S-8211DAD-M5T1X Datasheet, PDF (24/38 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC FOR 1-CELL PACK
S-8211D Series
 Battery Protection IC Connection Example
R1
VDD
Battery C1
S-8211D Series
Rev.6.5_02
EB+
VSS
DO
CO
VM
R2
FET1
FET2
EB−
Figure 15
Table 14 Constants for External Components
Symbol Part
Purpose
Min.
Typ.
Max.
Remark
FET1
N-channel
MOS FET
Discharge control
Threshold voltage ≤ Overdischarge detection
voltage^*1
−
−
−
Gate to source withstand voltage ≥ Charger
voltage^*2
FET2
N-channel
MOS FET
Charge control
Threshold voltage ≤ Overdischarge detection
voltage^*1
−
−
−
Gate to source withstand voltage ≥ Charger
voltage^*2
R1
Resistor
ESD protection,
For power fluctuation
100 Ω
220 Ω
330 Ω
Resistance should be as small as possible to
avoid lowering the overcharge detection
accuracy due to current consumption.^*3
C1
Capacitor For power fluctuation
0.022 μF 0.1 μF
1.0 μF
Connect a capacitor of 0.022 μF or higher
between VDD pin and VSS pin.^*4
R2
Resistor
Protection for reverse
connection of a charger
300 Ω
2 kΩ
4 kΩ
Select as large a resistance as possible to
prevent current when a charger is connected
in reverse.^*5
*1. If the threshold voltage of an FET is low, the FET may not cut the charge 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.
*2. If the withstand voltage between the gate and source is lower than the charger voltage, the FET may be destroyed.
*3. If a high resistor is connected to R1, the voltage between the VDD pin and the VSS pin may exceed the absolute
maximum rating when a charger is connected in reverse since the current flows from the charger to the IC. Insert a
resistor of 100 Ω or higher as R1 for ESD protection.
*4. If a capacitor of less than 0.022 μF is connected to C1, the DO pin may oscillate when load short-circuiting is detected. Be
sure to connect a capacitor of 0.022 μF or higher to C1.
*5. If a resistor of 4 kΩ or higher is connected to R2, the charging current may not be cut when a high-voltage charger is
connected.
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.
24