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LMR14050: Reverse Leakage during Power OR-ing

Ryan.Bishop
Expert 3900 points
Part Number: LMR14050

Hello,

We want to use the LMR14050 in a power OR-ing application similar to the below diagram.

We are concerned about this scenario: At some points the input to the LMR14050 will be high impedance/floating. Also, when temperatures are high the reverse leakage of the schottky diodes can be high (1mA+). Do we need to be concerned about this 1mA+ leakage current flowing backwards to the input, which could raise the Vin/EN voltage above their thresholds.

Can you please let me know how the device will behavior in this scenario and if it could cause problems? Thank you!

Note: I forgot to draw in the feedback resistors. They will configure the output for 9V and I assume they will be in the 10's of kOhms.

Regards,
Ryan Bishop

  • 0
    TI__Genius 9550 points
    Hi,

    How about the input voltage range?
    The out put voltage is 9V instead of 12V(in your manual schematic, Vout is 12V), correct?
  • 0
    TI__Mastermind 33765 points
    Hi,

    If the bias voltage on output is higher than target output voltage, then chip VIN pin will see the bias voltage but works in standby mode without switching as output is biased higher than target output voltage.

    If bias voltage is lower than target output but higher than Vin UVLO, chip will works in low drop-out mode but inductor current is zero as VIN is almost same as output, if chip operation current higher than reverse leakage current, then chip may works in intermitten mode with Vin voltage oscillate near VIN UVLO.