AIC1782

Dual-Battery Charge Controller

Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan

DS-1782-01 012102

TEL: 886-3-5772500

FAX: 886-3-5772510

www.analog.com.tw

FEATURES

Quick and Easy Testing for Production.

Sequential Charging Control of Two NiMH/NiCd
Battery Packs.

Reliable Sequential Fast Charge Control of Dual
NiMH and/or NiCd Battery Packs, even with a
Fluctuating Charging Current.

Fast Charge Termination by:

T / t ,

0 V

, Safety Timer, Maximum Temperature,

Maximum Voltage.

Safety Timer and

T / t Detection Slope Line-

arly Adjustable.

Battery Voltage Protection Range Selectable.

Mode of Battery Temperature Protection Se-
lectable.

Protection against Battery Voltage and Battery
Temperature Faults.

Selectable LED Display Mode for Battery
Status.

Five Pulsed Trickle Charge Modes.

Discharge-before-Charge Function Available to
Eliminate Memory Effect.

20-pin DIP or SO Packages.

APPLICATIONS

Dual-Battery Fast Chargers for:

Mobile Phones.

Notebook and Laptop Personal Computers.

Portable Power Tools and Toys.

Portable Communication Equipments.

Portable Video & Stereo Equipments.

1.15

1.25

1.35

1.45

1.55

100

Temperature (

C h a r g e C u r r e n t = 6 0 0 m A

C e l l C a p a c i t y = 5 5 0 m A
N i M H B a t t e r y

C e l l V o l t a g e

Cell Voltage (V)

C h a r g e T i m e ( m i n . )

T e m p e r a t u r e

Fig. 1 Battery Charging Characteristics Resulted from

an AIC1782-Controlled Charger with a Fluctuat-
ing Charging Current

DESCRIPTION

The AIC1782 fast charge controller is designed for
intelligent sequential charging of dual NiMH and
NiCd batteries without the risk of malfunction. After
powered on, the AIC1782 charging sequence gives
priority to battery pack A, represented by input
signals of ATS and ABV pins, over battery pack B,
represented by BTS and BBV pin signals. The
AIC1782 automatically switches charging current
to charge the standby battery pack after the bat-
tery pack being charged finishes its charging or
encounters a fault condition.

V (-0.25%) detec-

tion, 0 V

(peak voltage timer) detection, and

T / t detection are the primary methods em-

ployed by the AIC1782 to terminate fast charge.
The fast charge can also be cut off by maximum
battery voltage and maximum battery temperature
detection along with the safety timer to prevent
charging under fault conditions of the charging
system or the battery itself

Both

T / t and

V detection methods have

been proved powerful in terminating fast charging for
NiMH and NiCd batteries. The AIC1782 utilizes the
combination of these two methods to achieve reli-
able decision of ending fast charge and prevent
misaction caused by using

V detection alone

under certain conditions. Fig. 1 shows an example
of charging curve of a battery charged by a fluc-
tuating current from a NiMH battery charger which
uses the AIC1782 controller IC to achieve optimal
charging. The

T / t or

V detection circuitry

may be disabled independently for different applica-
tions, such as system-integrated chargers, charg-
ers with varying charge current, or battery packs
lack of temperature sensing thermistor.

The safety timer period, mode of battery tempera-
ture protection, battery voltage protection range,

AIC1782

pulsed trickle charge duty, and LED display mode
are all adjustable or selectable. Discharge-before-
charge function is included to get rid of memory
effect of NiCd batteries without the risk of overdis-

charging. Test mode is provided for charger
manufactures to dramatically reduce production
test time.

