S-8250BAB-I6T1U Datasheet, PDF (15/32 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 1-CELL PACK

Rev.1.1_02
BATTERY PROTECTION IC FOR 1-CELL PACK
S-8250B Series
3. Overdischarge status
When the battery voltage falls below V_DL during discharging in the normal status and the condition continues for the
overdischarge detection delay time (t_DL) or longer, the S-8250B Series turns the discharge control FET off to stop
discharging. This condition is called the overdischarge status.
Under the overdischarge status, VDD pin and VM pin are shorted by R_VMD in the S-8250B Series. The VM pin voltage
is pulled up by R_VMD.
R_VMS is not connected in the overdischarge status.
3. 1 With power-down function
Under the overdischarge status, when voltage difference between 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 (I_PDN). By connecting a battery charger, the power-down function is released when the VM pin voltage is
0.7 V typ. or lower.
• When a battery is not connected to a charger and the VM pin voltage ≥ 0.7 V typ., the S-8250B Series
maintains the overdischarge status even when the battery voltage reaches V_DU or higher.
• When a battery is connected to a charger and 0.7 V typ. > the VM pin voltage > 0 V typ., the battery voltage
reaches V_DU or higher and the S-8250B Series releases the overdischarge status.
• When a battery is connected to a charger and 0 V typ. ≥ the VM pin voltage, the battery voltage reaches V_DL or
higher and the S-8250B Series releases the overdischarge status.
3. 2 Without power-down function
Under the overdischarge status, the power-down function does not work even when voltage difference between
VDD pin and VM pin is 0.8 V typ. or lower.
• When a battery is not connected to a charger and the VM pin voltage ≥ 0.7 V typ., the battery voltage reaches
V_DU or higher and the S-8250B Series releases the overdischarge status.
• When a battery is connected to a charger and 0.7 V typ. > the VM pin voltage > 0 V typ., the battery voltage
reaches V_DU or higher and the S-8250B Series releases the overdischarge status.
• When a battery is connected to a charger and 0 V typ. ≥ the VM pin voltage, the battery voltage reaches V_DL or
higher and the S-8250B Series releases the overdischarge status.
4. Discharge overcurrent status (Discharge overcurrent, load short-circuiting)
When a battery in the normal status is in the status where the VM pin voltage is equal to or higher than V_DIOV because
the discharge current is equal to or higher than the specified value and the status lasts for the discharge overcurrent
detection delay time (t_DIOV) or longer, the discharge control FET is turned off and discharging is stopped. This status
is called the discharge overcurrent status.
4. 1 Release condition of discharge overcurrent status "load disconnection"
In the discharge overcurrent status, the VM pin and VSS pin are shorted by R_VMS in the S-8250B Series.
However, the VM pin voltage is the VDD pin voltage due to the load as long as the load is connected. When the
load is disconnected, the VM pin voltage returns to the VSS pin voltage. If the VM pin voltage returns to the
discharge overcurrent release voltage (V_RIOV) or lower, the S-8250B Series releases the discharge overcurrent
status.
R_VMD is not connected in the discharge overcurrent status.
4. 2 Release condition of discharge overcurrent status "charger connection"
In the discharge overcurrent status, the VM pin and VDD pin are shorted by R_VMD in the S-8250B Series.
If the VM pin voltage returns to V_DIOV or lower by connecting a charger, the S-8250B Series releases the
discharge overcurrent status.
R_VMS is not connected in the discharge overcurrent status.
5. Charge overcurrent status
When a battery in the normal status is in the status where the VM pin voltage is equal to or lower than V_CIOV because
the charge current is equal to or higher than the specified value and the status lasts for the charge overcurrent
detection delay time (t_CIOV) or longer, the charge control FET is turned off and charging is stopped. This status is
called the charge overcurrent status.
The S-8250B Series releases the charge overcurrent status when the VM pin voltage returns to 0 V typ. or higher by
removing the charger.
The charge overcurrent detection does not function in the overdischarge status.
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