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

• Manufacturer Part Number: S-8241
• Description: Battery Protection IC for 1-Cell Pack
• Manufacturer: Seiko Instruments

Rev.4.1
Battery Protection IC Connection Example
*1. If an FET with a threshold voltage of 0.4 V or lower is used, the FET may fail to cut the charging current.
*2. If the withstand voltage between the gate and source is lower than the charger voltage, the FET may break.
*3. If R1 has a higher resistance than R2 and if a charger is connected reversely, current flows from the charger to the IC and the
*4. If a capacitor C1 is less than 0.0 1µF, DO may oscillate when load short-circuiting is detected, a charger is connected
*5. If R2 is set to less than 300 Ω, a current which is bigger than the power dissipation flows through the IC and the IC may break
Caution 1. The above constants may be changed without notice.
Symbol
FET1
FET2
R1
C1
R2
If an FET with a threshold voltage equal to or higher than the overdischarge detection voltage is used, discharging may stop
before overdischarge is detected.
voltage between VDD and VSS may exceed the absolute maximum rating. Install a resistor of 300 Ω or higher as R1 for ESD
protection.
If R1 has a high resistance, the overcharge detection voltage increases by IC current consumption.
reversely, or overcurrent 1 or 2 is detected.
A capacitor of 0.01 µF or higher as C1 should be installed. In some types of batteries DO oscillation may not stop unless the
C1 capacity is increased. Set the C1 capacity by evaluating the actual application.
when a charger is connected reversely. If a resistor bigger than 1.3 kΩ is installed as R2, the charging current may not be cut
when a high-voltage charger is connected.
_01
2. It has not been confirmed whether the operation is normal or not in circuits other than the above example of
Nch
MOS_FET
Nch
MOS_FET
connection. In addition, the example of connection shown above and the constant do not guarantee proper
operation. Perform through evaluation using the actual application to set the constant.
Capacitor
Resistor
Resistor
Parts
Battery
Protection for ESD and
power fluctuation
Protection for power
fluctuation
Protection for charger
reverse connection
Discharge control
Charge control
R1
470 Ω
0.1 µF
Purpose
Table 1 Constants for External Components
C1
VSS
VDD
FET1
Seiko Instruments Inc.
DO
0.1 µF
470 Ω
1 kΩ
Typ.


BATTERY PROTECTION IC FOR 1-CELL PACK
S-8241Series
Figure 11
FET2
CO
0.01 µF
300 Ω
300 Ω
min.


R2 value
1.0 µF
1.3 kΩ
max.
VM


1 kΩ
R2
0.4 V ≤ Threshold voltage ≤
overdischarge detection voltage.
Withstand voltage between gate and
source ≥ Charger voltage
0.4 V ≤ Threshold voltage ≤
overdischarge detection voltage.
Withstand voltage between gate and
source ≥ Charger voltage
Relation R1 ≤ R2 should be
maintained.
Install a capacitor of 0.01 µF or
higher between VDD and VSS.
To suppress current flow caused by
reverse connection of a charger, set the
resistance within the range from 300 Ω to
1.3 kΩ.
*5
*3
EB+
EB−
Remarks
S-8241 Series
*2
*2
*4
*1
*1
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