S-8241ACFMC-GCFT2G Seiko Instruments, S-8241ACFMC-GCFT2G Datasheet - Page 21

• Manufacturer Part Number: S-8241ACFMC-GCFT2G
• Description: IC LI-ION BATT PROTECT SOT23-5
• Manufacturer: Seiko Instruments

Specifications of S-8241ACFMC-GCFT2G

• Function: Over/Under Voltage Protection
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SC-74A, SOT-753
• Product: Li-Ion Protection
• Output Voltage: 4.295 V
• Operating Supply Voltage: 1.5 V to 8 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Rev.9.0
7. Delay Circuits
6. Abnormal Charge Current Detection
Caution 1. Counting for the overcurrent 2 detection delay time starts when the overcurrent 1 is detected.
If the VM pin voltage drops below the charger detection voltage (V
continues for the overcharge detection delay time (t
stops charging. This action is called abnormal charge current detection.
Abnormal charge current detection works when the discharging control FET is on (DO pin voltage is “H”) and the VM pin
voltage drops below the charger detection voltage (V
overdischarge status, the S-8241 consequently turns the charging control FET off and stops charging after the battery
voltage becomes the overdischarge detection voltage or higher (DO pin voltage becomes “H”) and the overcharge
detection delay time (t
Abnormal charge current detection is released when the voltage difference between VM pin and VSS pin becomes
lower than the charger detection voltage (V
Since the 0 V battery charging function has higher priority than the abnormal charge current detection function,
abnormal charge current may not be detected by the product with the 0 V battery charging function while the battery
voltage is low.
The detection delay times are determined by dividing a clock of approximately 2 kHz by the counter.
[Example] Overcharge detection delay time (= abnormal charge current detection delay time): 1.0 s
_00
Overdischarge detection delay time:
Overcurrent 1 detection delay time:
Overcurrent 2 detection delay time:
Having detected the overcurrent 1, if the overcurrent 2 is detected after the overcurrent 2 detection
delay time, the S-8241 turns the discharging control FET off as shown in the Figure 6. In this case,
the overcurrent 2 detection delay time may seem to be longer or overcurrent 1 detection delay time
may seem to be shorter than expected.
DO pin
VM pin
CU
) elapses.
V
V
V
V
V
V
DD
IOV2
IOV1
SS
DD
SS
Overcurrent 2 detection delay time (t
Seiko Instruments Inc.
CHA
) by separating the charger.
BATTERY PROTECTION IC FOR 1-CELL PACK
125 ms
CHA
CU
8 ms
2 ms
Figure 6
) or longer, the S-8241 turns the charging control FET off and
). When an abnormal charge current flows into a battery in the
CHA
) during charging under the normal status and it
IOV2
)
Time
Time
S-8241 Series
21