S-82B1AAA-I6T1U Datasheet, PDF (17/35 Pages) Seiko Instruments Inc – High-accuracy voltage detection circuit

BATTERY PROTECTION IC WITH CHARGE-DISCHARGE CONTROL FUNCTION FOR 1-CELL PACK
Rev.1.1_00
S-82B1A 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+ and EB− pins 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 charging current flows through the internal parasitic diode in the discharging control FET.
When the battery voltage becomes equal to or higher than V_DL, the S-82B1A Series enters the normal status.
Caution
1. Some battery providers do not recommend charging for a completely self-discharged lithium-ion
rechargeable 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.
8. 0 V battery charge function "unavailable"
This function inhibits charging 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 lithium-ion
rechargeable battery. Please ask the battery provider to determine whether to enable or inhibit the 0 V
battery charge function.
9. Delay circuit
The detection delay times are determined by dividing a clock of approximately 4 kHz by the counter.
Remark
t_DIOV1, t_DIOV2 and t_SHORT start when V_DIOV1 is detected. When V_DIOV2 or V_SHORT is detected over t_DIOV2 or t_SHORT
after the detection of V_DIOV1, the S-82B1A Series turns the discharge control FET off within t_DIOV2 or t_SHORT of
each detection.
V_DD
DO pin voltage
V_SS
V_DD
V_SHORT
VM pin voltage
VDIOV1
V_SS
t_SHORT
t_D
0 ≤ t_D ≤ t_SHORT
Time
Figure 9
Time
17