NSC LM1084ISX-12, LM1084IS-ADJ, LM1084IS-5.0, LM1084IS-12, LM1084IT-ADJ Datasheet

LM1084 5A Low Dropout Positive Regulators

September 1999

General Description

The LM1084 is a series of low dropout voltage positive regulators with a maximum dropout of 1.5V at 5A of load current. It has thesamepin-out as National Semiconductor’s industry standard LM317.

The LM1084 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: 3.3V, 5.0V and 12.0V. The fixed versions intergrate the adjust resistors.

The LM1084 circuit includes a zener trimmed bandgap reference, current limiting and thermal shutdown.

The LM1084 series is available in TO-220 and TO-263 packages.

Connection Diagrams

TO-220

DS100946-36

Top View

Features

n Available in 3.3V, 5.0V, 12V and Adjustable Versions n Current Limiting and Thermal Protection n Output Current 5A n Industrial Temperature Range −40˚C to 125˚C n Line Regulation 0.015%(typical) n Load Regulation 0.1%(typical)

Applications

n Post Regulator for Switching DC/DC Conveter n High Efficiency Linear Regulators n Battery Charger

TO-263

DS100946-35

Top View

Basic Functional Diagram, Adjustable Version

DS100946-65

Ordering Information

Package Temperature Range Part Number Transport Media NSC Drawing

3-lead TO-263 −40˚C to +125˚C LM1084IS-ADJ Rails

LM1084ISX-ADJ Tape and Reel

LM1084IS-12 Rails

LM1084ISX-12 Tape and Reel

LM1084IS-3.3 Rails

LM1084ISX-3.3 Tape and Reel

LM1084IS-5.0 Rails

LM1084ISX-5.0 Tape and Reel

3-lead TO-220 −40˚C to + 125˚C LM1084IT-ADJ Rails

LM1084IT-12 Rails LM1084IT-3.3 Rails LM1084IT-5.0 Rails

Simplified Schematic

TS3B

T03B

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DS100946-34

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Junction Temperature (T

)(Note 3) 150˚C

J

Storage Temperature Range -65˚C to 150˚C Lead Temperature 260˚C, to 10 sec ESD Tolerance (Note 4) 2000V

Maximum Input to Output Voltage Differential

LM1084-ADJ 29V LM1084-12 18V LM1084-3.3 27V LM1084-5.0 25V

Operating Ratings (Note 1)

Junction Temperature Range (T

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

) (Note 3)

J

Power Dissipation (Note 2) Internally Limited

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

Reference Voltage

LM1084-ADJ

=

10mA, V

I

OUT

10mA ≤I

OUT

25V

IN−VOUT

≤ I

FULL LOAD

=

3V

,1.5V ≤ (VIN−V

(Note 7)

V

OUT

Output Voltage (Note 7)

LM1084-3.3

=

0mA, V

I

OUT

0 ≤ I

OUT≤IFULL LOAD

=

8V

IN

, 4.8V≤ VIN≤15V

LM1084-5.0 I

OUT

0 ≤ I

=

OUT

0mA, V

≤ I

FULL LOAD

=

8V

IN

, 6.5V ≤ VIN≤ 20V

LM1084-12

∆V

OUT

Line Regulation (Note 8)

=

I

0mA, V

OUT

0 ≤ I

OUT

LM1084-ADJ

=

10mA, 1.5V≤ (V

I

OUT

≤ I

FULL LOAD

=

15V

IN

, 13.5V ≤ VIN≤ 25V

IN-VOUT

LM1084-3.3 I

OUT

=

0mA, 4.8V ≤ V

IN

≤ 15V

LM1084-5.0 I

OUT

=

0mA, 6.5V ≤ V

IN

≤ 20V

LM1084-12

∆V

OUT

Load Regulation (Note 8)

=

I

0mA, 13.5V ≤ V

OUT

LM1084-ADJ (V

IN-VOUT

)=3V, 10mA ≤ I

IN

≤ 25V

OUT

LM1084-3.3

=

5V, 0 ≤ I

V

IN

OUT

≤ I

FULL LOAD

LM1084-5.0

=

8V, 0 ≤ I

V

IN

OUT

≤ I

FULL LOAD

LM1084-12

Dropout Voltage (Note 9)

=

15V, 0 ≤ I

V

IN

LM1084-3.3/5/12/ADJ

=

1%,I

∆V

REF

≤ I

OUT

FULL LOAD

=

5A 1.3 1.5 V

OUT

) ≤ 15V

≤ I

FULL LOAD

OUT

) ≤

Min

(Note

6)

1.238

1.225

3.270

3.235

4.950

4.900

11.880

11.760

Typ

(Note

5)

1.250

3.300

5.000

12.000

0.015

0.035

0.5

1.0

0.5

1.0

2.0

0.1

0.2

3

7

5

10

12

24

Max

(Note6)Units

1.262

1.270

3.330

3.365

5.050

5.100

12.120

12.240VV

0.2

6

10

25

0.3

0.4

15

20

35

36

72

V V

% %

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 LM1084-ADJ

V

IN−VOUT

V

IN−VOUT

=

5V

=

25V

Min

(Note

6)

5.5

0.3

LM1084-3.3

=

8V 5.5 8.0 A

V

IN

LM1084-5.0

=

V

10V 5.5 8.0 A

IN

LM1084-12

=

17V 5.5 8.0 A

V

Minimum Load Current (Note

10) Quiescent

Current

IN

LM1084-ADJ

=

V

IN−VOUT

25V

LM1084-3.3

=

18V 5.0 10.0 mA

V

IN

LM1084-5.0

≤ 20V 5.0 10.0 mA

V

IN

LM1084-12

≤ 25V 5.0 10.0 mA

V

IN

Thermal Regulation

Ripple Rejection f

Adjust Pin

=

T

25˚C, 30ms Pulse 0.003 0.015

A

=

120Hz,=C

RIPPLE

=

5A

LM1084-3.3, V LM1084-5.0, V LM1084-12 V

ADJ IN IN

=

IN

=

25µF Tantalum, I

OUT

,=25µF, (VIN−VO)=3V

=

6.3V 60 72 dB

=

8V 60 68 dB

OUT

60 75 dBLM1084-ADJ, C

15V 54 60 dB

LM1084 55 120 µA

Current Adjust Pin

Current Change

10mA ≤ I

1.5V ≤ V

≤ I

OUT

IN−VOUT

FULL LOAD

≤ 25V

,

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

dissipation for the LM1084 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 30W. 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.

)/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

FULLLOAD

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

J(max)

Curve defines the current limit as a function of input-to-output voltage. Note that 30W power

FULLLOAD

Typ

(Note

5)

Max

(Note6)Units

8.0

0.6

5 10.0 mA

0.2 5 µA

0.5

0.3 1.0

0.65/2.7

˚C/W ˚C/W

A A

%

/W

%

% %

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Electrical Characteristics (Continued)

Note 10: The minimum output current required to maintain regulation.

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