LM337L
LM337L 3-Terminal Adjustable Regulator
Literature Number: SNVS780C
LM337L
3-Terminal Adjustable Regulator
General Description
The LM337L is an adjustable 3-terminal negative voltage
regulator capable of supplying 100mA over a 1.2V to 37V
output range. It is exceptionally easy to use and requires
only two external resistors to set the output voltage. Further-
more, both line and load regulation are better than standard
fixed regulators. Also, the LM337L is packaged in a standard
TO-92 transistor package which is easy to use.
In addition to higher performance than fixed regulators, the
LM337L offers full overload protection. Included on the chip
are current limit, thermal overload protection and safe area
protection. All overload protection circuitry remains fully func-
tional even if the adjustment terminal is disconnected.
Normally, only a single 1µF solid tantalum output capacitor is
needed unless the device is situated more than 6 inches
from the input filter capacitors, in which case an input bypass
is needed. A larger output capacitor can be added to improve
transient response. The adjustment terminal can be by-
passed to achieve very high ripple rejection ratios which are
difficult to achieve with standard 3-terminal regulators.
Besides replacing fixed regulators, the LM337L is useful in a
wide variety of other applications. Since the regulator is
“floating” and sees only the input-to-output differential volt-
age, supplies of several hundred volts can be regulated as
long as the maximum input-to-output differential is not ex-
ceeded.
Also, it makes an especially simple adjustable switching
regulator, a programmable output regulator, or by connecting
a fixed resistor between the adjustment and output, the
LM337L can be used as a precision current regulator. Sup-
plies with electronic shutdown can be achieved by clamping
the adjustment terminal to ground which programs the out-
put to 1.2V where most loads draw little current.
The LM337L is available in a standard TO-92 transistor
package, SO-8 surface mount package, and in our new 12
mil diameter bump micro SMD package. The LM337L is
rated for operation over a −25˚C to +125˚C range.
For applications requiring greater output current in excess of
0.5A and 1.5A, see LM137 series data sheets. For the
positive complement, see series LM117 and LM317L data
sheets.
Features
nAdjustable output down to 1.2V
nGuaranteed 100mA output current
nLine regulation typically 0.01%/V
nLoad regulation typically 0.1%
nCurrent limit constant with temperature
nEliminates the need to stock many voltages
nStandard 3-lead transistor package
n80 dB ripple rejection
nOutput is short circuit protected
nAvailable in the 6-Bump micro SMD package
nSee AN-1112 for micro SMD considerations
Typical Application
1.2V-25V Adjustable Regulator
00913403
June 2005
LM337L 3-Terminal Adjustable Regulator
© 2005 National Semiconductor Corporation DS009134 www.national.com
Connection Diagrams
3-Pin TO92 8-Pin SOIC
00913401
Bottom View 00913402
Top View
6-Bump micro SMD micro SMD Laser mark
00913408
00913407
Ordering Information
Package Part Number Package Marking Transport Media NSC Drawing
3-Pin TO92 LM337LZ LM337LZ 1800 per Bag Z03A
8-Pin SOIC LM337LM LM337LM Rails M08A
LM337LMX 2.5k Units Tape and Reel
6-Bump micro SMD LM337LBL PA 250 Units Tape and Reel BLA06FNB
LM337LBLX 3k Units Tape and Reel
LM337L
www.national.com 2
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Power Dissipation Internally Limited
Input–Output Voltage Differential 40V
Operating Junction
Temperature Range −25˚C to +125˚C
Storage Temperature −55˚C to +150˚C
Lead Temperature
(Soldering, 10 sec.) 300˚C
Plastic Package (Soldering 4 sec.) 260˚C
ESD Rating 1.5kV (Note 5)
Electrical Characteristics (Note 2)
Parameter Conditions Min Typ Max Units
Line Regulation T
A
= 25˚C, 3V ≤|V
IN
−V
OUT
|≤40V, 0.01 0.04 %/V
(Note 3)
Load Regulation T
A
= 25˚C, 5mA ≤I
OUT
≤I
MAX
, (Note 3) 0.1 0.5 %
Thermal Regulation T
A
= 25˚C, 10ms Pulse 0.04 0.2 %/W
Adjustment Pin Current 50 100 µA
Adjustment Pin Current Change 5mA ≤I
L
≤100mA 0.2 5 µA
3V ≤|V
IN
−V
OUT
|≤40V
Reference Voltage 3V ≤|V
IN
−V
OUT
|≤40V, (Note 4) 1.20 1.25 1.30 V
10mA ≤I
OUT
≤100mA, P ≤625mW
Line Regulation 3V ≤|V
IN
−V
OUT
|≤40V, (Note 3) 0.02 0.07 %/V
Load Regulation 5mA ≤I
OUT
≤100mA, (Note 3) 0.3 1.5 %
Temperature Stability T
MIN
≤T
j
≤T
MAX
0.65 %
Minimum Load Current |V
IN
−V
OUT
|≤40V 3.5 5 mA
3V ≤|V
IN
−V
OUT
|≤15V 2.2 3.5 mA
Current Limit 3V ≤|V
IN
−V
OUT
|≤13V 100 200 320 mA
|V
IN
−V
OUT
| = 40V 25 50 120 mA
Rms Output Noise, % of V
OUT
T
A
= 25˚C, 10Hz ≤f≤10kHz 0.003 %
Ripple Rejection Ratio V
OUT
= −10V, F = 120 Hz, C
ADJ
= 0 65 dB
C
ADJ
= 10µF 66 80 dB
Long-Term Stability T
A
= 125˚C 0.3 1 %
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: Unless otherwise specified, these specifications apply −25˚C ≤TJ≤+ 125˚C for the LM337L; |VIN −V
OUT| = 5V and IOUT = 40mA. Although power
dissipation is internally limited, these specifications are applicable for power dissipations up to 625 mW. IMAX is 100mA.
Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are
covered under the specification for thermal regulation.
Note 4: Thermal resistance of the TO-92 package is 180˚C/W junction to ambient with 0.4" leads from a PC board and 160˚C/W junction to ambient with 0.125" lead
length to PC board. The M package θJA is 180˚C/W in still air. The 6-Bump micro SMD package θJA is 290˚C/W in still air.
Note 5: Human body model, 1.5kΩin series with 100pF.
LM337L
www.national.com3
Typical Applications
1.2V-25V Adjustable Regulator
00913403
Full output current not available at high input-output voltages
†C1 = 1µF solid tantalum or 10µF aluminum electrolytic required for
stability
*C2 = 1µF solid tantalum is required only if regulator is more than 4" from
power supply filter capacitor
Regulator with Trimmable Output Voltage
00913404
Trim Procedure:
—If V
OUT is −23.08V or bigger, cut out R3 (if smaller, don’t cut it out).
— Then if VOUT is −22.47V or bigger, cut out R4 (if smaller, don’t).
— Then if VOUT is −22.16V or bigger, cut out R5 (if smaller, don’t).
This will trim the output to well within 1% of −22.00 VDC, without any of the
expense or trouble of a trim pot (see LB-46). Of course, this technique can
be used at any output voltage level.
LM337L
www.national.com 4
Physical Dimensions inches (millimeters)
unless otherwise noted
8-Pin SOIC
NS Package Number M08A
3-Pin TO-92 (Z)
NS Package Number Z03A
LM337L
www.national.com5
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
NOTES: UNLESS OTHERWISE SPECIFIED
1. EPOXY COATING.
2. 63Sn/37Pb EUTECTIC BUMP.
3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.
4. PIN A1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION. REMAINING PINS ARE NUMBERED
COUNTERCLOCKWISE.
5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH. X2 IS PACKAGE LENGTH AND X3 IS
PACKAGE HEIGHT (SEE TABLE, SHEET 2). EXAMPLE: BLA06AFA HAS WIDTH = 1006. LENGTH = 1641, HEIGHT = 795.
6. REFERENCE JEDEC REGISTRATION MO-211, VARIATION BC.
6-Bump micro SMD
NS Package Number BLA06FNB
X1 = 1133µm X2 = 1819µm X3 = 945µm
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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.
BANNED SUBSTANCE COMPLIANCE
National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products
Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain
no ‘‘Banned Substances’’ as defined in CSP-9-111S2.
Leadfree products are RoHS compliant.
National Semiconductor
Americas Customer
Support Center
Email: new.feedback@nsc.com
Tel: 1-800-272-9959
National Semiconductor
Europe Customer Support Center
Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 8790
National Semiconductor
Asia Pacific Customer
Support Center
Email: ap.support@nsc.com
National Semiconductor
Japan Customer Support Center
Fax: 81-3-5639-7507
Email: jpn.feedback@nsc.com
LM337L 3-Terminal Adjustable Regulator
Tel: 81-3-5639-7560www.national.com
LM337L 3-Terminal Adjustable Regulator
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements,
and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should
obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are
sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard
warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where
mandated by government requirements, testing of all parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and
applications using TI components. To minimize the risks associated with customer products and applications, customers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right,
or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information
published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a
warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual
property of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied
by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive
business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional
restrictions.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all
express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not
responsible or liable for any such statements.
TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably
be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing
such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products
and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be
provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in
such safety-critical applications.
TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are
specifically designated by TI as military-grade or "enhanced plastic."Only products designated by TI as military-grade meet military
specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at
the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use.
TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are
designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated
products in automotive applications, TI will not be responsible for any failure to meet such requirements.
Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products Applications
Audio www.ti.com/audio Communications and Telecom www.ti.com/communications
Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers
Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps
DLP®Products www.dlp.com Energy and Lighting www.ti.com/energy
DSP dsp.ti.com Industrial www.ti.com/industrial
Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical
Interface interface.ti.com Security www.ti.com/security
Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense
Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive
Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video
RFID www.ti-rfid.com
OMAP Mobile Processors www.ti.com/omap
Wireless Connectivity www.ti.com/wirelessconnectivity
TI E2E Community Home Page e2e.ti.com
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright ©2011, Texas Instruments Incorporated