Sample &
Buy
Product
Folder
Support &
Community
Tools &
Software
Technical
Documents
LM237, LM337
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
LMx37 3-Terminal Adjustable Regulators
1 Features
3 Description
•
The LM237 and LM337 are adjustable 3-terminal
negative-voltage regulators capable of supplying in
excess of –1.5 A over an output voltage range of –1.2
V to –37 V. They require only two external resistors
to set the output voltage and one output capacitor for
frequency compensation.
1
•
•
•
•
•
•
Output Voltage Range Adjustable From
–1.2 V to –37 V
Output Current Capability of 1.5 A Max
Input Regulation Typically 0.01% Per InputVoltage Change
Output Regulation Typically 0.3%
Peak Output Current Constant Over Temperature
Range of Regulator
Ripple Rejection Typically 77 dB
Direct Replacement for Industry-Standard LM237
and LM337
Device Information(1)
PART NUMBER
LMx37
•
•
•
BODY SIZE (NOM)
10.16 mm x 8.82 mm
TO-263 (4)
10.16 mm x 9.02 mm
TO-252 (4)
6.6 mm x 6.10 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
2 Applications
•
PACKAGE
TO-220 (4)
Applications Requiring Negative Output Voltage or
Precision Current Regulation
Consumer Electronics
End Equipment
Portable Applications
4 Simplified Schematic
LM237
or
LM337
INPUT
VI
OUTPUT
VO
ADJUSTMENT
R1
C1
C2
+
+
R2
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LM237, LM337
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Simplified Schematic.............................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
1
2
3
4
7.1
7.2
7.3
7.4
7.5
7.6
7.7
4
4
4
4
5
5
6
Absolute Maximum Ratings .....................................
ESD Ratings..............................................................
Recommended Operating Conditions......................
Thermal Information ..................................................
Electrical Characteristics..........................................
Electrical Characteristics..........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 7
8.1 Overview ................................................................... 7
8.2 Functional Block Diagram ......................................... 7
8.3 Design Schematic ..................................................... 8
8.4 Feature Description................................................... 8
8.5 Device Functional Modes.......................................... 8
9
Application and Implementation .......................... 9
9.1 Application Information.............................................. 9
9.2 Typical Application ................................................... 9
10 Power Supply Recommendations ..................... 10
11 Layout................................................................... 11
11.1 Layout Guidelines ................................................. 11
11.2 Layout Example .................................................... 11
12 Device and Documentation Support ................. 11
12.1
12.2
12.3
12.4
Related Links ........................................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
11
11
11
11
13 Mechanical, Packaging, and Orderable
Information ........................................................... 11
5 Revision History
Changes from Revision K (November 2007) to Revision L
Page
•
Added Applications, Device Information table, Pin Functions table, ESD Ratings table, Thermal Information table,
Typical Characteristics, Feature Description section, Device Functional Modes, Application and Implementation
section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and
Mechanical, Packaging, and Orderable Information section. ................................................................................................. 1
•
Deleted Ordering Information table. ....................................................................................................................................... 1
2
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
LM237, LM337
www.ti.com
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
6 Pin Configuration and Functions
OUTPUT
INPUT
ADJUSTMENT
LM337...KCS (TO-220) PACKAGE
(TOP VIEW)
INPUT
INPUT
LM237, LM337...KC (TO-220) PACKAGE
(TOP VIEW)
LM337...KTE, KTP, OR KVU PACKAGE
(TOP VIEW)
LM337...KTT (TO-263) PACKAGE
(TOP VIEW)
INPUT
ADJUSTMENT
OUTPUT
INPUT
OUTPUT
INPUT
OUTPUT
INPUT
ADJUSTMENT
INPUT
ADJUSTMENT
Pin Functions
PIN
NAME
NO.
TYPE
DESCRIPTION
ADJUSTMENT
1
I
Adjustment pin for the output voltage. Connect two external
resistors to adjust the output voltage.
INPUT
2
I
Input voltage. The input voltage and current will be
designated VI and II respectively.
OUTPUT
3
O
Output voltage. The output voltage and current will be
designated VO and IO respectively.
