NSC LM337MP Datasheet
LM137/LM337
3-Terminal Adjustable Negative Regulators
General Description
The LM137/LM337 are adjustable 3-terminal negative voltage regulators capable 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
Adjustable Negative Voltage Regulator
00906701
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
Comparison between SOT-223 and
D-Pak (TO-252) Packages
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Scale 1:1
November 2001
LM137/LM337 3-Terminal Adjustable Negative Regulators
© 2001 National Semiconductor Corporation DS009067 www.national.com
Absolute Maximum Ratings (Notes 1,
4)
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
LM137 −55˚C to +150˚C
LM337 0˚C to +125˚C
LM337I −40˚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 ≤ |VIN−V
OUT
| ≤ 40V 0.01 0.02 0.01 0.04 %/V
(Note 2) I
L
=10mA
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, Tj= 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
Tj= 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
=10µF 6677 6677 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. Although power 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 1.5A for the TO-3,
SOT-223 and TO-220 packages, and 0.2A for 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
covered under the specification for thermal regulation. Load regulation is measured on the output pin at a point
1
⁄8" below the base of the TO-3 and TO-39 packages.
LM137/LM337
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Electrical Characteristics (Note 1) (Continued)
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.
Schematic Diagram
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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 IC regulator, this gradient can be especially severe since power dissipation is large. 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 within 5 ms to 50 ms after a change in
power dissipation. Thermal regulation depends on IC layout
as well as electrical design. The thermal regulation of a
voltage 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.
00906703
LM137, V
OUT
= −10V
V
IN−VOUT
= −40V
I
IL
=0A→0.25A→0A
Vertical sensitivity, 5 mV/div
FIGURE 1.
LM137/LM337
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Thermal Regulation (Continued)
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 well inside the specification
limit of 0.02%/W x 10W = 0.2% max. When the 10W 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 the thermal regulation
error.In
Figure 2
, when the 10W pulse is applied for 100 ms,
the output drifts only slightly beyond the drift in the first
10 ms, and the thermal error stays well within 0.1% (10 mV).
Connection Diagrams
TO-3
Metal Can Package
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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
Case is Input
TO-39
Metal Can Package
00906706
Bottom View
Order Number LM137H, LM137H/883 or LM337H
LM137HPQML and LM137HPQMLV(Note 5)
See NS Package Number H03A
Case Is Input
Note 5: See STD Mil DWG 5962P99517 for Radiation Tolerant Devices
TO-220
Plastic Package
00906707
Front View
Order Number LM337T
See NS Package Number T03B
3-Lead SOT-223
00906734
Front View
Order Number LM337IMP
Package Marked N02ASee NS Package Number MA04A
00906704
LM137, V
OUT
= −10V
V
IN−VOUT
= −40V
I
L
=0A→0.25A→0A
Horizontal sensitivity, 20 ms/div
FIGURE 2.
LM137/LM337
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