused failure? Thank you. 

    Regards, Murugavel  

  • 0 in reply to Murugavel4637
    Prodigy 50 points

    Hello Murugavel,

    The 12V i/p is given via external automotive DC-DC Converter, its output is regulated we have tested it. The load is BDC Motor 250W, 13A, 24V. We are controlling the input to motor by PWM, only 10% duty is kept so  it is 10% of 48V.

    When the damage occurred  PWM, DIR and nSLEEP that were connected to MCU also damaged it. So basically, almost every Component on 3V3 &5V line got damaged.

    Can putting a series Schottky diode with low voltage drop be useful to protect other component from DRV damage?

    regards,

  • 0 in reply to Shubham S
    TI__Mastermind 47595 points

    Hi Shubam,

    Thanks for further details. 

    Generally these operating conditions should not cause any such failures to happen. I think there may be something else in your system that may be causing this issue. Without understanding the root cause a trial and error approach such as series Schottky diode may not be the right solution. Perhaps the DRV8262 was damaged first? Does the DVDD drive anything externally? I noticed it is connected to J4. 

    In our DRV8262EVM the driver device is directly driven by a 3.3 V MSP430 MCU. The VCC is powered by 3.3 V. We have tested the EVM up to its maximum operating voltage 60 V with no issues of MCU or 3.3 V regulator damage. You can download the schematic from the EVM webpage, https://www.ti.com/tool/DRV8262VEVM. 

    This device has been used in several applications with similar 3.3 V or 5 V MCU interface with no such issues you were facing. We need to understand the root cause. Can you try this application with 24 V and see if there is no failures and slowly increase the VM from there? Thank you.

    Regards, Murugavel