8181

LOW-DROPOUT,

5 V REGULATOR

DISCONTINUED PRODUCT

— FOR REFERENCE ONL

Y

8181

LOW-DROPOUT, 5 V REGULATOR

— HIGH EFFICIENCY

Especially suited for hand-held, portable, battery-operated equip-

ment such as cellular telephones, the A8181SLB low dropout voltage
regulator provides high efficiency for maximum battery life in a mini-
mum package size. Equally applicable to camcorders and portable
computers, the device provides a fixed 5 V regulated continuous output
at almost 200 mA of load current under worst-case conditions. Under
normal operating conditions, output currents over 500 mA are
permitted.

A MOSFET pass element delivers high output current with an

input-output differential of less than 300 mV. For high efficiency, the
low dropout voltage allows a longer battery discharge before output
voltage regulation is lost. A low quiescent current, even during high
load conditions, makes the device ideal for standby power systems.
High regulator accuracy and excellent temperature characteristics are
provided by a bandgap reference. An enable input gives the designer
complete control over sequential power-up or emergency shutdown.

This device is supplied in a 16-lead wide-body, small-outline

plastic power package (SOIC) for surface-mount applications. The
copper batwing provides for maximum package power dissipation in
the smallest possible construction. The A8181SLB is rated for opera-
tion over a temperature range of -20

°

C to +85

°

C.

FEATURES AND BENEFITS

■

High Efficiency Provides Extended Battery Life

■

Less Than 300 mV Dropout Voltage

■

Low Quiescent Current

■

>200 mA Output Current

■

LSTTL-Compatible ON/OFF Control

For Sequential Power-up or Emergency Shutdown

■

Internal Thermal Protection

■

SOIC Surface-Mount Package

Always order by complete part number:

A8181SLB

.

ABSOLUTE MAXIMUM RATINGS

at T

A

= +25

°

C

Input Voltage, V

I

................................... 10 V

Output Current, I

O

(40% duty cycle) ............................ 1 A*
(75% duty cycle) ..................... 500 mA*
(continuous) ............................ 370 mA*

Operating Temperature Range,

T

A

................................. -20

°

C to +85

°

C

Junction Temperature, T

J

.............. +150

°

C†

Storage Temperature Range,

T

S

............................... -40

°

C to +150

°

C

* Output current rating is limited by input voltage,
duty cycle, and ambient temperature. Under any
set of conditions, do not exceed a junction
temperature of +150

°

C. See next page.

† Fault conditions that produce excessive
junction temperature will activate device thermal
shutdown circuitry. These conditions can be
tolerated but should be avoided.

Data Sheet

27468*

1

2

3

4

5

12

13

14

15

16

GROUND

Dwg. PS-018

6

7

10

11

8

9

GROUND

GROUND

GROUND

NC

NC

NC

OUT

IN

IN

ENABLE

NC

NC

NC

NC

OUT

VR

5 V

8181

LOW-DROPOUT,

5 V REGULATOR

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

Maximum Allowable Output Current in Milliamperes with V

I

= 10 V, T

J

= 150

°

C*

dc (Duty Cycle)

T

A

100%

90%

80%

70%

60%

50%

40%

30%

20%

25

°

C

370

415

465

530

620

745

930

1000

1000

50

°

C

295

330

370

425

495

595

745

995

1000

70

°

C

235

265

295

340

395

475

595

795

1000

85

°

C

190

215

240

275

320

385

485

645

970

* I

O

= (T

J

- T

A

)/([V

I

- V

O

] R

θ

JA

• dc) = (150 - T

A

)/(5 • 67 • dc)

Output current rating can be increased (to 1 A maximum) by heat sinking or reducing the input voltage. With an infinite heat sink, R

-JA

= R

-JT

=

6

°

C/W. Conditions that produce excessive junction temperature will activate device thermal shutdown circuitry. These conditions can be tolerated

but should be avoided.

FUNCTIONAL BLOCK DIAGRAM

12-13

Dwg. FS-012

BIAS

DRIVE

ENABLE

THERMAL

PROTECT.

BANDGAP

REF.

ERROR

AMP

4-5

IN

ENABLE

OUT

IN

OUT

7

8

15

16

6

MAXIMUM ALLOWABLE OUTPUT CURRENT with device mounted on 2.24" x 2.24"

(56.9 mm x 56.9 mm) solder-coated copper-clad board in still air.

