NSC LM337T, LM337KSTEEL, LM337KMWC, LM337IMPX, LM337IMP Datasheet

LM137/LM337
3-Terminal Adjustable Negative Regulators

General Description

The LM137/LM337 are adjustable 3-terminal negative volt­age regulatorscapable of supplying in excess of −1.5A over
an output voltage range of −1.2V to −37V. These regulators
are exceptionally easy to apply, requiring only 2 external re­sistors to set the output voltage and 1 output capacitor for
frequency compensation. The circuit design has been opti­mized for excellent regulation and low thermal transients.
Further, the LM137 series features internal current limiting,
thermal shutdown and safe-area compensation, making
them virtually blowout-proof against overloads.

The LM137/LM337 serve a wide variety of applications in­cluding local on-card regulation, programmable-output volt­age regulation or precision current regulation. The LM137/
LM337 are ideal complements to the LM117/LM317
adjustable positive regulators.

Features

n Output voltage adjustable from −1.2V to −37V
n 1.5A output current guaranteed, −55˚C to +150˚C
n Line regulation typically 0.01%/V
n Load regulation typically 0.3

%

n Excellent thermal regulation, 0.002%/W

n 77 dB ripple rejection
n Excellent rejection of thermal transients
n 50 ppm/˚C temperature coefficient
n Temperature-independent current limit
n Internal thermal overload protection
n P

+

Product Enhancement tested

n Standard 3-lead transistor package
n Output is short circuit protected

LM137 Series Packages and Power
Capability

Rated Design

Device Package Power Load

Dissipation Current

LM137/337 TO-3 (K) 20W 1.5A

TO-39 (H) 2W 0.5A
LM337 TO-220 (T) 15W 1.5A
LM337 SOT-223

(MP)

2W 1A

Typical Applications Comparison between SOT-223 and

D-Pak (TO-252) Packages

Adjustable Negative Voltage Regulator

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Full output current not available at high input-output voltages

†

C1=1 µF solid tantalum or 10 µF aluminum electrolytic required for

stability
*C2=1 µF solid tantalum is required only if regulator is more than 4" from

power-supply filter capacitor
Output capacitors in the range of 1 µF to 1000 µF of aluminum or tantalum

electrolytic are commonly used to provide improved output impedance and
rejection of transients

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Scale 1:1

May 1999

LM137/LM337 3-Terminal Adjustable Negative Regulators

© 1999 National Semiconductor Corporation DS009067 www.national.com

Absolute Maximum Ratings (Notes 1, 4)

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

Power Dissipation Internally Limited
Input-Output Voltage Differential 40V
Operating Junction Temperature Range

LM137 −55˚C to +150˚C

LM337 0˚C to +125˚C
Storage Temperature −65˚C to +150˚C
Lead Temperature (Soldering, 10 sec.) 300˚C
Plastic Package (Soldering, 4 sec.) 260˚C
ESD Rating 2k Volts

Electrical Characteristics

(Note 1)

Parameter Conditions LM137 LM337 Units

Min Typ Max Min Typ Max

Line Regulation T

j

=

25˚C, 3V ≤ |V

IN−VOUT

| ≤ 40V 0.01 0.02 0.01 0.04%/V

(Note 2) I

L

=

10 mA

Load Regulation T

j

=

25˚C, 10 mA ≤ I

OUT

≤ I

MAX

0.3 0.5 0.3 1.0

%

Thermal Regulation T

j

=

25˚C, 10 ms Pulse 0.002 0.02 0.003 0.04%/W
Adjustment Pin Current 65 100 65 100 µA
Adjustment Pin Current Charge 10 mA ≤ I

