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TPS2121: TPS2121

Koos Pieterse
Prodigy 60 points
Part Number: TPS2121

I have a 5V input and a 3.7-4.2V input

Using the Highest Voltage Operation mode, the start-up is not consistent.

Using the 23.7K and 5K for the 5V on IN1 what will the recommended resistor values be for the 3.7-4.2V on IN2 be?

  • 0
    TI__Genius 13260 points

    Hello Koos,

    If you're using Highest Voltage Operation then there's no resistor dividers to set.  

    Usually increasing input/output capacitance helps significantly with the transition from one input to another, but it's a balancing act.

    If you're trying to use priority mode now with FSW - we do not have any specific recommendations for the resistor dividers for each input level; however, I would suggest looking at the E2E FAQ posted below to help with seamless switchover. Just ensure that PR1 < 1.06V when you want IN2 to take over.

    If you're noticing supply swinging (continuous switching from one input to the other) then adding input/output capacitance can also help, but adding hysteresis as noted in the FAQ linked below will also significantly help.

    [FAQ] TPS2121: How do I Achieve a Seamless Power Switchover using TI’s Power Mux Devices

    Regards,

    Kalin Burnisde