S-8253A Datasheet, PDF (17/32 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 2-SERIAL OR 3-SERIAL-CELL PACK

Rev.3.7_00
BATTERY PROTECTION IC FOR 2-SERIAL OR 3-SERIAL-CELL PACK
S-8253A/B Series
5. Overcurrent Status
The S-8253A/B Series has three overcurrent detection levels (V_IOV1, V_IOV2, and V_IOV3) and three overcurrent detection
delay times (t_IOV1, t_IOV2, and t_IOV3) corresponding to each overcurrent detection level. When the discharging current
becomes higher than the specified value (the difference of the voltages of the VMP pin and VDD pin is greater than
V_IOV1) and the state continues for t_IOV1 or longer, the S-8253A/B Series enters the overcurrent status, in which the DOP
pin voltage becomes V_DD level to turn off the discharging FET to stop discharging, the COP pin becomes high
impedance and is pulled up to the EB+ pin voltage to turn off the charging FET to stop charging, and the VMP pin is
pulled up to the V_DD voltage by the internal resistor (R_VMD). Operation of overcurrent detection levels 2, 3 (V_IOV2, V_IOV3)
and overcurrent detection delay times 2, 3 (t_IOV2, t_IOV3) are the same as for V_IOV1 and t_IOV1.
The overcurrent status is released when the following condition holds.
(1) The VMP pin voltage is V_DD − V_IOV1 or higher because a charger is connected or the load is released.
Caution The impedance that enables automatic restoration varies depending on the battery voltage and set
value of overcurrent detection voltage 1.
6. 0 V Battery Charge Function
Regarding the charging of a self-discharged battery (0 V battery), the S-8253A/B Series has two functions from which
one should be selected.
(1) 0 V battery charging is allowed (0 V battery charging is available.)
When the charger voltage is higher than V_0CHA, the 0 V battery can be charged.
(2) 0 V battery charging is prohibited (0 V battery charging is unavailable.)
When one of the battery voltages is lower than V_0INH, the 0 V battery cannot be charged.
Caution When the VDD pin voltage is lower than the minimum value of V_DSOP, the operation of the S-8253A/B
Series is not guaranteed.
Seiko Instruments Inc.
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