s-8261aajmd Seiko Instruments Inc., s-8261aajmd Datasheet - Page 24

• Manufacturer Part Number: s-8261aajmd
• Description: Battery Protection Ic For Single-cell Pack
• Manufacturer: Seiko Instruments Inc.

**2. If the withstanding voltage between the gate and source is lower than the charger voltage, the FET may be destroyed.
24
*1. If the threshold voltage of an FET is low, the FET may not cut the charging current.
*3. If R1 has a high resistance, the voltage between VDD and VSS may exceed the absolute maximum rating when a
*4. If a capacitor of less than 0.022 µF is connected to C1, DO may oscillate when load short-circuiting is detected.
*5. If R2 has a resistance higher than 4 kΩ, the charging current may not be cut when a high-voltage charger is
BATTERY PROTECTION IC FOR SINGLE-CELL PACK
S-8261 Series
FET1
FET2
R1
C1
R2
Caution 1. The above constants may be changed without notice.
Symbol
Battery Protection IC Connection Example
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.
charger is connected in reverse since the current flows from the charger to the IC. Insert a resistor of 300 Ω or higher
to R1 for ESD protection.
sure to connect a capacitor of 0.022 µF or higher to C1.
connected.
N-channel
MOS FET
N-channel
MOS FET
Resistor
Capacitor
Resistor
2. The DP pin should be open.
3. It has not been confirmed whether the operation is normal or not in circuits other than the above
Part
example of connection. In addition, the example of connection shown above and the constant do not
guarantee proper operation.
constant.
Discharge control
Charge control
ESD protection,
For power fluctuation
For power fluctuation
Protection for reverse
connection of a charger
Purpose
Battery C1 :
R1 : 470 Ω
0.1 µF
Table 17 Constant for External Components
VDD
VSS
0.1 µ F
470 Ω
2 k Ω
Typ.


Perform through evaluation using the actual application to set the
DO
Seiko Instruments Inc.
FET1
0.022 µ F
300 Ω
300 Ω
S-8261 Series
Min.


Figure 10
CO
1.0 µ F
Max.
1 k Ω
4 k Ω
FET2


Threshold voltage ≤ Overdischarge detection voltage
Gate to source withstanding voltage ≥ Charger voltage
Threshold voltage ≤ Overdischarge detection voltage
Gate to source withstanding voltage ≥ Charger voltage
Resistance should be as small as possible to avoid lowering of
the overcharge detection accuracy caused by VDD pin current.
Install a capacitor of 0.022 µ F or higher between VDD and VSS.
Select a resistance as large as possible to prevent large current
when a charger is connected in reverse.
VM
R2 : 2 kΩ
DP
EB+
EB−
Remarks
*5
Rev.4.4
*1
*1
*2
*2
_00
Be
*3
*4