AIC1821

ONE-CELL LITHIUM-ION BATTERY PROTECTION IC

SPEC NO: DS-1821-P1 06/07/00

ANALOG INTEGRATIONS CORPORATION

www.analog.com.tw

4F, 9 Industry E. 9th Road, Science-based IndustrialPark,Hsinchu,Taiwan, R.O.C.

TEL: (8863)577-2500

FAX:(8863)577-2510

4

Power-down

Control

Wake-up Control

-0.3V

3

4

1

2

5

VCC

Overdischarge

Delay Circuit

Overcharge

Delay Circuit

Overcurrent

Delay Circuit

Enable

Enable

Load Detected

0.3V

0.2V

CS

GND

OC

OD

1.2V

1V

PIN 1:

OC

- PMOS open drain output for control

of the charge control MOSFET M2. In

normal mode, this PMOS turns on to

pull the gate of the MOSFET M2 to

high, then the MOSFET M2 turns on.

When overcharge occurs, this PMOS

turns

off,

then

no

current

flows

through R3 and the MOSFET M2

turns off.

PIN 2:

GND - Ground

pin.

This

pin

is

to

be

connected to the negative terminal of

the battery cell.

PIN 3:

OD

- Output

pin

for

control

of

the

discharge

control

MOSFET

M1.

When overdischarge occurs, this pin

goes low to turn off the MOSFET M1

and discharging is inhibited.

PIN 4:

CS

- Input pin for current sensing. Using

the sum of drain-source voltages of

the MOSFET M1 and the MOSFET

M2 (voltage between CS and GND),

it senses discharge current during

normal mode and detects whether

charge

current

is

present

during

power-down mode. It also used to

detect whether load is connected

during overcharge mode.

PIN 5:

VCC - Power supply pin. This pin is to be

connected to the positive terminal of

the battery cell.