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
3
LM237, LM337
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
www.ti.com
7 Specifications
7.1 Absolute Maximum Ratings
over operating temperature ranges (unless otherwise noted) (1)
MIN
VI – VO
Input-to-output differential voltage
TJ
Operating virtual junction temperature
Lead temperature
Tstg
(1)
MAX
UNIT
–40
V
150
°C
260
°C
150
°C
1.6 mm (1/16 in) from case for 10 s
Storage temperature range
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating
Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
7.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins (1)
1500
Charged device model (CDM), per JEDEC specification JESD22-C101,
all pins (2)
1500
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.3
Recommended Operating Conditions
MIN
VI-VO
Input-to-output differential voltage
IO
Output current
TJ
Operating virtual junction temperature
MAX
-2.5
-37
|VI – VO| ≤ 40 V, P ≤ 15 W
10
1500
|VI – VO| ≤ 10 V, P ≤ 15 W
6
1500
LM237
–25
150
LM337
0
125
UNIT
mA
°C
7.4 Thermal Information
LM237
THERMAL METRIC (1)
RθJA
Junction-to-ambient thermal resistance
RθJC(top
Junction-to-case (top) thermal resistance
LMx37
LM337
KC
KCS
KTE
KTP
KTT
KVU
4 PINS
4 PINS
4 PINS
4 PINS
4 PINS
4 PINS
24.8
24.8
23
28
25.3
30.3
3
3
3
19
30.3
N/A
UNIT
°C/W
)
(1)
4
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report (SPRA953).
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
LM237, LM337
www.ti.com
7.5
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
Electrical Characteristics
over recommended ranges of operating virtual junction temperature (unless otherwise noted)
TEST CONDITIONS (1)
PARAMETER
Input regulation (2)
Ripple rejection
VI – VO = –3 V to –40 V
LM237
MIN
LM337
TYP
MAX
TJ = 25°C
0.01
TJ = MIN to MAX
0.02
VO = –10 V, f = 120 Hz
MIN
TYP
MAX
0.02
0.01
0.04
0.05
0.02
0.07
60
VO = –10 V, f = 120 Hz, CADJ = 10 μF
66
|VO| ≤ 5 V
IO = 10 mA to 1.5 A,
TJ = 25°C
IO = 10 mA to 1.5 A
66
0.3%
50
0.5%
0.3%
—
|VO| ≤ 5 V
50
70
mV
|VO| ≥ 5 V
1%
1.5%
—
TJ = MIN to MAX
Output-voltage long-term drift
After 1000 h at TJ = MAX and VI – VO = –40 V
Output noise voltage
f = 10 Hz to 10 kHz, TJ = 25°C
Minimum output current to
maintain regulation
|VI – VO| ≤ 40 V
2.5
5
2.5
10
|VI – VO| ≤ 10 V
1.2
3
1.5
6
0.6%
0.3%
|VI – VO| ≤ 15 V
|VI – VO| ≤ 40 V, TJ = 25°C
Change in ADJUSTMENT
current
VI – VO = –2.5 V to –40 V, IO = 10 mA to MAX,
TJ = 25°C
Reference voltage (OUTPUT
to ADJUSTMENT)
VI – VO = –3 V to –40 V,
IO = 10 mA to 1.5 A,
P ≤ rated dissipation
Thermal regulation
Initial TJ = 25°C, 10-ms pulse
(2)
7.6
0.6%
1%
0.3%
0.003%
TJ = 25°C
TJ = MIN to MAX
—
1%
0.003%
1.5
2.2
1.5
2.2
0.24
0.4
0.15
0.4
—
—
mA
A
65
100
65
100
μA
2
5
2
5
μA
–1.225
–1.25
–1.275
–1.213
–1.25
–1.287
–1.2
–1.25
–1.3
–1.2
–1.25
–1.3
0.002
0.02
0.003
0.04
ADJUSTMENT current
(1)
mV
1%
Output-voltage change with
temperature
Peak output current
%/V
dB
77
25
|VO| ≥ 5 V
Output regulation
60
77
UNIT
V
%/W
Unless otherwise noted, the following test conditions apply: |VI – VO| = 5 V and IO = 0.5 A. For conditions shown as MIN or MAX, use
the appropriate value specified under recommended operating conditions. All characteristics are measured with a 0.1-μF capacitor
across the input and a 1-μF capacitor across the output. Pulse-testing techniques are used to maintain the junction temperature as close
to the ambient temperature as possible. Thermal effects must be taken into account separately.
