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LM137/LM337
3-Terminal Adjustable Negative Regulators
3-Terminal Adjustable Negative Regulators
General Description
The LM137/LM337 are adjustable 3-terminal negative volt-
age 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 opti-
mized 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.
age 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 opti-
mized 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 in-
cluding local on-card regulation, programmable-output volt-
age regulation or precision current regulation. The LM137/
LM337 are ideal complements to the LM117/LM317
adjustable positive regulators.
cluding local on-card regulation, programmable-output volt-
age 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 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
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
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
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
electrolytic are commonly used to provide improved output impedance and
rejection of transients
Comparison between SOT-223 and
D-Pak (TO-252) Packages
D-Pak (TO-252) Packages
00906731
Scale 1:1
November 2004
LM137/LM337
3-T
erminal
erminal
Adjustable
Negative
Regulators
© 2004 National Semiconductor Corporation
DS009067
www.national.com
18
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