MITSUMI

Protection of Lithium Ion Batteries (two cells in series) MM1292

Pin Assignment

14

3

2

85

6

7

SOP-8C/SOP-8D

1

OC

2

GD

3

N.C

4

GND

5

TD

6

VL

7

CS

8

VH

Pin Description

Pin No.

Pin

Output

Function

1

OC

Output

2

GD

Output

3

DS

Input

4

GND

Input

5

TD

Input

6

VL

Input

7

CS

Input

8

VH

Input

Output pin for control of the charging control FET. When voltage detected between

VH-VL or VL-GND goes over overcharge detection voltage (VALM), the output PNP-

TR (open collector output) is switched ON, and charging is prohibited by activating

the element (NPN-TR, or N-ch FET) that switches the charging control FET to OFF.

This operation continues until the voltage falls below VALM.

Output pin for driving the discharge control FET. When voltage detected between VH-

VL and VL-GND goes over excess discharge voltage (VS), this pin goes H. When

voltage detected between VH-VL and VL-GND falls below VS and the voltage between

CS-GND is more than the voltage detected for an overcurrent (VCS), it goes L.

Input pin for discharge detection. When voltage between DS-GND during charge

detection exceeds discharge detection voltage (VDS), OC output is switched OFF

and charge control FET is switched ON.

Negative connection pin for the low side battery. It is also the GND pin for this IC.

(The IC's reference power supply pin.)

Over charge detection output non-induction time setting pin. The capacitor connected

between TD-GND is charged with constant current (ITC) during over charging. When

TC pin voltage exceeds the threshold value (VTC), OC output is switched ON.

Positive connection pin for the low side battery, and negative connection pin for the

high side battery.

Overcurrent detection pin during discharge, and charging detection pin during

power down. It detects discharge current using the source drain voltage (voltage

between CS-GND) of discharge control FET. Also, when the battery is charged with

a current whose CS-GND voltage after power down exceeds the start-up voltage

(VST), the bias current is drained to the interior circuit and operating status results.

Positive connection pin for the high side battery, and the IC's current input pin.

Applications

1. Cellular phones

2. Movies