S-8205AAA-TCT1U Datasheet, PDF (16/33 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC FOR 4-SERIES OR 5-SERIES CELL PACK
S-8205A/B Series
Rev.1.9_00
 Operation
Remark Refer to " Connection Examples of Battery Protection IC".
1. Normal Status
In the S-8205A/B Series, both of CO pin and DO pin get the V_DD level when the voltage of each of the batteries is in
the range of overdischarge detection voltage (V_DLn) to overcharge detection voltage (V_CUn), and due to the discharge
current, the VINI pin's voltage is in the range of charge overcurrent detection voltage (V_CIOV) to discharge overcurrent
detection voltage (V_DIOV). This is the normal status. At this time, the charge and discharge FETs are on.
2. Overcharge Status
In the S-8205A/B Series, the voltage of one of the batteries increases to the level of more than V_CUn, the CO pin is set
in high impedance. This is the overcharge status. The CO pin is pulled down to EB− by an external resistor so that
the charge FET is turned off and it stops charging.
The overcharge status is released if either condition mentioned below is satisfied;
(1) In case that the CO pin voltage is 1 / 50 × V_DS or less, and the voltage of each of the batteries which are V_CUn
or more is in the level of overcharge release voltage (V_CLn) or less.
(2) In case that the CO pin voltage is 1 / 50 × V_DS or more, and the voltage of each of the batteries is in the level
of V_CUn or less.
3. Overdischarge Status
In the S-8205A/B Series, when the voltage of one of the batteries decreases to the level of V_DLn or less, the DO pin
voltage gets the V_SS level. This is the overdischarge status. The discharge FET is turned off and it stops discharging.
The overdischarge status is released if either condition mentioned below is satisfied;
(1) In case that the VM pin voltage is in the level of less than V_SS, and the voltage of each of the batteries is in the
level of V_DLn or more.
(2) In case that the VM pin voltage is V_DS / 5 (typ.) or less and the VM pin voltage is in the level of more than V_SS,
and the voltage of each of the batteries which are V_DLn or less is in the level of overdischarge release voltage
(V_DUn) or more.
3. 1 With power-down function
In the S-8205A/B Series, when it reaches the overdischarge status, the VM pin is pulled up to the V_DD level by a
resistor between VM pin and VDD pin (R_VMD). If the VM pin voltage and the CO pin voltage increase to the level of
V_DS / 5 (typ.) or more, respectively, the power-down function starts to operate and almost every circuit in the
S-8205A/B Series stops working.
The power-down function is released if either condition mentioned below is satisfied;
(1) The VM pin voltage gets V_DS / 5 (typ.) or less.
(2) The CO pin voltage gets V_DS / 5 (typ.) or less.
4. Discharge Overcurrent Status
The discharging current increases to a certain value or more. As a result, if the status in which the VINI pin voltage
increases to the level of V_DIOV or more, the DO pin gets the V_SS level. This is the discharge overcurrent status. The
discharge control FET is turned off and it stops discharging. In the status of discharge overcurrent, the CO pin is set
in high impedance. The VM pin is pulled down to the V_SS level by a resistor between VM pin and VSS pin (R_VMS).
S-8205A/B Series has two levels for discharge overcurrent detection (V_DIOV, V_SHORT).
The S-8205A/B Series' actions against load short circuit detection voltage (V_SHORT) are as well in V_DIOV.
The discharge overcurrent status is released if the following condition is satisfied.
(1) The VM pin voltage gets V_DS / 10 (typ.) or less.
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