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Original question:

DRV8350: DRV835x sample schedule & Automotive version plan

DRV8350: Current consumption

Shunsuke Nagata
Genius 12290 points
Part Number: DRV8350

Hi,

I would like to know the total current consumption of DRV8350S with below condition

- VM = 12V, VDRAIN = 48V, and use 20 DRV8350S

At this time, I would like to know how much power is requires in VM power source.

Datasheet explains that IVM = 13mA ( MAX). Is this mean that VM power source requires 260mA ( = 20 units x 13mA)? 
Should user consider IVCP, IVGLS and IDVDD to the calculation?

Regards,
Nagata.

  • 0
    TI__Guru 61920 points

    Nagata-San,

    I would recommend ordering an EVM and checking this condition with your input style and motor. It is hard to accurately predict this information from my side.

    That condition where IVM max is 13mA is without any input, obviously this will be higher when input is present.

    Regards,

    -Adam

  • 0 in reply to Adam Sidelsky
    TI__Genius 12290 points

    Hi, Adam -san,

    Thank you for your supports. I just estimate the consumption at this moment.

    Could you please check IVCP and IVGLS.
    Are the IVCP and swiching of IVGLS supplied from external 1uF cap?

    I simply would like to know if IVM would not include IVCP and IVGLS.

    Regards,
    Nagata.

  • 0 in reply to Shunsuke Nagata
    TI__Guru 61920 points

    Nagata-San,

    Yes in the non-switching case the IVGLS/IVCP/IDVDD are included in the IVM value.

    In the switching case the VM current will increase due to the VCP switching current.

    Regards,

    -Adam

  • 0 in reply to Adam Sidelsky
    TI__Genius 12290 points

    Adam -san

    For your comment,

    —-

    In the switching case the VM current will increase due to the VCP switching current.

    —-

    How much current will increases in the switching case?

    Regards,

    Nagata.

  • 0 in reply to Shunsuke Nagata
    TI__Genius 12290 points

    Hi, Adam -san,

    Is the below Ivcp added to IVM ( = 13mA) in the switching case?
    e.g. if VM = 12V, Total VM current is 33mA( = 13mA + 20mA)

    Or is there charge time to charge external cap? With the condition such as VVCP=10V, external cap =  1uF and Ivcp = 20mA, charging time may 0.4ms ( =  1uF x 10V / 20mA). I believe the IVM may increase 20mA from 13mA for 0.4ms during switching if VM = 12V. Is my understanding correct?

    Regards,
    Nagata.

  • 0 in reply to Shunsuke Nagata
    TI__Guru 61920 points

    Nagata-San,

    The IVCP current will is the charge pump output, so this won't directly correlate with the VM input current. This being said your approximation sounds correct. You should verify this with hardware before you make any major design decisions using this information.

    Regards,

    -Adam