MITSMI MM1438 Datasheet

MITSUMI

1432

8567

VSOP-8B

MITSUMI

IC for Control of Lithium-ion Betteries Charging MM1438

IC for Control of Lithium-ion Betteries Charging

Monolithic IC MM1438

Outline

This IC is used to control charging of lithium-ion batteries consisting of a single cell. It is a modification of the previous MM1332 charging-control IC, with improved charging voltage accuracy and a smaller package.

Features

1. Charging voltage accuracy (Ta=25°C) ±25mV/cell

2. Charging voltage accuracy (Ta=0 to 50°C) ±30mV/cell

3. Consumption current (charging on) 250µA typ.

4. Consumption current (charging off) 2µA typ.

5. Low-voltage detection 2.15V typ.

6. Leakage current between CEL and CS 1µA max.

Package

VSOP-8B

Applications

IC for control of lithium-ion batteries charging.

Pin Assignment

1 GND

2 LV

3 SW2

4 SW1

5 V

6 EXT

7 CEL

8 CS

MITSUMI

Block Diagram

IC for Control of Lithium-ion Betteries Charging MM1438

Pin Description

Pin No. Pin name I/O

1 GND Input Ground pin

Low voltage detection circuit output pin

2 LV Output

ON with NPN-Tr open collector output at low voltage

Low voltage detection circuit ON/OFF control input pin

3 SW2 Input

SW2 = V

CC: OFF, SW2 = GND: ON

ON/OFF control input pin for the IC

4 SW1 Input

5 V

CC Input Power supply input pin

6 EXT Output

SW1 = V

Charging control output pin Controls external PNP-Tr to control charging.

CC: OFF, SW1 = GND: ON

Battery voltage input pin

7 CEL Input

Detects battery voltage and controls rated voltage to the prescribed voltage value.

Current detection pin

8 CS Input Detects current by drop in external resistor voltage and controls rated current.

Current value can be set at 0.1V/R1 typ.

Pin Description

MITSUMI

IC for Control of Lithium-ion Betteries Charging MM1438

Absolute Maximum Ratings

(Ta=25°C)

Item Symbol Ratings Unit

Storage temperature T

Operating temperature T

Power supply voltage V

CFL pin input voltage V

CC max.

CEL max.

SW input voltage V

Allowable loss Pd 300 mW

Recommended Operating Conditions

Item Symbol Ratings Unit

Operating temperature T

Charging control operating voltage

Note: Operating voltage minimum value is during rated current control.

STG

OPR

40~+125 °C

20~+70 °C

0.3~+18 V

0.3~+13 V

0.3~VCC+0.3 V

20~+70 °C

VOPR 2.5~+17 V

Electrical Characteristics

(Except where noted otherwise, Ta=25°C, VCC=5V, SW3 : A, SW6 : A, SW7 : A)

Item Symbol Measurement conditions Min. Typ. Max. Unit

Consumption current 1 I Consumption current 2 I

Output voltage 1 V Output voltage 2 V

Current limit V

CC1 VSW1=VSW2=0V (Charge : ON) 250 400 µA CC2 VSW1=VSW2=VCC (Charge : OFF) 2 10 µA

O1 Ta=25°C 4.100 4.125 4.150 V O2 Ta=0~50°C 4.095 4.125 4.155 V CL 90 100 110 mV

Inflow current between

CEL1 3.0 5.0 7.0 µA

CEL-CS during operation

Leak current between CEL-CS

SW1 input current I

SW1 input voltage L V

SW1 input voltage H V

Low voltage detection voltage

SW2 input current I

SW2 input current L V

SW2 input current H V

ICEL2 VCC=0V or OPEN 0.01 1 µA

SW1 20 30 µA

L1 Charge : ON

H1 Charge : OFF

0.3 2.0 V

VCC-

0.1 VCC+0.3

LV 2.0 2.15 2.3 V

SW2 20 30 µA

L2 Low voltage detection circuit: ON

H2 Low voltage detection circuit: OFF

0.3 2.0 V

VCC-

1.0 VCC+0.3

Low voltage detection

LV 0.5 µA

output leak current

Low voltage detection

LV ISINK=1mA 0.2 0.4 V

output saturation voltage

EXT pin inflow current IEXT 10 20 mA

EXT pin output voltage V

EXT For no load 0.3

VCC-

Note 1: Please insert a capacitor of several µF between power supply and ground when using.

Note 2: Be sure that CS pin potential does not fall below

0.5V.

Note 3: If the IC is damaged and control is no longer possible, its safety can not be guaranteed. Please

protect with something other than this IC.

0.3

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