S-8241 Datasheet, PDF (22/38 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 1-CELL PACK

BATTERY PROTECTION IC FOR 1-CELL PACK
S-8241 Series
Rev.7.6_00
2. <For products with power-down function>
After having detected an overcurrent (overcurrent 1, overcurrent 2, short-circuiting), the state is
held for the overdischarge detection delay time or longer without releasing the load, the condition
changes to the power-down condition when the battery voltage drops below the overdischarge
detection voltage. If the battery voltage drops below the overdischarge detection voltage due to
overcurrent, the discharging control FET is turned off when the overcurrent is detected. If the
battery voltage recovers slowly and if the battery voltage after the overdischarge detection delay
time is equal to or lower than the overdischarge detection voltage, the S-8241 changes to the
power-down condition.
<For products without power-down function>
After having detected an overcurrent (overcurrent 1, overcurrent 2, short-circuiting), the state is
held for the overdischarge detection delay time or longer without releasing the load, the condition
changes to the overdischarge condition when the battery voltage drops below the overdischarge
detection voltage. If the battery voltage drops below the overdischarge detection voltage due to
overcurrent, the discharging control FET is turned off when the overcurrent is detected. If the
battery voltage recovers slowly and if the battery voltage after the overdischarge detection delay
time is equal to or lower than the overdischarge detection voltage, the S-8241 changes to the
overdischarge condition.
8. 0 V Battery Charging Function
This function enables the charging of a connected battery whose voltage is 0 V by self-discharge. When a charger
having 0 V battery start charging charger voltage (V_0CHA) or higher is connected between EB+ and EB- pins, the
charging control FET gate is fixed to V_DD potential. When the voltage between the gate and the source of the charging
control FET becomes equal to or higher than the turn-on voltage by 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. If the battery voltage becomes equal to or higher than the
overdischarge release voltage (V_DU), the normal condition returns.
Caution 1. Some battery providers do not recommend charging of completely discharged batteries. Please
refer to battery providers before the selection of 0 V battery charging function.
2. The 0 V battery charging function has higher priority than the abnormal charge current detection
function. Consequently, a product with the 0 V battery charging function charges a battery and
abnormal charge current cannot be detected during the battery voltage is low (at most 1.8 V or
lower).
3. When a battery is connected to the IC for the first time, the IC may not enter the normal condition
in which discharging is possible. In this case, set the VM pin voltage equal to the V_SS voltage
(short the VM and VSS pins or connect a charger) to enter the normal condition.
9. 0 V Battery Charge Inhibiting Function
This function forbids the charging of a connected battery which is short-circuited internally (0 V battery). When the
battery voltage becomes 0.9 V (typ.) or lower, the charging control FET gate is fixed to EB- potential to forbid charging.
Charging can be performed, when the battery voltage is the 0 V battery charge inhibiting voltage (V_0INH) or higher.
Caution 1. Some battery providers do not recommend charging of completely discharged batteries. Please
refer to battery providers before the selection of 0 V battery charging function.
2. When a battery is connected to the IC for the first time, the IC may not enter the normal condition
in which discharging is possible. In this case, set the VM pin voltage equal to the V_SS voltage
(short the VM and VSS pins or connect a charger) to enter the normal condition.
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Seiko Instruments Inc.