AP9221

Document number: DS42177 Rev. 3 - 2

8 of 16

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May 2021

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AP9221

Application Information

Operation Mode

1. Normal Status

The AP9221 monitors the battery voltage and voltage difference between the VDD pin and VSS pin to control battery charging and discharging.

The AP9221 will turn on discharging and charging MOSFET when the battery voltage is between the overdischarge detection voltage (VDL) and

overcharge detection voltage (VCU), and the VM pin voltage is between the charge overcurrent detection voltage (VCOC) and discharge overcurrent

detection voltage (VDOC). In these conditions, the battery can charge and discharge freely. The RVMD also does not connect to the VDD pin. In this

status, the RVMS does not connect to VSS pin.

2. Overcharge Status

If the battery voltage is more than VCU during charging status for the overcharge detection delay time (tCU) or longer, the AP9221 turns off the

charging MOSFET to stop charging. RVMD and RVMS are not connected in overcharge status.

When VM pin voltage is lower than VDOC and battery voltage falls below VCL, the AP9221 will release from overcharge status.

When VM pin voltage is equal or more than VDOC and battery voltage falls below VCU, the AP9221 will release from overcharge status.

3. Overdischarge Status

If the battery voltage is less than VDL during discharging status for the overdischarge detection delay time (tDL) or longer, the AP9221 turns off the

discharging MOSFET to stop discharging. In overdischarge status, the RVMD is connected to the VDD, and VM pin voltage is pulled up to VDD by

RVMD

(but RVMS is not connected). For the power-down mode version, the AP9221 recovers into normal status from overdischarge status only by

charging the battery through the charger.

When VM pin voltage to VSS pin voltage is less than the typical -0.7V and the battery voltage rises over VDL, the AP9221 will release from

overdischarge status. If VM pin voltage to VSS pin voltage is higher than the typical -0.7V, the AP9221 will release from overdischarge status until

the battery voltage rises over VDU.

For auto-wake-up version AP9221SA, the device recovers into normal status from overdischarge status if either of these two conditions are

satisfied:

If a charger is connected:

the AP9221SA overdischarge status is released in the same way as described above in “AP9221S Overdischarge Status”

section.

If no charger is connected:

1) the battery voltage reaches the overdischarge release voltage (VDU) or higher;

2) it maintains continuous time more than overdischarge release delay time tDLR.

4. Discharge Overcurrent and Short Current Status

If the battery is in discharge overcurrent status, the voltage of the VM pin to VSS pin is equal or more than VDOC to VSHORT, and detection lasts for

the discharge overcurrent detection delay time (tDOC) or longer, the AP9221 turns off the discharging MOSFET to stop discharging.

If the battery is in short current status, the voltage of the VM pin to VSS pin is equal to or more than VSHORT, and the detection lasts for the short

current detection delay time or longer, the AP9221 turns off the discharge MOSFET to stop discharging.

In discharge overcurrent or short current status, RVMS is connected to VSS

, but RVMD is not connected. The voltage of VM pin is almost equal to

VDD as long as the load is connected. When the load is disconnected, the voltage of VM pin will become almost equal to VSS (due to RVMS being

connected) and then the AP9221 will release from discharge overcurrent or short current status.

5. Charge Overcurrent Status

If the battery is in charge current status, the voltage of the VM pin to VSS pin is equal to or less than VCOC, and the detection continues for the

charge overcurrent detection delay time (tCOC) or longer, the AP9221 turns off the charging MOSFET to stop charging.