S-8262AAA-I8T1U Datasheet, PDF (24/36 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK
S-8262A Series
Rev.1.0_02
 Battery Protection IC Connection Example
Battery 1
Battery 2
R1
C1
VDD
R2
VC
C2
S-8262A Series
EB+
R4
AO
DP
VSS
DO
CO
VM
R3
FET1
FET2
EB−
Figure 15
Table 10 Constants for External Components
Symbol
Part
Purpose
Typ.
Min.
Max.
Remark
Threshold voltage ≤ Overdischarge
FET1
Nch
MOS FET
Discharge control
−
−
detection voltage^*2
−
Gate to source withstanding voltage ≥
Charger voltage^*3
FET2
Nch
MOS FET
Charge control
Threshold voltage ≤ Overdischarge
detection voltage^*2
−
−
−
Gate to source withstanding voltage ≥
Charger voltage^*3
Resistance should be as small as
R1, R2 Resistor
ESD protection,
For power fluctuation
470 Ω
150 Ω^*1
1 kΩ^*1
possible to avoid lowering the
overcharge detection accuracy due to
current consumption.^*4
C1, C2 Capacitor
For power fluctuation
0.1 μF
0.068 μF^*1
1.0 μF^*1
Connect a capacitor of 0.068 μF or
higher between VDD pin and VSS pin.^*5
Protection for
Select as large a resistance as possible
R3
Resistor reverse connection
2 kΩ
300 Ω^*1
4 kΩ^*1 to prevent current when a charger is
of a charger
connected in reverse.^*6
R4
Resistor Pull up resistor
47 kΩ
−
−
−
*1. Please set up a filter constant to be R1 × C1 = R2 × C2.
*2. If the threshold voltage of an FET is low, the FET may not cut the charging current. If an FET with a threshold voltage
equal to or higher than the overdischarge detection voltage is used, discharging may be stopped before overdischarge
is detected.
*3. If the withstanding voltage between the gate and source is equal to or lower than the charger voltage, the FET may be
destroyed.
*4. An accuracy of overcharge detection voltage is guaranteed by R1 = 470 Ω. Connecting resistors with other values
worsen the accuracy. In case of connecting larger resistor to R1, the voltage between the VDD pin and VSS pin may
exceed the absolute maximum rating because the current flows to the IC from the charger due to reverse connection
of charger. Connect a resistor of 150 Ω or more to R1 for ESD protection.
*5. When connecting a resistor of 150 Ω or less to R1 or R2 or a capacitor of 0.068 μF or less to C1 or C2, the IC may
malfunction when power dissipation is largely fluctuated.
*6. When a resistor of 4 kΩ or more is connected to R3, the charge current may not be cut.
Caution 1. The above constants may be changed without notice.
2. It has not been confirmed whether the operation is normal or not in circuits other than the above
example of connection. In addition, the example of connection shown above and the constant do not
guarantee proper operation. Perform thorough evaluation using the actual application to set the
constant.
3. Do not connect a resistor to the DP pin during normal use.
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