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Original question:

TPS22996H-Q1: Parallel Configuration

TPS22996H-Q1: Can I leave VIN powered while VBIAS is unpowered? (partial shutdown)

Niklas Gürtler
Prodigy 10 points
Part Number: TPS22996H-Q1

Tool/software:

On the TPS22996H-Q1, is it allowed to keep VIN1 and VIN2 permanently connected to a power source (LiPo battery, 2.8-4.2V) while VBIAS can be unpowered temporarily (floating, disabled via load switch)? ON1/2 will be pulled low via pull-down resistor in this case and the outputs should of course be off. I also would like to run both channels in parallel as in the linked thread.

The datasheet states that VINx should be <= VBIAS, but will the device be damaged if this is not the case? What is the leakage current into VINx in with VBIAS=open, can there be a leakage current to VOUTx?

Thanks!

  • 0
    TI__Mastermind 31491 points

    Hello Niklas,

    VBIAS is usually a steady power supply.

    What's the VBIAS and ON sequence? Is ON voltage comes after VBIAS voltage?

    Thanks 

    Amrit 

  • 0 in reply to Amrit Jit
    Prodigy 10 points

    Hi Amrit, thanks for the reply.

    VBIAS will be applied before the ON signal, i.e. ON will never be "high" without VBIAS supply.

    I'm using a BMS IC with an integrated load switch that turns off the main supply for my MCU, sensors etc when the battery is deep discharged. I also have a module with a high current consumption that is switched on/off using the TPS22996H-Q1, but since the BMS' integrated load switch has a too high on-resistance I need to connect the TPS22996H-Q1 VIN1/2 to the battery directly. I'd like to connect the TPS22996H-Q1 VBIAS supply to the BMS load switch output to reduce the standby current consumption if possible. The product will be in deep standby for long periods of time and only rarely enable the big consumer, so current consumption in standby adds up over time. When the BMS load switch is off, VBIAS will be off but also the MCU and therefore the ON signal will be off, only VIN will be connected to the battery.

    Best regards,
    Niklas

  • +1 in reply to Niklas Gürtler
    TI__Mastermind 31491 points

    Hello Niklas,

    Yes, it's fine to use under conditions described.

    VBIAS is required for the charge pump to turn ON the FET. During off condition VBIAS is not required for device to keep in OFF condition.

    Thanks

    Amrit