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Original question:

DRV10983Q1EVM: Driver did not start the motor properly after few days working

DRV10983Q1EVM: Driver did not start the motor properly after few days working

Jihun Park
Prodigy 90 points
Part Number: DRV10983Q1EVM

Hi TI support team.

As I asked before, I'm using DRV10983Q1.

I had some problem but figured out thanks to your advice.

Now I have another issue about the DRV10983Q1

Recently,  I changed two things.

First I selected regulator mode from Buck mode to Linear mode by using resister instead inductor. 

Second Increase the BEMF comparator Hysteresis by setting the BEMF comparator hysteresis bit to "1".

After these change, the probability of successful starting increased, but some of DRV10983Q1 does not work any more after some times power reset. It seems broken because there is no VERG voltage when I measured. I mean it's voltage level is "0". All outputs of DRV10983Q1  are zero (SW, RVEG, V1P8 and V3P3).

Is there anything I have to check, please let me know.

Regards,

Peter

  • 0
    TI__Mastermind 18900 points

    Hey Peter,

    I'm sorry to hear that the motor driver isn't starting up. If the VREG voltage is zero after providing power to VCC, then the part is most likely damaged. I assume your power supply isn't pulling current equal to the current limit which would indicate a short and some other damage to the device.

    Before we get there, I'd like confirm that you are using the EVM, removed L1, and placed a 39ohm 1/4W rated resistor in the R7 or R6 footproint. Any other resistor value will not work.

    If so, then can you please confirm what the markings on the top of the device? 

    After that, you could try to remove the resistor and replace the inductor to see if it works again. If the device does not work with the same inductor, we know the device is probably damaged. If it does work after replacing with the same inductor again then there might be something else that we need to debug.

    Best,

    -Cole

  • 0 in reply to Cole Macias
    Prodigy 90 points
    Hi Cole,
    Now I'm using my modified PCB not the EVM, but Driver IC parts is almost same with EVM. I removed L1 and replaced 39ohm 1/4W resistor as you suggested before.
    The marking of IC is DRV10983Q 78TG4 AT5Z.
    Removing the resistor and replacing the inductor does not make the damaged device working
    I'v been testing  two hundreds of  the modified PCB with motor for few month as you know. and my first problem was a capacitor problem, and second was a starting problem, and now driver ic damage problem.
    This is the most important problem than before. 
    For more information, I tested like below
    1. number of samples: 100EA
    2. test method: input power(24VDC) on -->  2 seconds after drive the motor to rotate --> let the motor rotate for 1 minutes --> turn off the input power(24VDC) (motor may rotate for a few seconds)
    3. number of test: 390 times
    4. number of damaged driver: 33EA.
    This problem had the manufacture work stop. We need to solve this problem asap.
    I hope you have a good solution to figure this out.

    Can BEMF_HYS (HIGH) bit affect this kind of problem?

    Best,

    Peter

  • 0 in reply to Jihun Park
    TI__Mastermind 18900 points

    Hey Peter,

    I'm sorry to hear this is causing a production stop. Unfortunately, the answer to this problem still is not obvious. I assume you already know about sleep mode and how the device will need some voltage (analog or PWM) on the Speed pin to get the device to exit sleep, so this it sounds like the devices are damaged. I see 2 parallel paths that should be pursued simultaneously.

    Long term:

    Please reach out to your local TI Representative and explain that you would like to return some failed parts (usually 2-5) for failure analysis. Cite this E2E post and explain the situation. At that point, you can work with your manager and the TI Represenative to see if replacement parts are needed or if the failure analysis can be expedited. However, this still is still a couple of weeks of communication, shipping, and analysis which makes it a long term process.

    Short term:

    For the short term, we need to try our best to debug because we haven't seen other customers report damage after a "power on and off" test like you've described. If possible, please provide your most recent EEPROM settings, a picture of the schematic, and the picture of that layout. Note, that I think the layout will be the most critical.

    In addition, I would recommend monitoring some waveforms for VCC Voltage, U Phase Voltage, Vreg, and FG. We need to see voltage on these pins and confirm there is no surging when we turn off the motor. As you probably know, when the motor is turned off, the energy stored in the phases (inductor) of the motor will try to resist the net change of current when VCC is turned off. If we know the phase voltage is higher than VCC then current could find a path to flow through the part (e.g. body diodes of the FETs or EOS or ESD diodes on any of the pins).

    If we find a point of potential failure, we can come up with some external protection (e.g. TVS) to help with the problem.   

    In addition, let me address some of the information you've made in your post:

    • The device marking is what we expect
    • The BEMF_HYS level won't cause this problem

    Best,

    -Cole