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DRV8801 Energy/peak pulse power

anuja karadkhedkar
Prodigy 140 points
Other Parts Discussed in Thread: DRV8801

Hello,

What is the peak  pulse power the DRV8801 can handle ?

Is there any peak pulse power Vs time graph available ?

I am dissipating over 4W of power for 5ms and would like to calculate if DRV8801 can handle this.

Thanks

Anuja

  • 0
    TI__Mastermind 26065 points

    Hi Anuja

    In normal running condition, the MAX current of DRV8801 will be limited by the regulation setting. If the regulation is not used, for example the SENSE pin is connected to GND, the current should be limited by OCP(min 3A) with the Tdeg and Tocp control.

    The MAX power can happen to the device is Imax^2*Rdson(0.74+0.52). Let's take the Imax as 3A, the result is >4W. This could happen only when the thermal PAD is good enough to keep the device away from thermal shut down.

    I don't think there will be any issue with only 5ms duration. Of course the PowerPAD of the device is recommended to connect to large copper area of GND net.

    Best regards,

  • 0 in reply to Wilson Zuo
    Prodigy 140 points

    Wilson,

     Imax^2*Rdson(0.74+0.52). is true only for Overcurrent deglitch time which is 3us.

    If I calculate the net energy : I.ocp^2 * Rdson(0.74+0.52) * t.DEG  , it is only 4.185 * 10^-5 Joules which is lesser than the minimum required for me (2.1A current for 5ms ).

     

    would be great if you could send me any graphs of pulse power etc.

     

     

  • 0 in reply to anuja karadkhedkar
    TI__Mastermind 20985 points

    Anuja, the integrated power over time (energy) will cause the device to heat, and the limit is dependent on your particular board's ability to dissipate heat. For example, the size of ground planes and the use of 2oz copper are factors.

    As for peak current limits, what Wilson said looks true to me (it's based on sense or OCP).

    Best regards,
    RE