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TPS7A7001 reverse current

mwikman
Prodigy 70 points
Other Parts Discussed in Thread: TPS7A7001

Hi,

We have this application where we are planning to use TPS7A7001 linear voltage regulator. In this application the OUTPUT voltage could be at 2.5V for ~30 seconds even after the input voltage has been removed.  The maximum current  the 2.5V net can provide is about 230mA.

Is it required to a diode between the INPUT and the OUTPUT pins of TPS7A7001 to protect the device from this reverse current or is it okay to leave it as is? The EN pin is controlled externally from a power detection circuit.

  • 0
    TI__Guru 55940 points
    Hi Marten,

    TPS7A7001 does not have reverse current protection. Placing a diode will protect the device against reverse current. Another option is to add a discharge circuit to the output. A FET could be placed to discharge the output rail.

    Very Respectfully,
    Ryan
  • 0 in reply to Ryan Eslinger
    Prodigy 70 points
    Hi Ryan,

    Thank your for your answer. In this application we would prefer not to have any extra discharge circuit on the output as it is system requirement that the micro controller can run on the output capacitance for a limited time after power has been removed.

    What happens if the EN-pin is low and Vin=4V and Vout=2.5V. Will current be able to flow from the output through TPS7A7001 or will the current through TPS7A7001 be close to 0mA?
  • 0 in reply to mwikman
    TI__Guru 55940 points
    Hi Marten,

    As long as Vin is greater than Vout, there will be no reverse current. I apologize if I misunderstood, I thought you meant that Vin would be below Vout for 30s.

    If Vin =4V, Vout = 2.5V, and EN is low, the only current should be the the Ignd (shutdown) which per the Electrical Characteristics table will be less than 5uA.

    Very Respectfully,
    Ryan