NSC LM1086CT-5.0, LM1086CT-3.3, LM1086CT-2.85, LM1086CSX-5.0, LM1086CSX-2.85 Datasheet

LM1086

1.5A Low Dropout Positive Regulators

1.5A Low Dropout Positive Regulators

August 1999

General Description

The LM1086 is a series of low dropout positive voltage regu­lators with a maximum dropout of 1.5V at 1.5A of load cur­rent. It has the same pin-out asNationalSemiconductor’sin­dustry standard LM317.

The LM1086 is available in an adjustable version, which can
set the output voltage with only two external resistors. It is
also available in three fixed voltages: 2.85V, 3.3V and 5.0V.
The fixed versions integrate the adjust resistors.

The LM1086 circuit includes a zenertrimmedbandgaprefer­ence, current limiting and thermal shutdown.

The LM1086 series is available inTO-220andTO-263 pack­ages. D-Pak is available upon special request; contact the
National Semiconductor sales representative in your area.

Connection Diagrams

TO-220

DS100948-2

Top View

Features

n Available in 2.85V, 3.3V, 5V andAdjustable Versions
n Current Limiting and Thermal Protection
n Output Current 1.5A
n Line Regulation 0.015%(typical)
n Load Regulation 0.1%(typical)

Applications

n SCSI-2 Active Terminator
n High Efficiency Linear Regulators
n Battery Charger
n Post Regulation for Switching Supplies
n Constant Current Regulator
n Microprocessor Supply

TO-263

DS100948-4

Top View

Note: D-Pak package also available. Contact National Semiconductor sales

representative in your area.

Basic Functional Diagram, Adjustable Version

DS100948-65

© 1999 National Semiconductor Corporation DS100948 www.national.com

Ordering Information

Package Temperature Range Part Number Transport Media NSC Drawing

3-lead TO-263 −40˚C to +125˚C LM1086IS-ADJ Rails

LM1086ISX-ADJ Tape and Reel

LM1086IS-2.85 Rails

LM1086ISX-2.85 Tape and Reel

LM1086IS-3.3 Rails

LM1086ISX-3.3 Tape and Reel

LM1086IS-5.0 Rails

LM1086ISX-5.0 Tape and Reel

0˚C to +125˚C LM1086CS-ADJ Rails

LM1086CSX-ADJ Tape and Reel

LM1086CS-2.85 Rails

LM1086CSX-2.85 Tape and Reel

LM1086CS-3.3 Rails

LM1086CSX-3.3 Tape and Reel

LM1086CS-5.0 Rails

LM1086CSX-5.0 Tape and Reel

3-lead TO-220 −40˚C to +125˚C LM1086IT-ADJ Rails

LM1086IT-2.85 Rails

LM1086IT-3.3 Rails
LM1086IT-5.0 Rails

0˚C to +125˚C LM1086CT-ADJ Rails

LM1086CT-2.85 Rails

LM1086CT-3.3 Rails
LM1086CT-5.0 Rails

Note: D-Pak package also available. Contact National Semiconductor sales representative in your area.

TS3B

T03B

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Simplified Schematic

DS100948-34

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

Lead Temperature 260˚C, to 10 sec
ESD Tolerance (Note 4) 2000V

please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Maximum Input-to-Output Voltage Differential

LM1086-ADJ 29V
LM1086-2.85 27V
LM1086-3.3 27V

LM1086-5.0 25V
Power Dissipation (Note 2) Internally Limited
Junction Temperature (T

)(Note 3) 150˚C

J

Operating Ratings (Note 1)

Junction Temperature Range (T

″C″ Grade

Control Section 0˚C to 125˚C
Output Section 0˚C to 150˚C

″I″ Grade

Control Section −40˚C to 125˚C
Output Section −40˚C to 150˚C

) (Note 3)

J

Storage Temperature Range -65˚C to 150˚C

Electrical Characteristics

Typicals and limits appearing in normal type apply for TJ= 25˚C. Limits appearing in Boldface type apply over the entire junc­tion temperature range for operation.

Symbol Parameter Conditions

V

REF

V

OUT

Reference
Voltage

Output Voltage
(Note 7)

LM1086-ADJ

=

10mA, V

I

OUT

10mA ≤I

OUT

(Note 7)
LM1086-2.85

=

0mA, V

I

OUT

0 ≤ I

OUT≤IFULL LOAD

IN−VOUT

≤ I

FULL LOAD

=

5V

IN

, 4.35V≤ VIN≤18V

=

3V

,1.5V ≤ VIN−V

LM1086-3.3
I

OUT

0 ≤ I

=

OUT

0mA, V

≤ I

FULL LOAD

=

5V

IN

, 4.75V ≤ VIN≤18V

LM1086-5.0

∆V

OUT

Line Regulation
(Note 8)

=

0mA, V

I

OUT

0 ≤ I

OUT

LM1086-ADJ

=

10mA, 1.5V≤ (V

I

OUT

≤ I

FULL LOAD

=

8V

IN

, 6.5V ≤ VIN≤20V

IN-VOUT

LM1086-2.85

=

I

OUT

0mA, 4.35V ≤ V

IN

≤ 18V

LM1086-3.3
I

OUT

=

0mA, 4.5V ≤ V

IN

≤ 18V

LM1086-5.0

∆V

OUT

Load Regulation
(Note 8)