W
Copyright © 1992, 1995 Allegro MicroSystems, Inc.

8181

LOW-DROPOUT,

5 V REGULATOR

ELECTRICAL CHARACTERISTICS at T

A

+25

°

C (unless otherwise noted).

Limits

Characteristic

Symbol

Test Conditions

Min.

Typ.

Max.

Units

Output Voltage

V

O

T

A

= 25

°

C, 5.5 V

≤

V

I

≤

10 V,

4.90

5.00

5.10

V

0 mA

≤

I

O

≤

500 mA†

T

A

= 85

°

C, 5.5 V

≤

V

I

≤

10 V,

4.85

—

5.15

V

0 mA

≤

I

O

≤

500 mA*†

Output Volt. Temp. Coeff.

α

VO

I

O

= 0

—

±

100

—

µ

V/

°

C

Line Regulation

∆

V

O(

∆

VI)

5.5 V

≤

V

I

≤

10 V, Output open

—

10

30

mV

Load Regulation

∆

V

O(

∆

IO)

0 mA

≤

I

O

≤

500 mA†, V

I

= 6 V

—

40

100

mV

Dropout Voltage

V

I

min - V

O

I

O

= 500 mA†

—

—

300

mV

Quiescent Current

I

Q

V

I

= 10 V, I

O

= 500 mA†

—

87

120

µ

A

V

I

= 10 V, Output open

—

86

120

µ

A

I

Q(off)

V

I

= 10 V, Output open, V

E

= 0.4 V

—

—

20

µ

A

ENABLE Input Voltage

V

EH

Output ON, V

I

= 10 V

2.4

—

—

V

V

EL

Output OFF, V

I

= 10 V

—

—

0.4

V

ENABLE Input Current

I

E

V

E

= V

I

= 10 V

—

—

±

0.1

µ

A

Thermal Shutdown Temp.

T

J

—

165

—

°

C

Thermal Resistance

R

θ

JA

Mounted on 2.24" x 2.24" solder-coated

—

67

—

°

C/W

copper-clad board in still air

R

θ

JT

—

6.0

—

°

C/W

Typical values are given for circuit design information only.

* This parameter is tested to a lot sample plan only.

† Pulse test (<20 ms).

(GND terminal current)

8181

LOW-DROPOUT,

5 V REGULATOR

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

0

OUTPUT CURRENT, I

O

in mA

Dwg. GP-039-1

100

200

400

500

300

T = 25

°

C

A

5.04

5.00

5.02

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

4.96

4.94

5.06

4.92

V = 7 V

I

V = 6 V

I

V = 8 V

I

V = 10 V

I

V = 5.5 V

I

5.0

Dwg. GP-040-1

6.0

7.0

9.0

10

8.0

T = 25

°

C

A

5.04

5.00

5.02

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

4.96

4.94

5.06

4.92

I = 0 mA

O

I = 500 mA

O

INPUT VOLTAGE, V

I

in VOLTS

100 mA INTERVALS

CAUTION:

Maximum allowable duty cycle will be significantly less than 100% at high temperatures, at high input voltages, or at high output
currents. See Maximum Allowable Output Current table.

TYPICAL CHARACTERISTICS

5.0

Dwg. GP-040

6.0

7.0

9.0

10

8.0

T = -20

°

C

A

5.04

5.00

5.02

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

4.96

4.94

5.06

4.92

I = 0 mA

O

INPUT VOLTAGE, V

I

in VOLTS

100 mA INTERVALS

I = 500 mA

O

0

OUTPUT CURRENT, I

O

in mA

Dwg. GP-039

100

200

400

500

300

V = 7 V

I

V = 6 V

I

V = 8 V

I

V = 10 V

I

T = -20

°

C

A

5.04

5.00

5.02

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

4.96

4.94

5.06

4.92

V = 5.5 V

I

LOAD REGULATION

LINE REGULATION

8181

LOW-DROPOUT,

5 V REGULATOR

0

OUTPUT CURRENT, I

O

in mA

Dwg. GP-041

100

200

400

500

300

T = -20

°

C

T = 25

°

C

T = 85

°

C

A

A

A

0.3

0.4

0.2

DROPOUT VOLTAGE in VOLTS

0.1

0.5

0

DROPOUT VOLTAGE

OUTPUT VOLTAGE vs TEMP.

