M61043FP

Rev.1.0, Sep.19.2003, page 3 of 34

Pin Function

Table 1

Pin No.

Symbol

Function

1

Vcc

The chip’s power supply pin. Power is supplied by the charger or the battery.

2

RESET

Output pin for microprocessor reset signal.

3

VIN_1

Positive input pin for lithium ion battery 1.

4

VIN_2

Negative input pin for lithium ion battery 1. Positive input pin for lithium ion battery 2.

5

VIN_3

Negative input pin for lithium ion battery 2. Positive input pin for lithium ion battery 3.

6

VIN_12

Charger connect monitor pin. Detects changes from power-down status.

7

DFOUT

Output pin for discharge FET on/off signals. Also turns off when overcurrent detected.

8

CFOUT

Output pin for charge FET on/off signals.

9

GND

Ground pin. Negative input pin for lithium ion battery 3. Connected to charge/discharge

current sensor resistor.

10

VIN_11

Charge/discharge current monitor pin. Connected to charge/discharge current sensor

resistor.

11

Analog_OUT

Output pin for analog signals.

12

CIN

Capacity connection pin for setting overcurrent prevention delay time.

13

CS

When this pin is low level, data input is accepted and data can be stored in a 6-bit shift

register. At the rising edge from low to high the value in the 6-bit shift register is

latched.

14

CK

Shift clock input pin. At the rising edge to high the input signal from the DI pin is input to

the 6-bit shift register.

15

DI

Shift data input pin. Serial data with a data length of 6 bits may be input via this pin.

16

Vreg

Power supply pin for microprocessor. Power can be shut off using a signal from the

microprocessor.

Operation

The M61043FP is an semiconductor IC device developed for smart battery packs. It is ideal for smart battery system

(SBS) battery packs that consist of four lithium ion batteries connected in series. A high-voltage device, it is suitable

for use with a wide variety of charger systems.

It incorporates all the analog circuitry required by smart batteries in a single chip. When used in conjunction with a

microprocessor, it allows the implementation of a variety of functions, such as battery capacity detection, through the

addition of minimal peripheral devices. The functions of the M61043FP are described below.

1. Battery Voltage Detect Circuit

The M61043FP can output the voltage levels of the batteries connected in series via the Analog_out pin. An on-chip

buffer amplifier monitors the pin voltages of the batteries. Offset voltage correction using adjustment by the

microprocessor is also supported. The M61043FP is configured to detect the battery voltage using a microprocessor

driven using a power supply voltage of 5.2 V.

2. Charge/Discharge Current Detect Circuit

SBS requires a function for monitoring the battery capacity. The M61043FP uses an on-chip amplifier to monitor

battery capacity based on a drop in the voltage of an external sensor resistor. In this way, the charge/discharge current is

converted into a voltage.

The voltage amplification ratio can be adjusted from the microprocessor. In addition, the current output shift voltage

can be adjusted from the microprocessor, widening the allowable dynamic range of the A/D converter.