BATTERY PROTECTION IC FOR 3-SERIAL-CELL PACK

S-8233A Series

Seiko Instruments Inc.

2

Block Diagram

Battery 1

Over charge

Battery 3

Over discharge

Battery 3

Over charge

Battery 2

Over charge

Battery 2

Over discharge

Over charge

delay circuit

Battery 1

Over discharge

Battery 3

Over charge

Battery 2

Over charge

Battery 1

Over charge

Reference

voltage 3

Reference

voltage 2

Reference

voltage 1

Control

Logic

Over current

detection

circuit

Over discharge

delay circuit

Over current1,

delay circuit

Over current

2,3 delay

circuit

−

+

−

+

−

+

−

+

−

+

−

+

DOP

VMP

COVT

CDT

CCT

COP

CTL

VSS

CD3

VC2

CD2

CD1

VC1

VCC

Floating

detection circuit

Figure 1

Remark The delay time for over current detection 2 and 3 is fixed by an internal IC circuit. The delay time

cannot be changed via an external capacitor.