AIC AIC1781CS, AIC1781 Datasheet

AIC1781

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Battery Charge Controller

FEATURES



 Fast Charge Control of NiMH/NiCd Batteries,

even with a Fluctuating Charging Current.

∆∆T

 Fast Charge Termination by:

0V∆

, Safety Timer, Maximum Temperature,

t, −∆V

Maximum Voltage.

∆∆T

 Linearly Adjustable

t

Detection Slope and

Safety Timer.

 Adjustable Peak Voltage Timer for
 Battery Voltage Protection Range Selectable.
 Selectable Battery Temperature Protection

0V∆

.

Mode.

 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 for

Eliminating Memory Effect.

 Quick and Easy Testing for Production.
 16-pin DIP or SO Packages.

APPLICATIONS



Battery Fast Chargers for:

 Mobile Phones.
 Notebook and Laptop Personal Computers.
 Portable Power Tools and Toys.
 Portable Communication Equipments.
 Portable Video & Stereo Equipments.

1.55

Charge Current = 600 mA
Cell Capacit y = 550 mA
NiMH Battery

1.45

V
e

1.35

Cell Volta

1.25

1.15

Cell Voltage

Temperature

0 102030405060

Charge Time (min.)

100

80

60

40

Temperature (°C)

20

Fig. 1 Battery Charging Characteristics Resulting

from an AIC1781-Controlled Charger with a
Fluctuating Charging Current

DESCRIPTION



The AIC1781 fast charge controller IC is designed
for intelligent charging of NiMH or NiCd batteries

,

without the risk of overcharge.

∆∆T

0V∆

detection (peak voltage timer)

t

detection are the primary methods

(-0.25%),
and

−∆V

detection

employed by the AIC1781 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.

∆∆T

Both

t

and

−∆V

detection methods have
been proved powerful in terminating fast charging
for NiMH and NiCd batteries. The AIC1781 utilizes
the combination of these two methods to achieve
reliable 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
fluctuating current from a NiMH battery charger
which uses the AIC1781 controller IC to achieve
optimal charging. This technique, in cooperating
with the

0V∆

detection (peak voltage timer), is
particularly suitable for NiMH batteries, whose
voltage drop is hardly significant yet temperature
rises rapidly. The

t

or

−∆V

detection

∆∆T

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

The safety timer period, mode of battery
temperature protection, battery voltage protection
range, pulsed trickle charge duty, and LED display
mode are all adjustable or selectable. Discharge­before-charge function is included to get rid of
memory effect of NiCd batteries without the risk of
overdischarging. Test mode is provided for charger
manufactures to dramatically reduce production
test time.

Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC www.analog.com.tw

DS-1781-00 TEL: [phone] FAX: [phone]

1

TYPICAL APPLICATION CIRCUIT

µ

A

A

A

(

)

A



AIC1781

VIN

R4

390K

C1

1000P

D1

IN4148

C2

1µF

U1

1

DC

DE

CF

GND

+

C12

1uF

AIC1563

1

BOOST

IS

VCC

FB

U3 7805

VIN

2

3

4

2

8

7

6

5

VOUT

GND

R1

1K

R5 120/0.5W

D3

IN4148

R6

0.3/1W

+

C3

220µF

3

L1

220µH

+

C13

10µF

Battery Charge Circuit for Fluctuating Charging Current Application

ORDERING INFORMATION



IC1781XX

+

C4
220µF

D4

1N5819

BAT1

BATTERY

D2 IN4148

C5

.1µF

0

R9
240K

R8

120K

R7

THERMIS TOR

ORDER NUMBER

RY1

100K

+

C9

4.7µF

2N3904

RX1

100K

C6

0.1

470K

Q2

SW PB

AIC1781

DSW

ICON

LED2

LED1

GND

SEL1

SEL2

MODE

SW1

LED3

LED2

R12

GREEN

100K

16

15

14

13

12

11

10

9

R16

680

RED

R17

680

R3

R2

C10

47nF

+

C11

100µF

270

Q1

2N3904

C8

0.1µF

LED1

YELLOW

R15

680

R14

200K

R18

50K

R11

100K

1

PEAK

2

VBT

3

DIS

4

VTS

5

VCC

6

ADJ

7

SEL3

8

TMR

20/5W

R10
100K

C7

0.1µF

F

R13

PIN CONFIGURATION

PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE

IC1781CN

(PLASTIC DIP)

PEAK

VBT

DIS

TEMPERATURE RANGE
C= 0°C~70°C

IC1781CS

PLASTIC SO

VTS

VCC

DJ

SEL3

TMR

ABSOLUTE MAXIMUM RATINGS



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

DC Voltage Applied on any pin ......................……………...................................... 5.5V

Sink current of ICON pin, LED1 and LED2 pin .......................……….................. 20mA

