S-8200AAC-M6T1U Datasheet, PDF (15/36 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 1-CELL PACK

Rev.4.0_02
BATTERY PROTECTION IC FOR 1-CELL PACK
S-8200A Series
2. 2 VCL = VCU (Product in which overcharge release voltage is the same as overcharge detection voltage)
When the battery voltage becomes higher than VCU during charging in the normal status and detection continues for
tCU or longer, the S-8200A Series turns the charge control FET off to stop charging. This condition is called the
overcharge status.
RVMD and RVMS are not connected in the overcharge status.
The overcharge status is released in the following two cases.
(1) In the case that the VM pin voltage is higher than or equal to VCIOV, and is lower than VDIOV, the S-8200A Series
releases the overcharge status when the battery voltage falls below VCL.
(2) In the case that the VM pin voltage is higher than or equal to VDIOV, the S-8200A Series releases the overcharge
status when the battery voltage falls below VCU.
When the discharge is started by connecting a load after the overcharge detection, the VM pin voltage rises by the Vf
voltage of the parasitic diode than the VSS pin voltage, because the discharge current flows through the parasitic
diode in the charging control FET. If this VM pin voltage is higher than or equal to VDIOV, the S-8200A Series releases
the overcharge status when the battery voltage is lower than or equal to VCU.
For the actual application boards, changing the battery voltage and the charger voltage simultaneously enables to
measure VCL. In this case, the charger is always necessary to have the equivalent voltage level to the battery
voltage. The charger keeps VM pin voltage higher than or equal to VCIOV and lower than or equal to VDIOV. The
S-8200A Series releases the overcharge status when the battery voltage falls below VCL.
Caution
1. If the battery is charged to a voltage higher than VCU and the battery voltage does not fall below VCU
even when a heavy load is connected, discharge overcurrent detection and load short-circuiting
detection do not function until the battery voltage falls below VCU. Since an actual battery has an
internal impedance of tens of mΩ, the battery voltage drops immediately after a heavy load that
causes overcurrent is connected, and discharge overcurrent detection and load short-circuiting
detection function.
2. When a charger is connected after overcharge detection, the overcharge status is not released
even if the battery voltage is below VCL. The overcharge status is released when the VM pin voltage
goes over VCIOV by removing the charger.
3. Overdischarge status
When the battery voltage falls below overdischarge detection voltage (VDL) during discharging in the normal status and
the detection continues for the overdischarge detection delay time (tDL) or longer, the S-8200A Series turns the discharge
control FET off to stop discharging. This condition is called the overdischarge status.
Under the overdischarge status, the VM pin and VDD pin are shorted by RVMD in the S-8200A Series. The VM pin
voltage is pulled up by RVMD.
When a battery in the overdischarge status is connected to a charger and provided that the VM pin voltage is lower than
−0.7 V typ., the S-8200A Series releases the overdischarge status when the battery voltage reaches VDL or higher.
When VM pin voltage is not lower than −0.7 V typ., the S-8200A Series releases the overdischarge status when the
battery voltage reaches VDU or higher.
RVMS is not connected in the overdischarge status.
3. 1 With power-down function
Under the overdischarge status, when voltage between the VDD pin and VM pin is 0.8 V typ. or lower, the power-
down function works and the current consumption is reduced to the current consumption during power-down (IPDN).
By connecting a battery charger, the power-down function is released when the VM pin voltage is 0.7 V typ. or lower.
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