S-8211DAD-M5T1X Datasheet, PDF (18/38 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC FOR 1-CELL PACK
S-8211D Series
Rev.6.5_02
5. Abnormal charge current detection
During charging a battery which is in the normal status, if the VM pin voltage becomes lower than the charger
detection voltage (VCHA) and this status is held longer than the overcharge detection delay time (tCU), the S-8211D
Series turns off the charge-control FET to stop charging. This is abnormal charge current detection.
This function works in the case that the DO pin voltage is in "H", and the VM pin voltage becomes lower than the
charger detection voltage (VCHA). Thus if the abnormal charge current flows in the battery in the overdischarge status,
the S-8211D Series turns off the charge-control FET to stop charging; the DO pin voltage goes in "H" so that the
battery voltage becomes higher than the overdischarge detection voltage (VDL), and after the overcharge detection
delay time (tcu).
The status of abnormal charge current detection is released by the lower potential difference between the VM pin and
the VSS pin than the charger detection voltage (VCHA).
6. 0 V battery charge function "available"
This function is used to recharge a connected battery whose voltage is 0 V due to self-discharge. When the 0 V
battery charge starting charger voltage (V0CHA) or a higher voltage is applied between the EB+ pin and EB− pin by
connecting a charger, the charging control FET gate is fixed to the VDD pin voltage.
When the voltage between the gate and source of the charging control FET becomes equal to or higher than the turn-
on voltage due to the charger voltage, the charging control FET is turned on to start charging. At this time, the
discharging control FET is off and the charging current flows through the internal parasitic diode in the discharging
control FET. When the battery voltage becomes equal to or higher than overdischarge release voltage (VDU), the
S-8211D Series enters the normal status.
Caution Some battery providers do not recommend charging for a completely self-discharged battery. Please
ask the battery provider to determine whether to enable or inhibit the 0 V battery charge function.
7. 0 V battery charge function "unavailable"
This function inhibits recharging when a battery that is internally short-circuited (0 V battery) is connected. When the
battery voltage is the 0 V battery charge inhibition battery voltage (V0INH) or lower, the charging control FET gate is
fixed to the EB− pin voltage to inhibit charging. When the battery voltage is the 0 V battery charge inhibition battery
voltage (V0INH) or higher, charging can be performed.
Caution Some battery providers do not recommend charging for a completely self-discharged battery. Please
ask the battery provider to determine whether to enable or inhibit the 0 V battery charge function.
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