S-8250BAB-I6T1U Datasheet, PDF (16/32 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 1-CELL PACK

BATTERY PROTECTION IC FOR 1-CELL PACK
S-8250B Series
Rev.1.1_02
6. 0 V battery charge function "available"
This function is used to recharge a connected battery whose voltage is 0 V due to self-discharge. When the 0 V
battery charge starting charger voltage (V_0CHA) or a higher voltage is applied between the EB+ pin and EB− pin by
connecting a charger, the charge control FET gate is fixed to the VDD pin voltage. When the voltage between the
gate and source of the charge control FET becomes equal to or higher than the threshold voltage due to the charger
voltage, the charge control FET is turned on to start charging. At this time, the discharge control FET is off and the
charge current flows through the internal parasitic diode in the discharge control FET. When the battery voltage
becomes equal to or higher than V_DU, the S-8250B Series enters the normal status.
Caution
1. Some battery providers do not recommend charging for a completely self-discharged battery.
Please ask the battery provider to determine whether to enable or inhibit the 0 V battery charge
function.
2. The 0 V battery charge function has higher priority than the charge overcurrent detection
function. Consequently, a product in which use of the 0 V battery charge function is enabled
charges a battery forcibly and the charge overcurrent cannot be detected when the battery
voltage is lower than V_DL.
7. 0 V battery charge function "unavailable"
This function inhibits recharging when a battery that is internally short-circuited (0 V battery) is connected. When the
battery voltage is the 0 V battery charge inhibition battery voltage (V_0INH) or lower, the charge control FET gate is
fixed to the EB− pin voltage to inhibit charging. When the battery voltage is V_0INH or higher, charging can be
performed.
Caution Some battery providers do not recommend charging for a completely self-discharged battery.
Please ask the battery provider to determine whether to enable or inhibit the 0 V battery charge
function.
8. Delay circuit
The detection delay times are determined by dividing a clock of approximately 4 kHz by the counter.
Remark t_DIOV and t_SHORT start when V_DIOV is detected. When V_SHORT is detected over t_SHORT after V_DIOV, the S-8250B
Series turns the discharge control FET off within t_SHORT from the time of detecting V_SHORT.
V_DD
DO pin voltage
V_SS
V_DD
V_SHORT
VM pin voltage
V_DIOV
V_SS
t_SHORT
t_D
0 ≤ t_D ≤ t_SHORT
Time
Figure 9
Time
16