BATTERY PROTECTION IC FOR 1-CELL PACK

S-8211C Series

28



Battery Protection IC Connection Example

R1

Battery C1

VSS

DO

VDD

CO

VM

S-8211C Series

FET1

FET2

EB



EB



R2

Figure 14

Table 20 Constants for External Components

Symbol

Part

Purpose

Min.

Typ.

Max.

Remark

FET1

N-channel

MOS FET

Discharge control







Threshold voltage

 Overdischarge

detection voltage

*1

P

Gate to source withstand voltage



Charger voltage

P

*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



220



330



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

F

0.1

F

1.0

F

Connect a capacitor of 0.022

F or

higher between VDD pin and VSS pin.

*4

R2

Resistor

Protection for reverse

connection of a

charger

300



2 k



2 k



Select as large a resistance as possible

to prevent current when a charger is

connected in reverse.

*5

*1. If the threshold voltage of a FET is low, the FET may not cut the charge current. If a 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

 or higher as R1 for ESD protection.

*4. If a capacitor of less than 0.022

F is connected to C1, DO pin may oscillate when load short-circuiting is detected. Be

sure to connect a capacitor of 0.022

F or higher to C1.

*5. If a resistor of 2 k

 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.