TYPICAL APPLICATION CIRCUIT

R35

D468

R5
20/5W

R32

680

LED5

1M
R36

4.7

100K

C2
0.1

4.7

R8 100K

C4
0.1

1.5K

R37
3.9K

R4
390

D8
1N4148

2.2

C12

Q7
D468

VCC 5V

LED2

LED3

LED4

LED1

1N5820

1N4148

3904

1N4148

1N5821

200

C9
100

C6
100

C11

220

A1012

R28

4.7K

R27

4.7K

R20

680

R19

680

R18

680

R17

680

R14

100K

R13

R34

R25

470

R22

470

0.1/2W

R29
150

R16

R15

R11

R12

R10

R24
2.7K

R21

2.7K

R33

47K

R26

330

R23

330

R30

220

0.1

C10

1nF

BATTERY B

AIC1782

SEL1

MODE

ICOA

LEA2

LEA1

ATS

TMR

SEL3

ADJ

VCC

SEL2

GND

BTS

DIS

LEB1

LEB2

ICOB

BBV

DSW

ABV

(5V)

THERMISTOR

(5V)

AIC1563

VCC

BOOS T

GND

BATTERY A

THERMISTOR

SW1

78L05

Battery Charger for Dual NiMH and NiCd Battery

AIC1782

ORDERING INFORMATION

PACKING TYPE
TR: TAPE & REEL
TB: TUBE

PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE

AIC1782CXXX

Example: AIC1782CSTR

in SO-20 Package & Tape & Reel

Packing Type
(CN is not available in TR packing type)

PIN CONFIGURATION

1 6

1 4

1 5

1 2

1 1

1 3

ABV

BBV

DIS

BTS

VCC

ADJ

SEL3

SEL1

SEL2

LEB1

GND

TMR

DSW

ICOB

LEB2

1 7

2 0

1 9

1 8

MODE

ICOA

LEA2

ATS

LEA1

TOP VIEW

ABSOLUTE MAXIMUM RATINGS

Supply Voltage ............................................................ ... ... ... ... ........................... 5.5V

DC Voltage Applied on any Pin .......................................... ... ... ... ........................ 5.5V

Sink Current of ICOA Pin, LEA1 and LEA2 Pins ................... ... ... ...................... 20mA

Sink Current of ICOB Pin, LEB1 and LEB2 Pins ................... ... ......................... 20mA

Operating Temperature Range ....................................... ... ... ... ................... 0

C~ 70

Storage Temperature Range .............................................. ... ... ... .........

-65

C~ 150

TEST CIRCUIT

ABV

DSW

BBV

ICOB

DIS

LEB2

BTS

LEB1

VCC

GND

ADJ

SEL1

SEL3

SEL2

TMR

MODE

ATS

ICOA

LEA1

LEA2

V2 (3V)

V1 (0.95V)

(5V)

GREEN

ORANGE

AIC1782

YELLOW

Voltage Source

100K

560

Voltage Source

Voltage

Source

560

GREEN

ORANGE

560

RED

560

RED

AIC1782

ELECTRICAL CHARACTERISTICS

=25

C, V

=5V, unless otherwise

specified.)

PARAMETER

TEST CONDITIONS

SYMBOL

MIN.

TYP.

MAX.

UNIT

Supply Voltage

4.5

5.5

Supply Current

1.1

Battery Low

Before Initial Timer

0.11

0.16

0.21

After Initial Timer

(SEL3>3V)

0.63

0.69

0.75

(SEL3<2V)

1.1

1.2

1.3

Battery High

(SEL3>3V)

2.6

2.7

2.8

Voltage Protection Limit

(SEL3<2V)

ABV

BBV

1.9

2.0

2.1

Temperature High

1.35

1.45

1.55

Temperature Sense
Limit

Temperature Low

ATS

BTS

3.5

3.6

3.7

Output Impedance of DIS
Pin

DIS

140

250

LEA1, LEA2, LEB1,
LEB2, ICOA, ICOB pins

Output Impedance

OFF

SEL3 pin

SEL3

5.5

Source Current
Capability

DSW pin

DSW

MODE, SEL1, SEL2
pins

300

Input Impedance

ABV, BBV, ATS, BTS,
ADJ pins

Recommended External
Resistor of TMR pin

TMR

100

1000

V detection level w.r.t.*

Peak Value

-0.25

*: with respected to

AIC1782

TYPICAL PERFORMANCE CHARACTERISTICS

=25

C, R2=100K

=5V, refer to Test Circuit)

4.4

4.6

4.8

5.0

5.2

5.4

1.00

1.06

1.12

1.18

Fig. 2 Supply Current vs. Supply Voltage

Supply Current (mA)

(V)

79.0

79.5

80.0

80.5

81.0

4.4

4.6

4.8

5.0

5.2

5.4

Fig. 3 Safety Timer vs. Supply Volatge

Safety Timer (min.)

