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DRV8889-Q1:DRV8889-Q1 no longer communicates via SPI

Masahiro Kita
Prodigy 20 points
Part Number: DRV8889-Q1

Tool/software:

Thank you for your help.

There have been three cases where circuits using the DRV8889-Q1 suddenly stopped working. The cause of these cases was a failure of the DRV8889-Q1. No output was obtained when commands were sent to the DRV8889 via SPI communication. Since it has been working fine up until now, we believe there is no problem with the communication process.

I am having trouble figuring out why the IC broke.

If there have been similar cases in the past, please let me know the cause and countermeasures.

(This text is written using Google Translate)

  • 0
    TI__Mastermind 44875 points

    Hi Kita-san,

    Thank you for your question.

    Masahiro Kita said:
    There have been three cases where circuits using the DRV8889-Q1 suddenly stopped working. The cause of these cases was a failure of the DRV8889-Q1. No output was obtained when commands were sent to the DRV8889 via SPI communication. Since it has been working fine up until now, we believe there is no problem with the communication process.

    It is possible for the IC to get damaged if the absolute maximum ratings were exceeded. See below from the datasheet. Even with normal operation, for example with VM = 24 V, it may be possible the stepper motor inductance may have induced momentary high voltage on the rail during switch over, external shorts make and break of the motor connections etc., 

    Please provide additional information such as VM voltage, IFS current VREF voltage, CONFIG1 to 6 registers settings, step rate etc. If there is any information of what led to the failure it would be useful for debug. As well as please share the schematic of the application. Thank you.

    Regards, Murugavel 

  • 0 in reply to Murugavel4637
    Prodigy 20 points

    Thank you for your quick reply.
    The parameters are listed below.

    VM: 13.5V
    IFS: 0.5A
    VREF: (=2.2*0.5*1.0 =1.1V)
    TRQ_DAC: 100%
    SLEW_RATE: 10V/µs
    TOFF:7us
    DECAY: 110b Dynamic attenuation
    SPI_DIR: 0b
    SPI_STEP: 0b
    MICROSTEP_MODE: 1000b = 1/64 step

    I have also attached the circuit diagram around the IC.
    It was created mostly with reference to the manual.

    Thank you in advance.

  • 0 in reply to Masahiro Kita
    TI__Mastermind 44875 points

    Hi Kita-san,

    Thank you for sharing the setup parameters and application details. Overall schematic looks fine. I do not see a bulk capacitor on VM (VCC) rail. You may need a capacitor value 47 to 100 uF electrolytic for bulk capacitor else inductive kickback from the stepper coils could induce higher than VM voltages on xOUTx pins and damage the device. Is VCC 13.5 V direct from a battery or is there a series diode for reverse voltage protection? Are D6 to D9 regular silicon junction diodes or ESD diodes? 

    What is the L and R of the stepper motor? Can we get a capture of one of the coils A or B, current waveform and xOUT1, 2 voltage waveform and VM rail waveform,  all 4-channels simultaneous? Thank you.

    Regards, Murugavel