Input regulation is expressed here as the percentage change in output voltage per 1-V change at the input.
Electrical Characteristics
TJ = 25°C
Input regulation (2)
Ripple rejection
LM237, LM337
TEST CONDITIONS (1)
PARAMETER
MIN
VI – VO = –3 V to –40 V
VO = –10 V, f = 120 Hz
TYP
MAX
0.01
0.04
60
VO = –10 V, f = 120 Hz, CADJ = 10 μF
66
50
mV
1%
—
Output regulation
IO = 10 mA to 1.5 A
Output noise voltage
f = 10 Hz to 10 kHz
Minimum output current to maintain
regulation
|VI – VO| ≤ 40 V
2.5
10
|VI – VO| ≤ 10 V
1.5
6
Peak output current
|VO| ≥ 5 V
0.3%
0.003%
|VI – VO| ≤ 15 V
1.5
2.2
|VI – VO| ≤ 40 V
0.15
0.4
ADJUSTMENT current
Change in ADJUSTMENT current
VI – VO = –2.5 V to –40 V, IO = 10 mA to MAX
Reference voltage
(OUTPUT to ADJUSTMENT)
VI – VO = –3 V to –40 V, IO = 10 mA to 1.5 A,
P ≤ rated dissipation
(1)
(2)
–1.213
%/V
dB
77
|VO| ≤ 5 V
UNIT
—
mA
A
65
100
μA
2
5
μA
–1.25
–1.287
V
Unless otherwise noted, the following test conditions apply: |VI – VO| = 5 V and IO = 0.5 A. All characteristics are measured with a 0.1μF capacitor across the input and a 1-μF capacitor across the output. Pulse-testing techniques are used to maintain the junction
temperature as close to the ambient temperature as possible. Thermal effects must be taken into account separately.
Input regulation is expressed here as the percentage change in output voltage per 1-V change at the input.
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
5
LM237, LM337
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
www.ti.com
7.7 Typical Characteristics
Adjustment to output voltage (V)
±1.240
±1.250
V(REF)
±1.260
0
300
600
900
1200
Load current (mA)
1500
C001
Figure 1. Adjustment Voltage vs Load current (VIN = -4.3 V)
6
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
LM237, LM337
www.ti.com
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
8 Detailed Description
8.1 Overview
The LMx37 devices are adjustable 3-terminal negative-voltage regulators capable of supplying in excess of –1.5
A over an output voltage range of –1.2 V to –37 V. They are exceptionally easy to use, requiring only two
external resistors to set the output voltage and one output capacitor for frequency compensation. The current
design is optimized for excellent regulation and low thermal transients. In addition, LM237 and LM337 feature
internal current limiting, thermal shutdown, and safe-area compensation, making them virtually immune to failure
by overloads. The LMx37 devices serve a wide variety of applications, including local on-card regulation,
programmable output-voltage regulation, and precision current regulation.
8.2 Functional Block Diagram
OUTPUT
IADJ
+
ADJUST
+ 1.25 V
Over temp
& over
current
protection
INPUT
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
7
LM237, LM337
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
www.ti.com
8.3 Design Schematic
ADJUSTMENT
OUTPUT
INPUT
8.4 Feature Description
8.4.1 Output Voltage Adjustment
The ADJUSTMENT pin serves as a voltage adjustment reference for the output. The ADJUSTMENT pin can be
attached to a resistor divider circuit to adjust its own voltage level. The reference voltage VADJUSTMENT will
typically be 1.25 V higher than VO.
8.5 Device Functional Modes
8.5.1 Adjustable Output Mode
The device has a single functional mode: Adjustable output voltage mode. A resistor divider circuit on the
ADJUSTMENT pin determines the output voltage.
