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TPS84610: Effects of applying output voltage while device is disabled

Other Parts Discussed in Thread: TPS84610

Hi Team,

I am using TPS84610 for an application. I need to evaluate the performance of my load without using the DC/DC module. Can I safely connect an external DC source on my output of TPS84610 while holding the INH pin low so that I disable the chip.

I am assuming I will observe a voltage( = output voltage - body diode drop of high side FET) of the chip.

My question is, will this have any adverse effects on the chip given that there are logic and control blocks connected to the input pin.

Thanks!

  • As you described, applying a voltage to the output will back feed a voltage to the input through the body diode of the high side FET. If there is any other circuitry or low impedance path connected to the input, the amount of current draw could damage the body diode of the high side FET.

  • Hi,

    Thanks for your response. Just 2 more follow up questions -

    1. Is there a known current value after which the body diode will be damaged?

    2. Aside from overcurrent through the diode, will there be adverse effects due to the presence of voltage on the input pin of the chip specifically in the control and logic blocks within the chip?

    Thanks!

  • 1. I don't know a value, but I would avoid any Vin short to ground and I would recommend ramping Vout as opposed to abruptly applying Vout to avoid large inrush current.
    2. As long as you keep the INH pin low, this should be OK