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SM72295: SM72295

Pawan Gupta
Prodigy 20 points
Part Number: SM72295

I am facing a problem while using this full bridge driver. The DC bus is 24VDC. When we switch on the DC power the output voltage is generated in a full bridge configuration that is stepped up using a power transformer connected to the two junction points of two half bridges. 

The circuit generates the voltage but within a second the driver burns giving it smoke. 

Is it because HSA pin-28 directly connected to top side MOSFET source. Which will be connected to 24v when the MOSFET is switched on ? Please suggest alternate solution.

Thanks

  • 0
    TI__Genius 9401 points

    Hello,

    Thank you for your question. Both HSA and HSB pins are rated for up to 100V, so 24V should on these pins should not be a problem.

    First thing to check is the power dissipation of the device to make sure the recommended maximum junction temperature (125C) that the device can handle is not being exceeded.  The datasheet section "Power Dissipation Considerations" has details about how to estimate the power dissipation based on your switching frequency, output load capacitance and VDD voltage. Once you calculate the power that the device needs to dissipate, you can use that power (P) to estimate the junction temperature (Tj) based on your maximum ambient temperature (Ta) and the junction to ambient thermal resistance for this device (RθJA = 60 W/°C), using:

    Tj = (P * RθJA) + Ta

    The calculated Tj should not exceed the 125°C recommended max junction temperature for this device. 

    Best regards,

    Leslie