8
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
LM237, LM337
www.ti.com
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
9.1.1 General Configurations
LM237
or
LM337
RS
VI
INPUT
IOUT
OUTPUT
VO
ADJUSTMENT
RS =
1.25 V
ILIMIT
Figure 2. Current-Limiting Circuit
This application uses the LMx37 device's reference voltage, combined with the series resistor RS, to limit the
current to 1.25 V ÷ RS
9.2 Typical Application
LM237
or
LM337
INPUT
VI
OUTPUT
VO
ADJUSTMENT
R1
C1
C2
+
+
R2
Figure 3. Adjustable Negative-Voltage Regulator
9.2.1 Design Requirements
• 1-µF solid tantalum on the input pin if the regulator is more than 10 cm from the power supply filter capacitor
• 1-µF solid tantalum or 10-µF aluminum electrolytic capacitor is required on the output pin for stability.
• R1, which is usually 120 Ω as part of the resistor divider.
• R2, which can be varied to change the value of VO.
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
9
LM237, LM337
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
www.ti.com
Typical Application (continued)
9.2.2 Detailed Design Procedure
VO is determined by the values of R1 and R2. Choosing R1 = 120 Ω means that about 10.42 mA of current will
flow through R1. The ~10 mA of current satisfies the minimum operating current and renders IREF negligible.
Since the current is coming from ground, the same amount of current will flow through R2. Therefore, the size of
R2 will be the dominant factor in adjusting VO. The relationship between R1, R2, and VO is as follows:
æ - VO
ö
- 1÷
R2 = R1ç
è -1.25 ø
where VO is the output in volts.
(1)
9.2.3 Application Curves
80
CADJ = 10 µF
CADJ = 0 µF
Ripple Rejection (dB)
70
60
50
40
30
20
10
0
10
100
1k
10k
Frequency (Hz)
100k
1m
D001
Figure 4. Ripple Rejection Over Frequency
10 Power Supply Recommendations
For best performance, the difference in voltage between the output and input must be between -2.5 V and -37 V.
A 1-µF solid tantalum capacitor is required on the input pin if the regulator is more than 10 cm from the power
supply filter capacitor. A 1-µF solid tantalum or 10-µF aluminum electrolytic capacitor is required on the output
pin for stability.
10
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
LM237, LM337
www.ti.com
SLVS047L – NOVEMBER 1981 – REVISED JANUARY 2015
11 Layout
11.1 Layout Guidelines
Traces on the input and output pins should be thick enough to carry 1.5 A of current without violating thermal
requirements of the device or the system. In addition, a 1-µF solid tantalum capacitor is required on the input pin
if the regulator is more than 10 cm from the power supply filter capacitor. A 1-µF solid tantalum or 10-µF
aluminum electrolytic capacitor is required on the output pin for stability.
11.2 Layout Example
1-PF tantalum or
10-PF aluminum
OUTPUT
Thicker traces for
1.5 A
INPUT
ADJUSTMENT
Thin traces for
IADJUSTMENT
(negligible)
1-PF tantalum if
>10 cm from
supply capacitor
Figure 5. Layout Diagram
12 Device and Documentation Support
12.1 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.
Table 1. Related Links
PARTS
PRODUCT FOLDER
SAMPLE & BUY
TECHNICAL
DOCUMENTS
TOOLS &
SOFTWARE
SUPPORT &
COMMUNITY
LM237
Click here
Click here
Click here
Click here
Click here
LM337
Click here
Click here
Click here
Click here
Click here
12.2 Trademarks
12.3 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.4 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Submit Documentation Feedback
Copyright © 1981–2015, Texas Instruments Incorporated
Product Folder Links: LM237 LM337
11
PACKAGE OPTION ADDENDUM
www.ti.com
4-Feb-2021
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
LM237KCSE3
ACTIVE
TO-220
KCS
3
50
RoHS & Green
SN
N / A for Pkg Type
-25 to 150
LM237
LM337KCSE3
ACTIVE
TO-220
KCS
3
50
RoHS & Green
SN
N / A for Pkg Type
0 to 125
LM337
LM337KTTR
ACTIVE
DDPAK/
TO-263
KTT
3
500
RoHS & Green
SN
Level-3-245C-168 HR
0 to 125
LM337
LM337KTTRG3
ACTIVE
DDPAK/
TO-263
KTT
3
500
RoHS & Green
SN
Level-3-245C-168 HR
0 to 125
LM337
LM337KVURG3
ACTIVE
TO-252
KVU
3
2500
RoHS & Green
SN
Level-3-260C-168 HR
0 to 125
LM337
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
工商网监
湘ICP备2023018690号