(V)

79.0

80.0

81.0

82.0

Fig. 4 Safety Timer vs. Temperature

Safety Timer (min.)

Temperature(

1.02

0.90

1.14

1.26

Fig. 5 Supply Current vs. Temperature

Supply Current (mA)

Temperature (

2.74

2.62

2.66

2.70

Fig. 6 ABV and BBV (High) Limit vs. Temperature

(SEL3>3V)

ABV, BBV (V)

Temperature (

2.02

2.03

1.98

2.00

Fig. 7 ABV and BBV (High) Limit vs. Temperature

(SEL3<2V)

ABV, BBV (V)

Temperature (

AIC1782

TYPICAL PERFORMANCE CHARACTERISTICS

(Continued)

Fig. 8 ABV and BBV (Low) Limit vs. Temperature

(Before Initial Timer)

ABV, BBV (V)

0.158

0.160

0.162

0.163

Temperature (

Fig. 9 Output Impedance vs. Temperature

(LEA's, LEB's, ICO's pins)

Output Impedance(

)

Temperature(

Fig. 10 ABV and BBV (Low ) limits vs. Temperature

(SEL3<2V, After Initial Timer)

ABV, BBV (V)

Temperature (

1.20

1.21

1.22

1.19

Fig. 11 ABV and BBV (Low) limits vs. Temperature

(SEL3>3V, After Initial Timer)

ABV, BBV (V)

Temperature (

0.690

0.695

0.700

0.705

0.710

3.58

3.59

3.60

3.61

3.62

Fig. 12 ATS and BTS (High) Limit vs. Temperature

ATS, BTS (V)

Temperature (

1.42

1.44

1.46

1.48

Fig. 13 ATS and BTS (Low) Limit vs. Temperature

ATS, BTS (V)

Temperature (

AIC1782

BLOCK DIAGRAM

LEB2 LEB1

LEA2

LEA1

ICOB

ICOA

Display

Control

Unit

TMR

Timing

Control Unit

GND VCC

Bandgap

Reference

& Voltage
Regulator

MODE

Selection

SEL3

Battery Voltage
& Temperature

Protection

Setting

SEL2

SEL1

LED Display&

Trickle Charge

Duty Setting

Charge Control

State Machine

CHARGE END

DSW

DIS

BBV

ATS

ADJ

Charge

Control Unit

t Detection

Setting

Battery Temperature

Protection

Battery Voltage

Protection

Discharge

Control Unit

13-bit A/D

Oscillator

BTS

ABV

PIN DESCRIPTIONS

PIN 1: ABV - Divided battery voltage input to

sense the battery voltage of
pack A.

PIN 2: BBV - Divided battery voltage input to

sense the battery voltage of
pack B.

PIN 3: DIS

- Push-pull output, used to control

an external transistor to dis-
charge the battery of pack B.
DIS is active high when function
of discharge is enabled.

PIN 4: BTS - The battery cell temperature of

pack B is represented as a volt-
age input to the AIC1782 at this
pin. The acceptable voltage

range of BTS pin is 0.29V

0.72V

PIN 5: VCC

- Power supply input at 5V

10%.

PIN 6: ADJ

- For adjusting the slope of

T / t . Acceptable voltage

range for this pin is approxi-
mately 0.28V to 3.8V. If volt-
age higher than VCC - 0.3V,
function of

T / t detection is

disabled.

PIN 7: SEL3

- Determining the acceptable

voltage range of ABV and BBV
pins and mode of temperature
protection function.

AIC1782

PIN 8: TMR

- Determining the period of safe-

ty timer with an external resis-
tor connected to GND.

