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DRV8837: About VM current at some mode

Tao_2199
Genius 5660 points
Part Number: DRV8837

Hello,

  

Regarding to VM current on DRV8837, my customer is asking some question.

 

(Question)

 

(1) When VCC<1.7 V (VCC undervoltage), the device enters a low-power state and

VM current(Ivm:=40uA(typ)）gets lower more.

My understanding is correct?

 

(2)When VCC doesn't supply and only VM supply , is there any impact on this device?

 

(3) When the condition(mode) is as following, how many milliampere will be VM consumption currents?

(All mode is on 100% duty cycle drive)

　･No_PWM 40～100uA_max

　･Reverse/Forward

　･Brake

　･Coast

 

Regards,

Tao 2199

  • 0
    TI__Genius 14485 points
    Hello Tao_2199,

    (1) Correct. When VCC is below the UVLO threshold (1.7 V), the current consumption will be low. I don't know how much current it will draw in UVLO, but it will likely be similar to the sleep current the device draws in sleep mode (I_VCCQ and I_VMQ).

    (2) The device will be in UVLO. In this state it will not be operational, but there will not be any damage either.

    (3) If there is a load, the current requirement of the load will be much higher than the current requirement of the IC. The IC by itself will draw currents specified by I_VM and I_VCC in the datasheet.
  • 0 in reply to James Lockridge19
    Genius 5660 points

    Hello James,

     

    Thank you for reply.

     

    About Question(3)

     

    ･When PWM current is 100uA(max), VM current will be total current which PWM current(100uA) plus VM operating supply current.

     

    My understanding is correct?

     

    Regards,

    Tao 2199

  • 0 in reply to Tao_2199
    TI__Genius 14485 points
    Tao_2199,

    Correct. The current into VM will be I_VM+I_LOAD.