MITSMI MM1475 Datasheet

MITSUMI

Lithium Ion Battery Charging Control (microcomputer-controlled type) MM1475

Lithium Ion Battery Charging Control (microcomputer-controlled type)

Monolithic IC MM1475

Outline

This IC was developed as part of the MM1433 series of lithium ion battery charging ICs. MM1433 is a
charging IC with charging functions (quick charge, pre-charge) and all battery protection functions, while this
IC has charging control functions and some safety functions, with battery protection functions being
controlled by the external MPU.

Features

(1) Rated current, rated voltage charging
(2) Charging precision ± 30mV/cell (Ta = 0°C ~ +50°C)
(3) Pre-charge function and pre-charging over timer
(4) Input overvoltage, adaptor detection functions
(5) Battery temperature detection function

Package

TSOP-24A

Applications

Applications

(1) Mobile telephones
(2) PDA
(3) Movies
(4) Other equipment using lithium ion batteries

Pin Assignment

136924587101211

24 20 1723 21 19 18 1622 131415

TSOP-24A

1 SW1 13 BAT
2 SW2 14 CS

-

3 TP1 15 CS+
4 NC 16 CFB
5 VREF 17 CNT
6 GND1 18 V

CC

7 GND2 19 VOUT2
8 NC 20 V

OUT1

9 ADJ1 21 VDET

-

TD

10 CDO 22 NC
11 T

OUT 23 OSC OUT

12 TDET 24 OSC FB

-

MITSUMI

Lithium Ion Battery Charging Control (microcomputer-controlled type) MM1475

Block Diagram

SW1 SW2 Charging Current limit Timer

L H OFF OFF

H H ON Controlled by this IC (Current limit 2: 25mV) ON

LLON

Controlled by adaptor (Current limit 1: 450mV)

OFF

HLON

Controlled by adaptor (Current limit 1: 450mV)

OFF

MITSUMI

Lithium Ion Battery Charging Control (microcomputer-controlled type) MM1475

Pin Description

Pin No. Pin name I

/O Function

Function

1 SW1 Input

Charge control switching pin.
Switches charging ON/OFF and switches charging current by combinations
of SW1 and SW2 high and low.

2 SW2 Input

3 TP1

Input/output

Test pin 1.
Pre-charge timer test pin.
Inverts during counting (from the middle stage of the several-staged FF) and
outputs on TP1 for monitoring.
Also inverts TP1 output signal again inside the IC and inputs to the next stage FF.
(Timer setting done by binary counter.)
Reference power supply output pin.
Outputs 1.2V typ. reference voltage.

5 VREF Output

6 GND1 Input

Ground pin.

Ground pin.

7 GND2 Input

9 ADJ1 Input

Pre-charge current adjustment pin.
Pin voltage is set at 100mV typ.. Pre-charge current can be changed by
adjusting pin voltage with an external resistor.
Pre-charge current is controlled by comparing ADJ1 pin voltage and the 12dB
voltage drop value between CS + and CS

-

.

10 CDO Output

Current detection output pin.
Outputs voltage difference of 18dB between CS+ and CS

-

.

11 TOUT Output

Temperature detection output pin.
Normal temperature: Output Tr OFF
When high temperature is detected: Output Tr ON

12 TDET Input

Temperature detection input pin.
Be sure to apply the potential obtained by resistance dividing, from reference
voltage, with an external resistor and thermistor.

13 BAT Input

Battery voltage input pin.
Detects battery voltage and controls charging.

16 CFB Input

Rated current control phase compensation pin.
Oscillation is improved by connecting an external capacitor (around 100pF)
between CFB and CNT to perform phase compensation.

14 CS

-

Input

15 CS+ Input

Current detection pin.
Detects current by voltage drop at external resistor between (CS+) and (CS

-

)

and controls charging current.

17 CNT Output

Charging control output pin.
Controls base of external PNP-Tr for rated current rated voltage charging.

18 VCC Input

Power supply input pin.

19 VOUT2 Output

Adapter unplugged detection output pin.
V

CC low voltage input: Output Tr OFF

V

CC recommended operating voltage: Output Tr ON

20 VOUT1 Output

Overvoltage detection output pin.
V

CC overvoltage input: Output Tr OFF

V

CC recommended operating voltage: Output Tr ON

21 VDET-TD Input

Overvoltage detection delay time setting pin.
Delay time is set by connecting an external capacitor.

23 OSC OUT Output

Oscillator output pin.
Timer setting time changes according to oscillation frequency. Oscillation
frequency is determined by the external resistor (connected between OSC
OUT and OSC FB) and capacitor (connected between OSC FB and GND).

24 OSC FB

-

Input

Oscillator inverted input pin.

MITSUMI

Lithium Ion Battery Charging Control (microcomputer-controlled type) MM1475

Pin Description

The following valaeis typical

Pin No.

Pin name

Internal equivalent circuit diagram

Pin No.

Pin name

Internal equivalent circuit diagram

1 SW1

12 TDET

13 BAT

2 SW2

3 TP1

5 VREF

4 NC

8 NC

9 ADJ1

10 CDO

11 TOUT

14 CS

-

15 CS +

16 CFB

17 CNT

19 VOUT2