S-8211DAD-M5T1X Datasheet, PDF (19/38 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

Rev.6.5_02
BATTERY PROTECTION IC FOR 1-CELL PACK
S-8211D Series
8. Delay circuit
The detection delay times are determined by dividing a clock of approximately 3.5 kHz by the counter.
Remark1. The discharge overcurrent detection delay time (tDIOV) and the load short-circuiting detection delay time
(tSHORT) start when the discharge overcurrent detection voltage (VDIOV) is detected. When the load short-
circuiting detection voltage (VSHORT) is detected over the load short-circuiting detection delay time (tSHORT)
after the detection of discharge overcurrent detection voltage (VDIOV), the S-8211D Series turns the
discharging control FET off within tSHORT from the time of detecting VSHORT.
V_DD
DO pin
t_D
V_SS
Load short-circuiting detection delay time (t_SHORT)
V_DD
VM pin
V_SHORT
V_DIOV
V_SS
Figure 10
0 ≤ t_D ≤ t_SHORT
Time
Time
2. With power-down function
When any overcurrent is detected and the overcurrent continues for longer than the overdischarge
detection delay time (tDL) without the load being released, the status changes to the power-down status at
the point where the battery voltage falls below overdischarge detection voltage (VDL).
When the battery voltage falls below overdischarge detection voltage (VDL) due to overcurrent, the
S-8211D Series turns the discharging control FET off via overcurrent detection. In this case, if the recovery
of the battery voltage is so slow that the battery voltage after the overdischarge detection delay time (tDL) is
still lower than the overdischarge detection voltage (VDL), the S-8211D Series shifts to the power-down
status.
Without power-down function
When any overcurrent is detected and the overcurrent continues for longer than the overdischarge
detection delay time (tDL) without the load being released, the status changes to the overdischarge status
at the point where the battery voltage falls below overdischarge detection voltage (VDL).
When the battery voltage falls below overdischarge detection voltage (VDL) due to overcurrent, the
S-8211D Series turns the discharging control FET off via overcurrent detection. In this case, if the recovery
of the battery voltage is so slow that the battery voltage after the overdischarge detection delay time (tDL) is
still lower than the overdischarge detection voltage (VDL), the S-8211D Series shifts to the overdischarge
status.
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