PIN 9: ATS

- The battery cell temperature of

pack A is represented as a
voltage input to the AIC1782 at
this pin. the acceptable voltage
range of ATS is 0.29 V

0.72 V

PIN 10:

LEA1 - Open-drained outputs used to

indicate the charging status of
the battery pack A.

PIN 11:

LEA2 - The same as Pin 10.

PIN 12:

ICOA

- Open-drained output, used to

control the charging current of
the battery pack A.

PIN 13:

MODE - Determining the mode of op-

eration for the AIC1782.

PIN 14:

SEL2

- Tri-level inputs, that jointly con-

trol the LED display mode and
the duty of trickle charge after
the completion of fast charge.

PIN 15:

SEL1

- The same as Pin 14.

PIN 16:

GND

- Power ground.

PIN 17:

LEB1

- Open-drained outputs used to

indicate the charging status of
battery pack B

PIN 18:

LEB2

- The same as Pin 17.

PIN 19:

ICOB

- Open-drained output, used to

control the charging current of
the battery pack B.

PIN 20:

DSW

- Controlling the function of dis-

charge-before-charge of the
battery pack B. (See dis-
charge-before-charge subsec-
tion in application informations).

APPLICATION INFORMATIONS

THE AIC1782 OPERATION

Power-on and Battery Pre-qualifying

The AIC1782 is a sequential charger, initiating a
charge action on either battery pack A or B.
When power is first applied to the AIC1782, all
internal digital circuit of the AIC1782 are reset by
the internal power-on-reset circuitry, the output of
LED`s (depending on the setting of SEL1 and
SEL2 pins) flash 3 times to indicate the initiation
of power-on. If both battery pack A and B are
present when V

is applied to the AIC1782, the

charge action begins with battery pack A if con-
ditions are acceptable.

Condition of battery pack A is examined through
the ATS and ABV pins, while battery pack B is
examined through the BTS and BBV pins. The

acceptable limits of ABV and BBV are deter-
mined by the input voltage of SEL3 pin and the
acceptable temperature sense voltage window for
ATS and BTS are 0.29 V

to 0.72 V

CC.

The AIC1782 controls the initiation of a charge
action and checks for acceptable battery voltage
and temperature prior to fast charging. If the volt-
age of ABV or BBV fail to fall within the prede-
termined acceptable limits, the corresponding
battery pack enters a charging-suspending mode.
If the voltage of ATS or BTS is outside the
0.29V

to 0.72V

window, action to AIC1782 is

determined by the input voltage of SEL3 pin.

Discharge-Before-Charge

AIC1782

The AIC1782 provides the function of discharge-
before-charge to precondition NiCd batteries
which suffer from memory effect. This function
can only be activated for pack B after the pre-
qualification of battery voltage and temperature,
yet before the charge completion is registered for
fast charge cycle of pack B.

To trigger this function, DSW pin has to be bi-
ased to GND over 0.18 second. After discharge
begins, LEB1 and LEB2 pins are both OFF,
ICOB pin is ON, and DIS pin goes high to acti-
vate an external circuit to discharge the battery
pack B until the voltage of BBV pin fall below
0.9V (or 0.69V, depending on the input voltage of
SEL3 pin) or DSW pin is biased to GND for over
0.18 second again. The application circuit is in-
cluded in TYPICAL APPLICATION CIRCUIT.

Fast Charge

After the battery passes fault checks, charge
begins on either of the batteries, the other bat-
tery remains in a waiting state until the first bat-
tery terminates fast charge. The AIC1782 will
automatically switch to fast charge the second
battery. The battery pack A has the priority over
battery pack B only when power is first applied to
the AIC1782. When fast charging begins, the ini-
tial and safety timer of the AIC1782 start count-
ing. Functions of -

V detection, Peak voltage

timer,

T / t detection, and maximum battery

voltage are, however, disabled temporarily until
the initial timer period in the initial stage of a
charge cycle elapses. The initial timer period is
equal to 1/80 of safety timer.

Since the low limit of acceptable ABV or BBV
voltage are only about 0.16V during the initial
timer period, even deeply discharged batteries
can easily qualify to be fast charged subse-
quently.