=

I

0mA, 6.5V ≤ V

OUT

LM1086-ADJ
(V

IN-VOUT

)=3V, 10mA ≤ I

IN

≤ 20V

LM1086-2.85

=

5V, 0 ≤ I

V

IN

OUT

≤ I

FULL LOAD

LM1086-3.3

=

5V, 0 ≤ I

V

IN

OUT

≤ I

FULL LOAD

LM1086-5.0

Dropout Voltage
(Note 9)

=

8V, 0 ≤ I

V

IN

LM1086-2.85/3.3/5/ADJ

=

1%,I

∆V

REF

≤ I

OUT

FULL LOAD

=

1.5A 1.3 1.5 V

OUT

) ≤ 15V

OUT

≤ I

FULL LOAD

OUT

≤ 15V

Min

(Note

1.238

1.225

2.82

2.79

3.267

3.235

4.950

4.900

Typ

(Note

6)

1.250

1.250

2.85

2.85

3.300

3.300

5.000

5.000

0.015

0.035

0.3

0.6

0.5

1.0

0.5

1.0

0.1

0.2

5)

3

6

3

7

5

10

Max

(Note6)Units

1.262

1.270VV

2.88

2.91

3.333

3.365VV

5.050

5.100VV

0.2

0.2

6

6

10

10

10

10

0.3

0.4

12

20

15

25

20

35

V
V

%
%

mV
mV

mV
mV

mV
mV

%
%

mV
mV

mV
mV

mV
mV

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Electrical Characteristics (Continued)

Typicals and limits appearing in normal type apply for TJ= 25˚C. Limits appearing in Boldface type apply over the entire junc­tion temperature range for operation.

Symbol Parameter Conditions

I

LIMIT

Current Limit LM1086-ADJ

V

IN−VOUT

V

IN−VOUT

=

5V

=

25V

Min

(Note

1.50

0.05

LM1086-2.85

=

8V 1.5 2.7 A

V

IN

LM1086-3.3

=

V

8V 1.5 2.7 A

IN

LM1086-5.0

=

10V 1.5 2.7 A

V

Minimum Load
Current (Note 10)

Quiescent
Current

IN

LM1086-ADJ

=

V

IN−VOUT

25V 5.0 10.0 mA

LM1086-2.85

≤ 18V 5.0 10.0 mA

V

IN

LM1086-3.3

≤ 18V 5.0 10.0 mA

V

IN

LM1086-5.0

≤ 20V 5.0 10.0 mA

V

IN

Thermal
Regulation

Ripple Rejection f

Adjust Pin

=

T

25˚C, 30ms Pulse 0.008 0.04

A

=

120Hz, C

RIPPLE

1.5A

LM1086-2.85, V
LM1086-3.3, V
LM1086-5.0 V

IN

=

25µF Tantalum, I

OUT

=

25µF, (V

ADJ

=

6V 60 72 dB

IN

=

6.3V 60 72 dB

IN

=

8V 60 68 dB

IN−VO

)=3V

OUT

=

LM1086 55 120 µA

Current
Adjust Pin

Current Change

10mA ≤ I

OUT

≤ I

FULL LOAD

, 1.5V ≤ (VIN−V

OUT

) ≤ 15V

Temperature
Stability

Long Term
Stability

RMS Output

=

T

125˚C, 1000Hrs

A

10Hz ≤ f≤ 10kHz 0.003

Noise

OUT

)

3-Lead TO-263: Control Section/Output Section
3-Lead TO-220: Control Section/Output Section

(%of V
Thermal

Resistance
Junction-to-Case

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is in­tended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.

Note 2: Power dissipation is kept in a safe range by current limiting circuitry. Refer to Overload Recovery in Application Notes.
Note 3: The maximum power dissipation is a function of T

=(T

is P

D

Note 4: For testing purposes, ESD was applied using human body model, 1.5kΩ in series with 100pF.
Note 5: Typical Values represent the most likely parametric norm.
Note 6: All limits are guaranteed by testing or statistical analysis.
Note 7: I

sipation for the LM1086 is only achievable over a limited range of input-to-output voltage.
Note 8: Load and line regulation are measured at constant junction temperature, and are guaranteed up to the maximum power dissipation of 15W. Power dissipa-

tion is determined by the input/output differential and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range.

Note 9: Dropout voltage is specified over the full output current range of the device.
Note 10: The minimum output current required to maintain regulation.

)/θJA. All numbers apply for packages soldered directly into a PC board. Refer to Thermal Considerations in the Application Notes.

J(max)–TA

is defined in the current limit curves. The I

FULL LOAD

, θJA, and TA. The maximum allowable power dissipation at any ambient temperature

J(max)

Curve defines current limit as a function of input-to-output voltage. Note that 15W power dis-

FULL LOAD

Typ

(Note

6)

5)

Max

(Note6)Units

2.7

0.15

60 75 dBLM1086-ADJ, C

0.2 5 µA

0.5

0.3 1.0

1.5/4.0

1.5/4.0

A
A

%

/W

%

%
%

˚C/W
˚C/W

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