s-8211dat-i6t1g Seiko Instruments Inc., s-8211dat-i6t1g Datasheet - Page 16

• Manufacturer Part Number: s-8211dat-i6t1g
• Description: Battery Protection Ic For 1-cell Pack
• Manufacturer: Seiko Instruments Inc.

16
BATTERY PROTECTION IC FOR 1-CELL PACK
S-8211D Series
Operation
Remark Refer to the “ Battery Protection IC Connection Example”.
1. Normal Status
2. Overcharge Status
This IC monitors the voltage of the battery connected between the VDD pin and VSS pin and the voltage difference
between the VM pin and VSS pin to control charging and discharging. When the battery voltage is in the range from
overdischarge detection voltage (V
the discharge overcurrent detection voltage (V
This condition is called the normal status, and in this condition charging and discharging can be carried out freely.
The resistance (R
are not connected in the normal status.
Caution When the battery is connected for the first time, discharging may not be enabled. In this case,
When the battery voltage becomes higher than overcharge detection voltage (V
status and detection continues for the overcharge detection delay time (t
charging control FET off to stop charging. This condition is called the overcharge status.
The resistance (R
are not connected in the overcharge status.
The overcharge status is released in the following two cases ( (1) and (2) ).
(1) In the case that the VM pin voltage is higher than or equal to charger detection voltage (V
(2) In the case that the VM pin voltage is higher than or equal to the discharge overcurrent detection voltage (V
Caution 1. If the battery is charged to a voltage higher than overcharge detection voltage (V
When the discharge is started by connecting a load after the overcharge detection, the VM pin voltage rises more
than the voltage at VSS pin due to the V
flows through the parasitic diode in the charging control FET. If this VM pin voltage is higher than or equal to the
discharge overcurrent detection voltage (V
voltage is lower than or equal to the overcharge detection voltage (V
the discharge overcurrent detection voltage (V
battery voltage falls below the overcharge release voltage (V
S-8211D Series releases the overcharge status when the battery voltage falls below the overcharge detection
voltage (V
Short the VM pin and VSS pin, or
Set the VM pin’s voltage at the level of the charger detection voltage (V
discharge overcurrent detection voltage (V
The IC returns to the normal status.
2. When a charger is connected after overcharge detection, the overcharge status is not released
battery voltage does not fall below overcharge detection voltage (V
connected, discharge overcurrent detection and load short-circuiting detection do not function
until the battery voltage falls below overcharge detection voltage (V
has an internal impedance of tens of m , the battery voltage drops immediately after a heavy
load that causes overcurrent is connected, and discharge overcurrent detection and load short-
circuiting detection function.
even if the battery voltage is below overcharge release voltage (V
released when the VM pin voltage goes over charger detection voltage (V
charger.
CU
).
VMD
VMD
) between the VM pin and VDD pin, and the resistance (R
) between the VM pin and VDD pin, and the resistance (R
DL
) to overcharge detection voltage (V
Seiko Instruments Inc.
f
DIOV
voltage of the parasitic diode. This is because the discharge current
DIOV
), S-8211D Series releases the overcharge status when the battery
), the IC turns both the charging and discharging control FETs on.
DIOV
DIOV
), S-8211D Series releases the overcharge status when the
) or less by connecting the charger
CL
).
CU
CU
).
CU
), and the VM pin voltage is not more than
) or longer, the S-8211D Series turns the
VMS
VMS
) between the VM pin and VSS pin
) between the VM pin and VSS pin
CU
) during charging in the normal
CL
CU
CU
). The overcharge status is
) even when a heavy load is
). Since an actual battery
CHA
CHA
CHA
) or more and the
) by removing the
), and is lower than
Rev.4.9
CU
) and the
DIOV
_00
),