In the course of fast charge, the AIC1782 con-
stantly monitors the battery voltage and tempera-
ture through ABV (or BBV) and ATS (or BTS)
pins. The fast charge process is registered com-
plete when any one of the following situations is
encountered, which are explained below:

Negative delta voltage (-

V).

Peak voltage timer (0 V

Delta temperature/ delta time (

T / t ).

Maximum charge time.

Maximum battery voltage.

Maximum battery temperature.

V Cutoff

The AIC1782 makes a voltage sampling at ABV
(or BBV) pin every 4 seconds when safety timer
period is set equal to 80 minutes. If a negative
delta voltage of 0.25% compared to its peak val-
ue is detected at ABV (or BBV) pin, the fast
charge cycle is terminated.

V Cutoff

If the battery voltage stays at its peak value or
decreases very slowly for the duration deter-
mined by the peak voltage timer, which is in turn
equal 3.7% of safety timer, the fast charge action
is terminated.

t Cutoff

The

T / t detection of the AIC1782 is per-

formed by sensing the decrease of ATS (or BTS)
pin voltage in a specific timer interval dictated by
the safety timer. The fast charging terminates
when the decrease of ATS (or BTS) pin voltage in
56 seconds exceeds the predetermined value set
by ADJ pin input. This time interval of 56 sec-
onds is based on the assumption that voltage of
ATS (or BTS) pin is sampled once for every 8
seconds, which is also determined by safety
timer.

Functioning of -

V detection and peak voltage

timer (0 V

) can be disabled if the MODE pin is

AIC1782

biased to GND. Functioning of

T / t detection

can be disabled if the voltage of ADJ pin is higher
than V

- 0.3V.

Maximum Safety Timer Cutoff

The maximum fast charge period is determined
by the safety timer, which is set by a resistor
connected from TMR pin to GND. Safety timer,
-

V sampling rate, and

T / t sampling rate will

be longer if the resistor value is larger. When the
value of the resistor is 100K

, the safety timer

period equals 80 minutes. This can be verified by
biasing MODE pin to V

and the measured fre-

quency on DSW pin should be around 32.8 KHz.
After the safety timer period is finished, the fast
charge action is terminated.

Maximum Voltage and Temperature Cutoff

The AIC1782 guards against the maximum limits
for battery voltage and temperature during fast
charging. If either of these limits is exceeded,
fast charge action is terminated.

Trickle Charge

There are five different selectable duty cycles for
trickle charge after the fast charge to prevent the
loss of charge due to battery self-discharging.
The setting of SEL1 and SEL2 pins controls the
duty cycle

This function can only be activated

on the following three situation:

Battery pack A is charge full and battery

pack B is abnormal.

Battery pack B is charge full and battery

pack A is abnormal.

Battery pack A and B are both charge full.

DESIGN GUIDE

ABV/BBV Range and Temperature Protec-
tion

The acceptable battery voltage range of ABV and
BBV pins and mode of temperature protection

function is determined by the voltage of SEL3 pin,
shown as the following:

(a) SEL3 > V

- 0.3V

Acceptable ABV/BBV Range:

Before initial timer: 0.16V~2.7V
After initial timer: 0.69V~2.7V

Temperature Protection Mode:

Entering charge-suspending mode when tem-
perature is either too low or too high, same as
abnormal battery voltage. Latch for charge-
suspending function is provided for high tempera-
ture protection, but not for low temperature pro-
tection.

(b) V

- 1.4V> SEL3 >

- 0.4V

Acceptable ABV/BBV Range:

Before initial timer: 0.16V~2.7V
After initial timer: 0.69V~2.7V

Temperature Protection Mode:

If temperature is too high, battery charging
is regarded as completed. If temperature is
too low, function of

T / t detection is dis-

abled, just as thermistor is not existing.

(c)

- 0.4V>SEL3 >1.4V

Acceptable ABV/BBV Range:

Before initial timer: 0.16V~2 V
After initial timer:1.2V~2V

Temperature Protection Mode:

Entering charge-suspending mode when
temperature is either too low or too high,
same as abnormal battery voltage. Latch for
charge-suspending function is provided for
high temperature protection, but not for low
temperature protection.

