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DRV8245-Q1: Max continuous current limit

Jan Zwiegers
Prodigy 220 points
Part Number: DRV8245-Q1

With reference to the DRV8245 rated at 32A max, it seems this is only intended for short periods.

What would be the "safe" continuous max current for this device if thermal requirements are met?

I'm aiming for a design where the max current is 15A and around 8A to 12A continuous.

  • +1
    TI__Guru 55615 points

    Jan,

    Please see the calculator in the tool folder.

    https://www.ti.com/product/DRV8245-Q1

    Thermal will be dominated by I^2*R losses in the device, so a good first order approximation is: 12A * 12A * 0.032ohms (high-side + low-side Rdson) = 4.61W.  Assuming 30C/W for thera-ja and that is 138 degrees of temp rise.  You will be right at thermal trip point with 25C ambient.  

    8A is more reasonable.  This also is only conducted losses.  Switching losses add on top of this.  Calculator takes into account everything.

    Regards,

    Ryan