BATTERY PROTECTION IC FOR 1-CELL PACK

S-8240B Series

21



Battery Protection IC Connection Example

R1

Battery C1

VSS

DO

VDD

CO

VM

S-8240B Series

FET1

FET2

EB

−

EB

+

R2

Figure 15

Table 11 Constants for External Components

Symbol

Part

Purpose

Min.

Typ.

Max.

Remark

FET1

N-channel

MOS FET

Discharge control

−

−

−

Threshold voltage

≤ Overdischarge

detection voltage

*1

FET2

N-channel

MOS FET

Charge control

−

−

−

Threshold voltage

≤ Overdischarge

detection voltage

*1

R1

Resistor

ESD protection,

For power fluctuation

270

Ω

330

Ω

1 k

Ω

−

C1

Capacitor

For power fluctuation

0.068

μF

0.1

μF

1.0

μF

Caution should be exercised when setting

*2

R2

Resistor

ESD protection,

Protection for reverse

connection of a charger

300

Ω

470

Ω

4 k

Ω

Caution should be exercised when

an FET with a large gate capacitance is

used.

*3

*1. 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.

be met.

*3. If an FET with a gate capacitance equal to or more than 5 nF is used, charge overcurrent detection voltage may become

lower when R2 resistance is large. R2 resistance should be set to a smaller value when an FET with a gate capacitance

equal to or more than 5 nF is used.

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.