L

≤ I

MAX

25 25µA

3.0V ≤ |V

IN−VOUT

| ≤ 40V,

T

A

=

25˚C

Reference Voltage T

j

=

25˚C (Note 3) −1.225 −1.250 −1.275 −1.213 −1.250 −1.287 V

3V ≤ |V

IN−VOUT

| ≤ 40V, (Note 3) −1.200 −1.250 −1.300 −1.200 −1.250 −1.300 V

10 mA ≤ I

OUT

≤ I

MAX

,P≤P

MAX

Line Regulation 3V ≤ |VIN−V

OUT

| ≤ 40V, (Note 2) 0.02 0.05 0.02 0.07%/V

Load Regulation 10 mA ≤ I

OUT

≤ I

MAX

, (Note 2) 0.3 1 0.3 1.5

%

Temperature Stability T

MIN

≤ Tj≤ T

MAX

0.6 0.6

%

Minimum Load Current |V

IN−VOUT

| ≤ 40V 2.5 5 2.5 10 mA

|V

IN−VOUT

| ≤ 10V 1.2 3 1.5 6 mA

Current Limit |V

IN−VOUT

| ≤ 15V
K, MP and T Package 1.5 2.2 3.5 1.5 2.2 3.7 A
H Package 0.5 0.8 1.8 0.5 0.8 1.9 A
|V

IN−VOUT

|=40V, T

j

=

25˚C
K, MP and T Package 0.24 0.4 0.15 0.4 A
H Package 0.15 0.17 0.10 0.17 A

RMS Output Noise,%of V

OUT

T

j

=

25˚C, 10 Hz ≤ f ≤ 10 kHz 0.003 0.003

%

Ripple Rejection Ratio V

OUT

=

−10V, f=120 Hz 60 60 dB

C

ADJ

=

10 µF 66 77 66 77 dB

Long-Term Stability T

j

=

125˚C, 1000 Hours 0.3 1 0.3 1

%

Thermal Resistance, Junction to
Case

H Package 12 15 12 15 ˚C/W
K Package 2.3 3 2.3 3 ˚C/W
T Package 4 ˚C/W

Thermal Resistance, Junction to
Ambient (No Heat Sink)

H Package 140 140 ˚C/W
K Package 35 35 ˚C/W
T Package

MP Package

50

170

˚C/W
˚C/W

Note 1: Unless otherwise specified, these specifications apply −55˚C ≤Tj≤ +150˚C for the LM137, 0˚C ≤ Tj≤ +125˚C for the LM337; VIN−V

OUT

=

5V; and I

OUT

=

0.1A for the TO-39 package and I

OUT

=

0.5A for the TO-3, SOT-223 and TO-220 packages. Althoughpower dissipation is internally limited, these specifications

are applicable for power dissipations of 2W for the TO-39 and SOT-223 (see Application Hints), and 20W for the TO-3, and TO-220. I

MAX

is 1.5Afor the TO-3,

SOT-223 and TO-220 packages, and 0.2Afor the TO-39 package.
Note 2: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are cov-

ered under the specification for thermalregulation. Load regulation is measured on the output pin at a point

1

⁄8" below the base of theTO-3 and TO-39 packages.

Note 3: Selected devices with tightened tolerance reference voltage available.
Note 4: Refer to RETS137H drawing for LM137H or RETS137K drawing for LM137K military specifications.

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Schematic Diagram

Thermal Regulation

When power is dissipated in an IC, a temperature gradient
occurs across the IC chip affecting the individual IC circuit
components. With an ICregulator,this gradient can beespe­cially severesince powerdissipation islarge. Thermal regu­lation is the effect of these temperature gradients on output
voltage (in percentage output change) per Watt of power
change in a specified time. Thermal regulation error is inde­pendent of electrical regulation or temperature coefficient,
and occurs within5 ms to 50ms after achange in power dis­sipation. Thermal regulationdepends on IClayout as wellas
electrical design. The thermal regulation of avoltage regula­tor is defined as the percentage change of V

OUT

, per Watt,
within the first 10 ms after a step of power is applied. The
LM137’s specification is 0.02%/W, max.

In

Figure 1

, a typical LM137’s output drifts only 3 mV (or

0.03%of V

OUT

=

−10V) when a 10W pulse is applied for
10 ms. This performance is thus wellinside the specification
limit of 0.02%/W x 10W=0.2%max. When the10W pulse is
ended, the thermal regulation again showsa3mVstep at
the LM137 chip cools off. Note that the load regulation error
of about 8 mV (0.08%) is additional to thethermal regulation
error.In

Figure 2

, when the10W pulse isapplied for 100ms,
the output drifts only slightly beyond the drift in the first
10 ms, andthe thermal error stays well within 0.1%(10 mV).

