S-8211CAA-M5T1X Datasheet, PDF (28/43 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC FOR 1-CELL PACK
S-8211C Series
 Battery Protection IC Connection Example
Rev.7.7_02
EB+
R1
VDD
Battery C1
S-8211C Series
VSS
DO
CO
VM
R2
FET1
FET2
EB−
Figure 14
Table 20 Constants for External Components
Symbol Part
Purpose
Min.
Typ.
Max.
Remark
FET1
N-channel
MOS FET
Discharge control
FET2
N-channel
MOS FET
Charge control
Threshold voltage ≤ Overdischarge
detection voltage^*1
−
−
−
P
Gate to source withstand voltage ≥
Charger voltage*2
P
Threshold voltage ≤ Overdischarge
detection voltage^*1
−
−
−
Gate to source withstand voltage ≥
Charger voltage^*2
Resistance should be as small as
R1
Resistor
ESD protection,
For power fluctuation
100 Ω
220 Ω
330 Ω
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
Protection for reverse
Select as large a resistance as possible
R2
Resistor connection of a
charger
300 Ω
2 kΩ
2 kΩ
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 VDD pin and 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, 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 2 kΩ or higher is connected to R2, the charge 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.
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