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Original question:

[FAQ] BQ25750 and BQ25751: How To Connect The BQ25750 or BQ25751 IC If The Power Path Is Not Needed

BQ25750: Operation without BATFETs, Auto-Reverse Mode

Lukas Simon
Prodigy 120 points

Part Number: BQ25750

Question 1: BATFET-less Operation & Auto-Reverse Mode

I would like to use the BQ25750 without utilizing the BATFETs. (See attached picture) My intended application flow is as follows:

  1. Charge the battery normally via the buck-boost converter.

  2. If the input source disappears, I want to use the Auto-Reverse-Mode to generate 24V on the system rail from the battery.

  • Is this specific configuration (no BATFETs + Auto-Reverse Mode to 24V + ACFETS to prevent reverse current into input source) fully supported and possible?

  • Regarding the hardware setup, is the BATSRC pin correctly connected in my schematic for this use case? (Please see the attached picture for reference).

Screenshot 2026-03-25 152942.png

Question 2: Priority Between Reverse Mode and Forward Charging

Assuming the device is successfully operating in reverse mode (because Auto-Reverse Mode was enabled and the input was removed), I want to understand the transition priority when the input returns.

If the device is actively delivering power in reverse mode, and a valid input voltage is reapplied while the Charge Enable (CE) pin is asserted:

  • Does the BQ25750 automatically prioritize forward charging?

  • Will it seamlessly stop reverse mode and immediately start charging the battery, or is host intervention required to manage this transition?

Thank you in advance

  • 0
    TI__Mastermind 40036 points

    Hello Lukas,

    Lukas Simon said:
    Is this specific configuration (no BATFETs + Auto-Reverse Mode to 24V + ACFETS to prevent reverse current into input source) fully supported and possible?

    Yes, this is possible and supported

    Lukas Simon said:
    Regarding the hardware setup, is the BATSRC pin correctly connected in my schematic for this use case? (Please see the attached picture for reference).

    Yes, this is correct.

    Lukas Simon said:
    Does the BQ25750 automatically prioritize forward charging?

    Yes.

    Lukas Simon said:
    Will it seamlessly stop reverse mode and immediately start charging the battery, or is host intervention required to manage this transition?

    Auto reverse mode will seamlessly stop reverse mode and start charging the battery when the VAC voltage goes into the "power good" range.

    We have an FAQ on the power path switchover and reverse mode that may help.

    Best Regards,
    Ethan Galloway