CAUTION:

Maximum allowable duty cycle will be significantly less than 100% at high temperatures, at high input voltages, or at high output
currents. See Maximum Allowable Output Current table.

TYPICAL CHARACTERISTICS (cont’d)

5.0

Dwg. GP-040-2

6.0

7.0

9.0

10

8.0

T = 85

°

C

A

5.04

5.00

5.02

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

4.96

4.94

5.06

4.92

I = 0 mA

O

I = 500 mA

O

INPUT VOLTAGE, V

I

in VOLTS

100 mA INTERVALS

0

OUTPUT CURRENT, I

O

in mA

Dwg. GP-039-2

100

200

400

500

300

T = 85

°

C

A

5.04

5.00

5.02

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

4.96

4.94

5.06

4.92

V = 7 V

I

V = 6 V

I

V = 8 V

I

V = 10 V

I

V = 5.5 V

I

LOAD REGULATION

LINE REGULATION

-50

AMBIENT TEMPERATURE, T

A

in

°

C

Dwg. GP-036

5.01

4.99

0

+50

5.00

+100

4.98

OUTPUT VOLTAGE, V

O

in VOLTS

V = 6 V

I = 0 mA

I

O

8181

LOW-DROPOUT,

5 V REGULATOR

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

4.0

Dwg. GP-042

6.0

7.0

9.0

10

8.0

INPUT VOLTAGE, V

I

in VOLTS

20

90

70

60

50

80

QUIESCENT (GROUND TERMINAL) CURRENT in

µ

A

40

30

5.0

3.0

T = 25

°

C

A

I = 0 mA

O

TRANSIENT PERFORMANCE

Dwg. WP-018

VO

IO

500 mA

20 mA

5.5 V

5.0 V

4.5 V

<100

µ

s

<500

µ

s

V

I

= 5.5 V to 10 V, T

A

= -20

°

C to +85

°

C, C

O

= 4.7

µ

F

CAUTION:

Maximum allowable duty cycle will be significantly less than 100% at high temperatures, at high input voltages, or at high output
currents. See Maximum Allowable Output Current table.

TYPICAL CHARACTERISTICS (cont’d)

0

80

OUTPUT CURRENT, I

O

in mA

Dwg. GP-038

87

85

84

83

100

200

400

500

86

300

QUIESCENT (GROUND TERMINAL) CURRENT in

µ

A

82

81

V = 7 V

V = 6 V

V = 8 V

V = 9 V

V = 10 V

I

I

I

I

I

T = 25

°

C

A

-50

AMBIENT TEMPERATURE, T

A

in

°

C

Dwg. GP-037

80

0

+50

79

+100

78

V = 6 V

I = 0 mA

I

O

QUIESCENT (GROUND TERMINAL) CURRENT in

µ

A

81

QUIESCENT (GROUND TERMINAL) CURRENT

8181

LOW-DROPOUT,

5 V REGULATOR

Dimensions in Inches

(Based on 1 mm = 0.3937”)

NOTES: 1. Webbed lead frames. Leads 4, 5, 12, and 13 are internally one piece.

2. Lead spring tolerance is non-cumulative.

3. Exact body and lead configuration at vendor’s option within limits shown.

Dimensions in Millimeters

0

°

TO

8

°

1

2

3

0.2992
0.2914

0.4133
0.3977

0.419
0.394

0.020
0.013

0.0926
0.1043

0.0040

MIN.

0.0125
0.0091

0.050
0.016

Dwg. MA-008-17A in

0.050

BSC

16

9

0

°

TO

8

°

9

1

16

2

3

7.60
7.40

10.50
10.10

10.65
10.00

0.51
0.33

2.65
2.35

0.10

MIN.

0.32
0.23

1.27
0.40

Dwg. MA-008-17A mm

1.27

BSC

8181

LOW-DROPOUT,

5 V REGULATOR

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from

the detail specifications as may be required to permit improvements in the design of its products.
Components made under military approvals will be in accordance with the approval requirements.

The information included herein is believed to be accurate and reliable. However, Allegro

MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other
rights of third parties which may result from its use.