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LTC4415 in continuous diode OR mode

Hello,

I am designing a LiFePO4 charger/battery backup UPS with the LTC4415 as the diode OR. I would like to know is it safe to operate the device with both diodes enabled continuously as a diode OR, with Vin1 at +5VDC and Vin2 at +3.65VDC ? Will the device function as a diode OR with both diodes continuously and indefinitely enabled ? 

Thank you, Andrew

  • Hi Andrew,
    It should be fine. From page 9 in the datasheet:

    "When the output of either diode is driven higher than its
    input by an alternate supply, conduction through that diode
    is suspended to prevent reverse conduction from OUT1/
    OUT2 to IN1/IN2. This function allows implementation of
    a power supply OR function by simply tying the outputs
    OUT1 and OUT2 together."

    In the sim below, the STAT pins show when the ideal diodes are disabled to prevent backfeeding into the smaller supply.


    -Aaron

  • True !  I have verified this on the 1819A Eval board using 5.0 & 3.5 VDC supplies with the Enable control mode jumper set to {both} mode with a 1A continuous load for over 1 hour with no issues.  Excellent !