s-8241abtmc-gbtt2g Seiko Instruments Inc., s-8241abtmc-gbtt2g Datasheet - Page 19

• Manufacturer Part Number: s-8241abtmc-gbtt2g
• Description: Battery Protection Ic For 1-cell Pack
• Manufacturer: Seiko Instruments Inc.

Rev.7.9
3. Overcharge Condition
When the battery voltage becomes higher than the overcharge detection voltage (V
condition and the state continues for the overcharge detection delay time (t
control FET off to stop charging. This condition is called the overcharge condition.
The overcharge condition is released in the following two cases ((1) and (2)) depending on the products with and without
overcharge hysteresis:
Products with overcharge hysteresis (overcharge detection voltage (V
Products without overcharge hysteresis (Overcharge detection voltage (V
(1) When the battery voltage drops below the overcharge release voltage (V
(2) When a load is connected and discharging starts, the S-8241 turns the charging control FET on and returns to the
(1) When the battery voltage drops below the overcharge release voltage (V
(2) When a load is connected and discharging starts, the S-8241 turns the charging control FET on and returns to the
normal condition. The release mechanism is as follows: the discharging current flows through an internal parasitic
diode of the charging FET immediately after a load is connected and discharging starts, and the VM pin voltage
increases about 0.7 V (V
(being higher than the overcurrent 1 detection voltage) and releases the overcharge condition. Consequently, in the
case that the battery voltage is equal to or lower than the overcharge detection voltage (V
normal condition immediately, but in the case the battery voltage is higher than the overcharge detection voltage
(V
voltage (V
1 detection voltage when a load is connected and discharging starts, the IC does not return to the normal condition.
Remark If the battery is charged to a voltage higher than the overcharge detection voltage (V
FET on and returns to the normal condition.
Remark If the battery is charged to a voltage higher than the overcharge detection voltage (V
FET on and returns to the normal condition.
normal condition. The release mechanism is explained as follows : the discharging current flows through an internal
parasitic diode of the charging FET immediately after a load is connected and discharging starts, and the VM pin
voltage increases about 0.7 V (V
(being higher than the overcurrent 1 detection voltage), the IC increases the overcharge detection voltage about 50
mV, and releases the overcharge condition. Consequently, when the battery voltage is equal to or lower than the
overcharge detection voltage (V
battery voltage is higher than the overcharge detection voltage (V
normal condition until the battery voltage drops below the overcharge detection voltage (V
is connected. If the VM pin voltage is equal to or lower than the overcurrent 1 detection voltage when a load is
connected and discharging starts, the S-8241 does not return to the normal condition.
_00
CU
), the IC does not return to the normal condition until the battery voltage drops below the overcharge detection
voltage does not drop below the overcharge detection voltage (V
causes an overcurrent, is connected, the overcurrent 1 and overcurrent 2 do not work until the battery
voltage drops below the overcharge detection voltage (V
internal impedance of several dozens of mΩ, and the battery voltage drops immediately after a heavy load
which causes an overcurrent is connected, the overcurrent 1 and overcurrent 2 work. Detection of load
short-circuiting works regardless of the battery voltage.
voltage does not drop below the overcharge detection voltage (V
which causes an overcurrent, is connected, the overcurrent 1 and overcurrent 2 do not work until the
battery voltage drops bellow the overcharge detection voltage (V
however, an internal impedance of several dozens of mΩ, and the battery voltage drops immediately after
a heavy load which causes an overcurrent is connected, the overcurrent 1 and overcurrent 2 work.
Detection of load short-circuiting works regardless of the battery voltage.
CU
) even if the load is connected. In addition if the VM pin voltage is equal to or lower than the overcurrent
f
voltage of the diode) from the VSS pin voltage momentarily. The IC detects this voltage
CU
f
voltage of the diode) from the VSS pin voltage momentarily. Detecting this voltage
) + 50 mV, the S-8241 immediately returns to the normal condition. But the
Seiko Instruments Inc.
BATTERY PROTECTION IC FOR 1-CELL PACK
CU
CU
) + 50 mV, the S-8241 does not return to the
CU
). Since an actual battery has, however, an
) > overcharge release voltage (V
CU
CU
) or longer, the S-8241 turns the charging
CL
CU
CL
) = Overcharge release voltage (V
), the S-8241 turns the charging control
CU
) + 50 mV. Since an actual battery has,
), the S-8241 turn the charging control
CU
) + 50 mV even when a heavy load,
) even when a heavy load, which
CU
) during charging under normal
CU
CU
) + 50 mV even if a load
), the IC returns to the
S-8241 Series
CU
CU
) and the battery
) and the battery
CL
))
CL
))
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