S-8242B Datasheet, PDF (13/30 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK

Rev.1.4_00
BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK
S-8242B Series
8. Delay Circuit
The detection delay times are determined by dividing a clock of approximately 3.5 kHz by the counter.
Remark1.
The overcurrent detection delay time 2 (t_IOV2) starts when the overcurrent detection voltage 1 (V_IOV1) is
detected. When the overcurrent detection voltage 2 (V_IOV2) is detected over the overcurrent detection
delay time 2 (t_IOV2) after the detection of overcurrent detection voltage 1 (V_IOV1), the S-8242B turns the
discharging control FET off within t_IOV2 from the time of detecting V_IOV2.
V_DD
DO pin
t_D
V_SS
Overcurrent detection delay time 2 (t_IOV2)
V_DD
VM pin
V_IOV2
V_IOV1
V_SS
0≦t_D≦t_IOV2
Time
Time
Figure 9
2. When the overcurrent is detected and continues for longer than the overdischarge detection delay time
(t_DL) without releasing the load, the condition changes to the power-down condition when the battery
voltage falls below the overdischarge detection voltage n (V_DLn). When the battery voltage falls below the
overdischarge detection voltage n (V_DLn) due to the overcurrent, the S-8242B Series turns the discharging
control FET off by the overcurrent detection. In this case the recovery of the battery voltage is so slow that
if the battery voltage after the overdischarge detection delay time (t_DL) is still lower than the overdischarge
detection voltage n (V_DLn), the S-8242B Series shifts to the power-down condition.
Seiko Instruments Inc.
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