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BQ24702: Charger ICs for devices that use more current (in burst) than the adapter can provide

Part Number: BQ24702
Other Parts Discussed in Thread: BQ25703A, BQ24780S

All the parts I have been finding (such as BQ24702) seem to require that the adapter can supply more than the peak system load.

I need something for which that is true over long periods of time on average, but not at all times. For example, a system that periodically turns on for 1 second and uses 10 A when it's on and ~0A when it's off the rest of the time, while the charger supplies 500 mA constantly.

The ideal behavior would be that in the off state the battery is getting charged at 500 mA, whereas when the system is on and charging, the charger provides 0.5A and the battery provides 9.5A.

Any suggestions of parts (preferably multi-cell) or literature to look into will be greatly appreciated. Thank you!

  • Hi Gatt,

    TI actually has many chargers which allow the adapter and the battery to supply power to the system at the same time. We call this supplement mode (for NVDC topology chargers, such as the BQ25703A) or turbo-boost mode (for hybrid topology chargers, such as the BQ24780S).

    During normal operation, the adapter will power the system while also charging the battery. However, when the system temporarily draws more power than the adapter can provide, the battery will discharge and "supplement" the adapter in order to keep the system running without letting the adapter crash.

    These links may be helpful to you if you want to learn more about how these features work:
    e2e.ti.com/.../understanding-battery-charger-features-and-charging-topologies
    www.ti.com/.../slyt546.pdf

    Best regards,
    Angelo