AIC1803

8

PIN 1: OC-

NMOS open drain output

for

control

of

the

charge

control

MOSFET M2. When overcharge

occurs, this pin sinks current to

switch the external PNP Q1 on,

and

charging

is

inhibited

by

turning off the charge

control

MOSFET M2.

PIN 2: CS-

Input pin for current sensing.

Using the drain-source voltage of

the

discharge

control

MOSFET

M1 (voltage between

VCC

and

CS),

it

senses

discharge

current

during

normal

mode

and

detects

whether charging

current

is

present

during

power-down

mode.

PIN 3: OD -

Output pin for control of discharge control MOSFET M1.

When overdischarge occurs, this pin goes high to turn off the discharge control MOSFET M1

PIN 4: NC -

No connection

PIN 5: TD-

Overdischarge delay time setting

pin.

PIN 6: TI -

Overcurrent

delay

time setting

pin.

PIN 7: TC -

Overcharge

delay time setting

pin.

PIN 8: NC -

No connection.

PIN 9: GND -

Ground pin. This pin is to be

connected

to

the

negative

terminal of the battery cell BAT3.

PIN10: UD3 -

This pin is to be connected to the

positive

terminal

of the battery

cell BAT3

for

cell-balancing

bleeding

function

under

overcharge condition.

PIN11: VC3-

Input

pin

for

battery

BAT3

voltage sensing. This pin is to be

connected

to

the

positive

terminal of the battery cell BAT3.

PIN12: UD2 -

This pin is to be connected to the

positive terminal of the battery

cell

BAT2

for

cell-balancing

bleeding

function

under

overcharge condition.

PIN13: VC2-

Input

pin

for

battery

BAT2

voltage sensing. This pin is to be

connected

to

the

positive

terminal of the battery cell BAT2.

PIN14: UD1-

This pin is to be connected to the positive terminal of the

PIN15: VC1-

Input

pin

for

battery

BAT1

voltage sensing. This pin is to be

connected

to

the

positive

terminal of the battery cell BAT1.

PIN16: VCC -

Power supply pin. This pin is to

be

connected

to

the

positive

terminal of the battery cell BAT1.

l THE OPERATION

Initialization

On initial power-up , such as connecting the

battery pack for the first time to the AIC1803 , the

AIC1803 enters the power-down mode . A charger

must be applied to the AIC1803 circuit to enable

the pack.

Overcharge Protection

When the voltage of either of the battery cells

exceeds the overcharge protection voltage (V

beyond the overcharge delay time (T

period,

charging is inhibited by the turning-off of the

charge control MOSFET M2. The overcharge

delay time is set by the external capacitor C

Inhibition of charging is immediately released

when the voltage of the overcharged cell becomes

lower than

overcharge release voltage (V

V

Overdischarge Protection

When the voltage of either of the battery cells falls