S-8250AAB-I6T1U Datasheet, PDF (17/36 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

Rev.1.3_02
BATTERY PROTECTION IC WITH DISCHARGE CONTROL FUNCTION FOR 1-CELL PACK
S-8250A Series
6. Discharge inhibition status
6. 1 CTL pin control logic active "H"
When a battery in the normal status is in the status where CTL pin voltage is equal to or higher than CTL pin
voltage "H" (V_CTLH) and the status lasts for discharge inhibition delay time (t_CTL) or longer, the discharge control
FET is turned off and discharging is stopped. This status is called the discharge inhibition status.
6. 1. 1 Discharge inhibition status latch function "available"
If CTL pin voltage is equal to or lower than CTL pin voltage "L" (V_CTLL), the S-8250A Series releases
discharge inhibition status when the VM pin voltage becomes equal to or lower than V_DIOV by connecting
a charger.
6. 1. 2 Discharge inhibition status latch function "unavailable"
The S-8250A Series releases discharge inhibition status when the CTL pin voltage becomes equal to or
lower than V_CTLL.
6. 2 CTL pin control logic active "L"
When a battery in the normal status is in the status where CTL pin voltage is equal to or lower than CTL pin
voltage "L" (V_CTLL) and the status lasts for discharge inhibition delay time (t_CTL) or longer, the discharge control
FET is turned off and discharging is stopped. This status is called the discharge inhibition status.
6. 2. 1 Discharge inhibition status latch function "available"
If CTL pin voltage is equal to or higher than CTL pin voltage "H" (V_CTLH), the S-8250A Series releases
discharge inhibition status when the VM pin voltage becomes equal to or lower than V_DIOV by connecting
a charger.
6. 2. 2 Discharge inhibition status latch function "unavailable"
The S-8250A Series releases discharge inhibition status when the CTL pin voltage becomes equal to or
higher than V_CTLH.
In discharge inhibition status, if the battery voltage exceeds V_CU by connecting a charger, the S-8250A Series
releases discharge inhibition status.
The CTL pin is shorted to the VDD pin or VSS pin by the CTL pin internal resistance (R_CTL) in the S-8250A Series.
When the voltage between the VDD pin and VM pin is 0.8 V typ. or lower in the overdischarge status, R_CTL is
disconnected and the input and output current to the CTL pin is cut off.
The discharge control by the CTL pin does not function in the overcharge status and the charge overcurrent status.
In the discharge inhibition status, the VM pin and VDD pin are shorted by R_VMD in the S-8250A Series.
7. 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-8250A 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.
17