Datasheet

BATTERY PROTECTION IC FOR SINGLE-CELL PACK
S-8261 Series
Rev.4.1_00
Seiko Instruments Inc.
22
7. Delay Circuits
The detection delay times are determined by dividing a clock of the approximately 3.5 kHz with the counter.
Remark 1. The detection delay time for overcurrent 2 (t
IOV2
) and load short-circuiting (t
SHORT
) start when the
overcurrent 1 (V
IOV1
) is detected. When the overcurrent 2 (V
IOV2
) or load short-circuiting (V
SHORT
) is
detected over the detection delay time for each of them (= t
IOV2
or t
SHORT
) after the detection of overcurrent
1 (V
IOV1
), the S-8261 Series turns the FET off within t
IOV2
or t
SHORT
of each detection.
DO pin
VM pin
V
DD
V
DD
Time
V
IOV1
V
SS
V
SS
V
IOV2
Overcurrent 2 detection delay time (t
IOV2
)
Time
t
D
0 ≤ t
D
≤ t
IOV2
Figure 6
2. For products with power-down function
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 (V
DL
). When the battery voltage falls below the
overdischarge detection voltage (V
DL
) due to the overcurrent, the S-8261 Series turns the discharging
control FET off by the 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 (t
DL
) is still lower than the
overdischarge detection voltage (V
DL
), the S-8261 Series shifts to the power-down condition.
For products without power-down function
When the overcurrent is detected and continues for longer than the overdischarge detection delay time
(t
DL
) without released the load, the condition changes to the overdischarge condition when the battery
voltage falls below overdischarge detection voltage (V
DL
).When the battery voltage falls below
overdischarge detection voltage (V
DL
) due to the overcurrent, the S-8261 Series turns the discharging
control FET off by the 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 (t
DL
) is still lower than the
overdischarge detection voltage (V
DL
), S-8261 Series shifts to the overdischarge condition.