S-8232 Datasheet, PDF (18/27 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK

BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK
S-8232 Series
Rev.5.4_00
„ Battery Protection IC Connection Example
R4
1 kΩ
R1
1 kΩ
Battery 1
C1
R2
1 kΩ
Battery 2
C2
EB+
SENS
VCC
0.22 µF
VC
S-8232 Series
0.22 µF
VSS
DO
FET1
CO
FET2
ICT
VM
R5
4.7 MΩ
R3
1 kΩ
Delay time setting
C3
0.22 µF
EB−
Figure 8
Table 8 Constants for External Components
Symbol
Parts
Purpose
Typ.
Min.
Max.
Remark
FET1
FET2
R1
C1
R2
C2
R4
C3
R3
R5
Nch MOS FET Discharge control
Nch MOS FET Charge control
Chip resistor ESD protection
Chip capacitor Filter
Chip resistor ESD protection
Chip capacitor Filter
Chip resistor ESD protection
Chip capacitor Delay time setting
Chip resistor
Protection for
charger reverse
connection
Chip resistor
0 V battery
charging inhibition


1 kΩ
0.22 µF
1 kΩ
0.22 µF
1 kΩ
0.22 µF
1 kΩ
(4.7 MΩ)


300 Ω
0 µF
300 Ω
0 µF
= R1 min.
0 µF
300 Ω
(1 MΩ)


1 kΩ
1 µF
1 kΩ
1 µF
= R1 max.
1 µF
5 kΩ
(10 MΩ)






Same value as R1 and R2. ^*1
Attention should be paid to leak
current of C3. ^*2
Discharge can’t be stopped at less
than 300 Ω when a charger is
reverse-connected. ^*3
R5 should be added when the
product has 0 V battery charge
inhibition. Lower resistance
increases current consumption. ^*4
*1. R4 = R1 is required. Overcharge detection voltage increases by R4. For example 10 kΩ (R4) increases overcharge
detection voltage by 20 mV.
*2. The overcharge detection delay time (t_CU), the overdischarge detection delay time (t_CD), and the over current detection
delay time (t_IOV) change with the external capacitor C3. Refer to the “„ Electrical Characteristics”.
*3. When the resistor R3 is set less than 300 Ω and a charger is reverse-connected, current which exceeds the power
dissipation of the package will flow and the IC may break. But excessive R3 causes increase of overcurrent detection
voltage 1 (V_IOV1). V_IOV1 changes to V_IOV1 = (R3 + R_VSM) / R_VSM × V_IOV1. For example, 50 kΩ resistor (R3) increases
overcurrent detection voltage 1 (V_IOV1) from 0.100 V to 0.113 V.
*4. A 4.7 MΩ resistor is needed for R5 to inhibit 0 V battery charging. Current consumption increases when the R5
resistance is below 4.7 MΩ. R5 should be connected when the product has 0 V battery charging inhibition.
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 through evaluation using the actual application to set the
constant.
18
Seiko Instruments Inc.