(d) 0.3V> SEL3

Acceptable ABV/BBV Range:

Before initial timer: 0.16V~2 V
After initial timer:1.2V~2V

AIC1782

Temperature Protection Mode:

If temperature is too high, battery charging
is regarded as completed. If temperature is
too low, function of

T / t detection is dis-

abled, just as thermistor is not existing.

Battery Voltage Measurement

The AIC1782 measures the battery voltage
through ABV and BBV pins, which is connected
to battery positive terminal through a resistor-
divider network, as shown in Fig. 14. The ac-
ceptable limit of divided battery voltage is deter-
mined by the input voltage of SEL3 pin.

BAT

4.7

100K

0.1

AIC1782

ABV/BBV

Fig. 14 Battery Voltage Divider

For SEL3 > (VCC/2) + 0.4V, the suggested di-
vider resistances of RA and RB for the corre-
sponding number of battery cells are as below:

TABLE 1

BATTERY

CELLS

RA/RB

RA (K

)

RB (K

)

2~4

240

120

3~6

3.3

300

4~8

4.9

300

5~10

6.4

300

6~12

7.8

310

8~16

10.8

390

For SEL3 < (V

/2) -0.4V, the suggested divider

resistances of RA and RB for the corresponding
number of battery cells are as below:

TABLE 2

BATTERY

CELLS

RA/RB

RA(K

)

RB (K

)

240

120

240

300

360

390

410

Battery Temperature Measurement

The AIC1782 employs a negative temperature
coefficient (NTC) thermistor to measure the bat-
tery

temperature. The thermistor is inherently

nonlinear with respect to temperature. To reduce
the effect of nonlinearity, a resistor-divider net-
work in parallel with the thermistor is recom-
mended. A typical application circuit is shown in
Fig. 15.

AIC1782

BAT

0.1

VCC

GND

Thermistor

ATS/BTS

AIC1782

Fig. 15

Battery Temperature Sen-

se Circuit with a Negative Tempera-
ture Coefficient (NTC) Thermistor

The calculation for Rx and Ry in the circuit is as
following.

0.29 Vcc

Ry / /R

Rx (Ry / / R

)

Vcc

= The resistance of thermistor at upper limit

of temperature protection.

Vcc

)

(Ry//

Ry//R

Vcc

0.72

= The resistance of thermistor at lower limit

of temperature protection.

Substitution and rearranging the equations yield

Rx= 2.061

Ry =

6.3R

5.3

If temperature characteristic of the thermistor is
like that of SEMITEC 103AT-2, the resistance
of Rx and Ry is tabulated for different TL and
TH as below.

(note: TL is lower temperature limit and TH is up-
per temperature limit.)

TABLE 3 Values of Rx and Ry at TL = 0

TH (

Rx(K

)

Ry (K

)

10.1

551.1

9.7

300.7

9.4

204.8

9.0

153.9

8.7

122.8

8.4

101.8

8.1

86.5

7.8

75.0

7.5

66.0

7.2

58.7

7.0

52.8

6.8

47.8

6.5

43.6

6.3

39.9

6.1

36.8

5.9

34.0

5.7

31.6

5.5

29.5

5.3

27.5

5.2

25.8

5.0

24.3

TABLE 4 Values of Rx and Ry at TL = -10

TH (

Rx (K

)

Ry (K

)

11.4

95.6

11.0

85.0

10.6

76.2

10.2

68.9

9.8

62.8

9.5

57.5

9.1

52.9

8.8

48.8

8.5

45.3

8.2

42.1

7.9

39.4

7.6

36.8

7.4

34.6

7.1

32.5

6.9

30.7

6.7

29.0

6.4

27.4

6.2

26.0

6.0

24.6

5.8

23.4

5.6

22.2

AIC1782

Setting the ADJ Pin Voltage

The slope of

T / t detection is determined by

ADJ pin voltage of the AIC1782.