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LM137, V

OUT

=

−10V

V

IN−VOUT

=

−40V

I

IL

=

0A→0.25A→0A

Vertical sensitivity, 5 mV/div

FIGURE 1.

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Thermal Regulation (Continued)

Connection Diagrams

Application Hints

When a value for θ

(H−A)

is found using the equation shown,

a heatsink mustbe selected that hasa value thatis less than
or equal to this number.

HEATSINKING SOT-223 PACKAGE PARTS

The SOT-223 (“MP”) packages use a copper plane on the
PCB and the PCB itself as a heatsink. To optimize the heat
sinking ability of the plane and PCB, solder the tab of the
package to the plane.

Figures 3, 4

show the information for the SOT-223 package.

Figure 4

assumes a θ

(J−A)

of 75˚C/W for1 ounce copperand
51˚C/W for 2 ounce copper and a maximum junction tem­perature of 125˚C.

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LM137, V

OUT

=

−10V

V

IN−VOUT

=

−40V

I

L

=

0A→0.25A→0A

Horizontal sensitivity, 20 ms/div

FIGURE 2.

TO-3

Metal Can Package

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Case is Input

Bottom View

Order Number LM137K/883

LM137KPQML and LM137KPQMLV(Note 5)

See NS Package Number K02C

Order Number LM337K STEEL

See NS Package Number K02A

TO-39

Metal Can Package

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Case Is Input

Note 5: See STD Mil DWG 5962P99517 for Radiation Tolerant Devices

Bottom View

Order Number LM137H, LM137H/883 or LM337H

LM137HPQML and LM137HPQMLV(Note 5)

See NS Package Number H03A

TO-220

Plastic Package

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Front View

Order Number LM337T

See NS Package Number T03B

3-Lead SOT-223

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Front View

Order Number LM337IMP

Package Marked N02ASee NS Package Number MA04A

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Application Hints (Continued)

Please see AN1028 for power enhancement techniques to
be used with the SOT-223 package.

Typical Applications

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FIGURE 3. θ

(J−A)

vs Copper (2 ounce) Area for the

SOT-223 Package

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FIGURE 4. Maximum Power Dissipation vs T

AMB

for

the SOT-223 Package

Adjustable Lab Voltage Regulator

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Full output current not available
at high input-output voltages
*The 10 µF capacitors are optional to improve ripple rejection

Current Regulator

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Negative Regulator with Protection Diodes

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*

When CLis larger than 20 µF, D1 protects the LM137 in case the input

supply is shorted

**

When C2 is larger than 10 µF and −V

OUT

is larger than −25V, D2

protects the LM137 in case the output is shorted

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Typical Applications (Continued)

−5.2V Regulator with Electronic Shutdown

*

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*Minimum output≅−1.3V when control input is low

Adjustable Current Regulator

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High Stability −10V Regulator

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Typical Performance Characteristics (K Steel and T Packages)

Load Regulation

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Current Limit

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Adjustment Current

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Dropout Voltage

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Temperature Stability

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Minimum Operating Current

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Ripple Rejection

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Ripple Rejection

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Ripple Rejection

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Output Impedance

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Line Transient Response

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Load Transient Response

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Physical Dimensions inches (millimeters) unless otherwise noted

Metal Can Package (H)

Order Number LM137H, LM137H/883 or LM337H

NS Package Number H03A

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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

Metal Can Package (K)

Order Number LM337K STEEL

NS Package Number K02A

Mil-Aero Metal Can Package (K)

Order Number LM137K/883

NS Package Number K02C

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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

3-Lead SOT-223 Package

Order Number LM337IMP

NS Package Number M04A

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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

LIFE SUPPORT POLICY

NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.

2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.

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TO-220 Plastic Package (T)

Order Number LM337T

NS Package Number T03B

LM137/LM337 3-Terminal Adjustable Negative Regulators

National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the rightat any time without noticeto change said circuitry and specifications.