S-8254AANFT-TB-G Datasheet, PDF (14/29 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 3-SERIAL- OR 4-SERIAL-CELL PACK

BATTERY PROTECTION IC FOR 3-SERIAL- OR 4-SERIAL-CELL PACK
S-8254A Series
Rev.5.0_01
„ Operation
Remark Refer to “„ Battery Protection IC Connection Example”.
1. Normal Status
When all of the battery voltages are in the range from V_DLn to V_CUn and the discharge current is lower than
the specified value (the VINI pin voltage is lower than V_IOV1 and V_IOV2, and the VMP pin voltage is higher
than V_IOV3), the charging and discharging FETs are turned on.
2. Overcharge Status
When any one of the battery voltages becomes higher than V_CUn and the state continues for t_CU or longer,
the COP pin becomes high impedance. The COP pin is pulled up to the EB+ pin voltage by an external
resistor, and the charging FET is turned off to stop charging. This is called the overcharge status. The
overcharge status is released when one of the following two conditions holds.
(1) All battery voltages become V_CLn or lower.
(2) All of the battery voltages are V_CUn or lower, and the VMP pin voltage is 39 / 40 × V_DD or lower (a
load is connected and discharging is started via the body diode of the charging FET).
3. Overdischarge Status
When any one of the battery voltages becomes lower than V_DLn and the state continues for t_DL or longer,
the DOP pin voltage becomes V_DD level, and the discharging FET is turned off to stop discharging. This
is called the overdischarging status. After discharging is stopped due to the overdischarge status, the S-
8254A Series enters the power-down status.
4. Power-down Status
When discharging has stopped due to the overdischarge status, the VMP pin is pulled down to the V_SS
level by the R_VMS resistor. When the VMP pin voltage is lower than V_DD / 2, the S-8254A Series enters
the power-down status. In the power-down status, almost all the circuits of the S-8254A Series stop and
the current consumption is I_PDN or lower. The conditions of each output pin are as follows.
(1) COP pin : High-Z
(2) DOP pin : V_DD
The power-down status is released when the following condition holds.
(1) The VMP pin voltage is V_DD / 2 or higher.
The following two conditions release the overdischarging status.
(1) In case the VMP pin voltage is V_DD / 2 or higher and the VMP pin voltage is lower than V_DD, the
overdischarging status is released when all battery voltages are V_DUn or higher.
(2) In case a charger is connected, the overdischarge hysteresis is released. And the overdischarging
status is released when all battery voltages are V_DLn or higher.
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Seiko Instruments Inc.