The calculation of ADJ pin voltage is shown in
the following procedure followed by an example.

Procedure

(a) First, determine the temperature protection

limits TH and TL. Then, substitute TH & TL
into the following equation:

0.72V

0.29V

TH TL

0.43V

TH TL

BASE

(b) Determine the safety timer to obtain the val-

ue of

BASE

(min

Timer

Safety

(min

56(sec.)

(sec.)

BASE

T / t at

which temperature rises y

C in x seconds

and fast charge is subsequently cut off.

(d) Calculate the value of V

ADJ

T S

BASE

Example

(a) Let TH=50

C, TL=0

C, V

=5V. We have

0.043V/

0.43

BASE

which means that V

decreases 43mV as

temperature rises 1

(b) If safety timer is equal to 80 minutes,

BASE

is then 56 seconds.

temperature rises 1

C in 60 seconds, then

T / t =

0.0166

(d) V

ADJ

=25 x 0.043 x 0.0166 x 56 = 1(V)

If the temperature range is from 0

C to 50

the voltage of V

ADJ

under different setting

conditions should be set as tabulated below.

TABLE 5 ADJ Pin Voltage (TL=0

C, TH=50

T / t

S.T.

0.75

(

C/min.)

1.0

(

C/min.)

1.25

(

C/min.)

40 min. (2C)

0.37

0.5

0.63

80 min. (1C)

0.75

1.0

1.25

120 min. (0.67C)

1.12

1.5

1.87

160 min. (0.5C)

1.5

2.0

2.5

200 min. (0.4C)

1.87

2.5

3.12

240 min. (0.33C)

2.25

3.0

3.75

A similar table for temperature range from 0

C to

C is as below.

TABLE 6 ADJ Pin Voltage (TL=0

C, TH=60

T / t

S.T.

0.75

(

C/min.)

1.0

(

C/min.)

1.25

(

C/min.)

40 min. (2C)

0.31

0.42

0.52

80 min. (1C)

0.62

0.84

1.05

120 min. (0.67C)

0.94

1.25

1.56

160 min. (0.5C)

1.25

1.67

2.08

200 min. (0.4C)

1.56

2.08

2.60

240 min. (0.33C)

1.87

2.5

3.12

Setting the Period of Safety Timer
The AIC1782 provides a method for linearly ad-
justing the period of safety timer with an external
resistor connected from TMR pin to GND. The
relation between safety timer length and the ex-
ternal resistor (R

TMR

) is shown in Fig. 16. The ta-

ble following shows the resistor values for some
of the commonly chosen safety timer periods.

AIC1782

Also shown in the table is their corresponding
oscillator frequencies.

100

200

300

400

500

200

400

600

800

TMR

)

Safety Timer (min.)

Fig. 16 Safety Timer vs R

TMR

TABLE 7

TMR

)

Osc.Freq.

(KHz)

Safety timer

(min.)

262.4

131.2

65.6

43.7

100

32.8

152

21.9

120

206

16.4

160

314

10.9

240

491

7.3

360

667

5.5

480

Selecting Mode of Operation
The AIC1782 provides three modes of operation:
normal, test, and AC mode, determined by the
setting of MODE pin according to TABLE 8. The
AIC1782 will operate normally when the MODE
pin is left floating (a 0.1

F capacitor is recom-

mended to be tied to MODE pin if the charge cir-
cuit works in a noisy environment). When the
MODE pin is biased to GND, the function of

detection is disabled. When the MODE pin

is biased to V

, the AIC1782 enters the test

mode. The test mode can be used to signifi-
cantly reduce production test time. For relevant
informations please contact AIC directly.

TABLE 8 The Operating Mode of AIC1782

MODE pin

Mode

Function

Test

Safety timer period
scaled down to 1/32....
etc.

Floating

Normal Normal operation

GND

V detection disabled

The Mode of LED Display and Trickle Charge
The AIC1782 provides two LED display modes
and five pulsed trickle charge modes. The modes
of LED display and trickle charge are determined
by the tri-level inputs, SEL1 and SEL2 pins, as
in the TABLE 9.

