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
DS009067-1
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
DS009067-31
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.
www.national.com 2
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).
DS009067-2
DS009067-3
LM137, V
OUT
=
−10V
V
IN−VOUT
=
−40V
I
IL
=
0A→0.25A→0A
Vertical sensitivity, 5 mV/div
FIGURE 1.
www.national.com3
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.
DS009067-4
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
DS009067-5
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
DS009067-6
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
DS009067-7
Front View
Order Number LM337T
See NS Package Number T03B
3-Lead SOT-223
DS009067-34
Front View
Order Number LM337IMP
Package Marked N02ASee NS Package Number MA04A
www.national.com 4
Loading...