Operating Temperature Range .....................................…………….............. 0°C~ 70°C

Storage Temperature Range .............................................…………...... -65°C~ 150°C

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

DSW

ICON

LED2

LED1

GND

SEL1

SEL2

MODE

2

TEST CIRCUIT

A



V

CC

VOLTAGE

SOURCE

-+

YELLOW

R1

560

-+

VOLTAGE SOURCE

VCC (5V)

V

V1 (0.95V)

CC

PEAK DSW

VBT ICON

DIS LED2

VTS LED1

AIC1781

VCC GND

DJ SEL1

R3

560

R4

560

R5

560

ORANGE

GREEN

RED

V

CC

AIC1781

V

CC

V2 (3V)

100K

ELECTRICAL CHARACTERISTICS (Ta=25°



SEL3 SEL2

TMR MODE

R2

PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT

Supply Voltage V

Supply Current I

Voltage Protection Limit

Battery Low

During 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 1.30

Battery High

(SEL3>3V) 2.6 2.7 2.80
(SEL3<2V)

V

CC

V

CC

°C, VCC=5V, unless otherwise specified.)

°°

CC

CC

V

BT

4.5 5.0 5.5 V

1.1 mA

V

1.9 2.0 2.10

3

AIC1781

ELECTRICAL CHARACTERISTICS (Ta=25°



PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT

Temperature High 1.35 1.45 1.55

Temperature Sense Limit

Temperature Low

Output impedance of DIS Pin Z

LED1, LED2, ICON Pins

Output Impedance

ON
OFF 1

Source Current
Capability

SEL3 pin
DSW pin

MODE, PEAK, SEL1,

Input Impedance

SEL2 pins 300 KΩ

VBT, VTS, ADJ pins 1 MΩ

Recommended
External Resistor of TMR pin

°C, VCC=5V, unless otherwise specified.)

°°

V

TS

DIS

3.5 3.6 3.70

140 250 Ω

25 50 Ω

I

SEL3

I

DSW

R

TMR

2 100 1000 KΩ

5.5
16

V

MΩ

µA

-∆V Detection Level w.r.t.*
Peak Value

TYPICAL PERFORMANCE CHARACTERISTICS (Ta=25°



V

=5V, refer to Test Circuit)

CC

1.21

1.18

1.12

1.06

Supply Current (mA)

1.00

4.4 4.6 4.8 5.0 5.2 5.4

Supply Current vs Supply Voltage

VCC (V)

81.0

80.5

80.0

Safety Timer (min.)

79.5

79.0

4.4 4. 6 4.8 5. 0 5.2 5.4

Safety Timer vs Supply Volatge

-0.25 %

°C, R2=100KΩΩΩΩ,

°°

VCC (V)

4

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)



AIC1781

LED Flashing Frequency vs Supply Voltage

4.8

4.6

4.4

4.2

Frequency (Hz)

4.0

3.8

4.44.64.85.05.25.4

V

CC

(V)

Safety Timer vs Temperature

82.0

81.0

80.0

Safety Timer (min.)

Supply Current vs Temperature

1.26

1.14

1.02

Supply Curr ent (mA)

0.9

020406080

Temperature (°C)

LED Flashing Frequency vs Temperature

5.0

4.6

4.2

Fre quenc y ( Hz)

3.8

79.0

0

20 40 60 80

Temperature(°C)

VBT (high) Limit vs Temperature

(SEL3>3V)

2.74

2.70

(V)

BT

V

2.66

2.62
0 20406080

Temperature (°C)

3.4
020406080

Temperature(°C)

VBT (high) Limit vs Temperature

(SEL3<2V)

2.03

2.01

(V)

BT

V

1.99

1.98

0

20 40 60 80

Temperature (°C)

5

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(

)



AIC1781

VBT (low) Limit vs Temperature (During Initial Timer)

0.163

0.162

0.161

(V)

BT

V

0.160

0.159

0.158

0 20406080

Temperature (°C)

VTS (high) Limit vs Temperature

3.62

3.61

(V)

TS

3.60

V

3.59

Output Impedance vs Temperature

(LED1,LED2,ICON pins)

29

)

Ω

27

25

Output Impedance(

23

020406080

Temperature (°C)

VTS (low) Limit vs Temperature

1.48

1.46

(V)

TS

V

1.44

3.58
0 20406080

Temperature (°C)

V

Limits vs Temperature

BT(LOW)

(SEL3>3V, After Initial Timer)

0.700

0.695

(V)

BT

V

0.690

0.685

020

40

Temperature (°C)

60 80

1.42

1.24

1.22

0

20 40 60 80

Temperature (°C)

Limits vs Temperature

V

BT(LOW)

(SEL3<3V, After Initial Timer)

V

BT

V

1.20

1.18
0 20406080

Temperature (°C)

6