TABLE 9 Mode of LED Display and Trickle
Charge

SEL1

SEL2

Trickle Charge

Duty

LED

Display

Mode

Floating
GND

N/A

1/32
1/64

Type 1
Type 1
Type 1

Floating

Floating
GND

1/128
1/256

N/A

Type 1
Type 1
Type 2

GND

Floating
GND

1/32
1/64

1/128

Type 2
Type 2
Type 2

Displaying the Battery Charging Status

The AIC1782 provides four open-drained outputs, in
which LEA1 and LEA2 are used to indicate the
battery charging status of pack A, yet LEB1 and
LEB2 are used to indicate battery charging status
of pack B. Refer to the table of LED display mode
(TABLE 6), depending on the setting of SEL1 and
SEL2 pins, the outputs of LEA1, LEA2, LEB1, and
LEB2 pins are shown in the following table:
TYPE 1

Power

Wait

Charge

Full

Abnormal

LEA1/

1HZ

OFF

AIC1782

LEB1

LEA2/

LEB2

OFF

TYPE 2

Power

Wait

Charge

Full

Abnormal

LEA1/

LEB1

1HZ

OFF

4HZ

LEA2/

LEB2

1HZ

4HZ

OFF

Charging Current Control

As shown in the typical application circuit, the
AIC1782 offers two open-drained output pins, ICOA
and ICOB pins, to control the charging current of
battery pack A and pack B. When fast charge is
completed, the AIC1782 enters the trickle charge
mode. In trickle charge mode, the ICOA or ICOB
pins output switch with predetermined duty cycle.
Refer to the table of trickle charge mode (TABLE
6), the duty cycle is determined by the setting of
SEL1 and SEL2 pins. The following table summa-
rizes how ICOA and ICOB pins correspond to vari-
ous charging states.

Power

Wait

Fast

Charging

Charge

Completed

Fault

Conditions

ICOA/

ICOB

OFF

See pin 14

& 15

Test Mode

Fig. 17 shows the timing diagram for externally
controlled ADJ, ABV, BBV, ATS, BTS, SEL1 and
SEL2 pin voltages of a recommended AIC1782
test scheme, utilizing TEST mode function. Output
waveforms of LEA1, LEA2, LEB1, LEB2, ICOA
and ICOB of a properly functioning AIC1782 are
also shown in the figure. For detailed information
please consult with AIC staffs directly.

AIC1782

TIMING DIAGRAM

SAFETY TIMER TEST

t TEST

PEAK TIMER TEST

Power

Init.

GND
GND

GND

Floating

VCC

Floating

Floating
Floating

(-0.15%)

(-2.5%)

OFF

2mV
Step/100mS

2mV

Step/100mS

1.993V
(-0.35%)

1.95V

1.96V

1.9V

1.997V

1.5V

(-2.15%)

1.85V

1.12V

OFF

3.2KHz

OFF

VCC, SEL3, MODE=5V, (DSW FREQ.=820KHz, 25 TIMES of 32.8K)

V DISALBE TEST

V TEST

1.32

0.4

0.12

0.74

0.12

0.02

0.32

0.97

0.32

0.26

0.24

0.1

0.5

0.12

5.89

5.99

6.01

4.57

4.17

3.93

3.43

2.46

2.14

1.26

2.02

1.17

1.38

0.26

0.14

Floating

GND

Floating
Floating

OFF

<2.1V

0.4

Delay 0.3

0.74

0.12

0.26

0.24

0.5

8.91

8.51

8.27

7.77

7.47

7.21

(A):ICOA
(B):ICOB

(A):ABV
(B):BBV

ADJ

(A):LEA2
(B):LEB2

(A):LEA1
(B):LEB1

(A):ATS
(B):BTS

TIME (A)

(SEC.)

STAGE

SEL1
SEL2

TIME (B)

(SEC.)

STAGE

6.11

6.37

6.25

0.14

0.1

6.01

0.1

Fig. 17 Timing Diagram of AIC1782 in Test Mode

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