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BQ25619EVM:Difference between CHG_CONFIG and BATFET_DIS

Part Number: BQ25619EVM
Other Parts Discussed in Thread: BQ25619

Hi TI team,

I have a doubt about the difference between CHG_CONFIG and BATFET_DIS.

If set CHG_CONFIG=0, it will stop battery charge immediately by turn off BATFET. 

If set BATFET_DIS=1, it also stop battery charge after the time BATFET_DLY by turn off BATFET.

So, both of these methods are the same to turn off BATFET, right?

BR

Eleven

  • Hi Chen:

    BATFET_DIS can disable both charge and discharge of battery. But CHG_CONFIG can disable charge only.

    Regards,

    Hong

  • Hi Hong,

    Thanks very much!

    In BQ25619 datasheet, it shows the BATFET will be latched-off after BATFET OCP trigger.

    I test the ocp function in the BQ25619 EVM, and the batfet_dis bit could be set to 0 after batfet_dis=1 due to BATFET OCP trigger. 

    So it seems the BATFET is not latched-off.

    Could you help how to understand the BATFET latch-off after BATFET OCP trigger?

    8.3.9.2.2
    PMID Over-Current Protection
    The BQ25619/618 closely monitors the battery discharge current through BATFET (Q4) to ensure safe boost mode operation. During over-current condition when Boost input current exceeds ISYS_OCP_Q4, the device latches off in 100 µs. When over-current condition is detected, the fault register bit BOOST_FAULT is set high to indicate fault in boost operation. An INT is asserted to the host.

    BR

    Eleven

  • Hi Eleven:

    Latch-off means BATFET is off. But it can be turned back on. Below is from datasheet:

    If only the battery is present and the voltage is above depletion threshold (VBAT_DPLZ), the BATFET turns on and

    connects the battery to the system. The REGN stays off to minimize the quiescent current. The low RDSON of

    BATFET and the low quiescent current on BAT minimize the conduction loss and maximize the battery run time.

    The device always monitors the discharge current through BATFET. When the system is overloaded or shorted

    (IBAT > ISYS_OCP_Q4), the device turns off BATFET immediately.

    With I2C, when the BATFET turns off due to over-current, the device sets the BATFET_DIS bit to indicate the

    BATFET is disabled until the input source plugs in again or one of the methods described in the BATFET Enable

    (Exit Ship Mode) section is applied to re-enable BATFET.

    When the BATFET is disabled (in ship mode) as indicated by setting BATFET_DIS, one of the following events

    can enable the BATFET to restore system power:

    1. Plug in adapter

    2. Clear BATFET_DIS bit

    3. Set REG_RST bit to reset all registers including BATFET_DIS bit to default (0)

    4. A logic high to low transition on QON pin with tSHIPMODE deglitch time to enable BATFET to exit ship mode.

    EN_HIZ bit is set to 1 (regardless of adapter present or not). Host has to set EN_HIZ bit to 0 before boost

    mode enable. Once adapter plugs in, EN_HIZ will be cleared.