LM137| Datasheet

Datasheet preview, take a look at Datasheets before downloading (Data Sheet is available on manufacturer site)

LM137/LM337 3-Terminal Adjustable Negative Regulators

November 2004

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. n n n n n n n n n Excellent thermal regulation, 0.002%/W 77 dB ripple rejection Excellent rejection of thermal transients 50 ppm/ C temperature coefficient Temperature-independent current limit Inter
nal thermal overload protection P+ Product Enhancement tested Standard 3-lead transistor package Output is short circuit protected LM137 Series Packages and Power Capability Rated Device LM137/337 Package TO-3 (K) TO-39 (H) LM337 LM337 TO-220 (T) SOT-223 (MP) Power Dissipation 20W 2W 15W 2W Design Load Current 1.5A 0.5A 1.5A 1A

Features
n n n n Output voltage adjustable from -1.2V to -37V 1.5A output current guaranteed, -55 C to +150 C Line regulation typically 0.01%/V Load regulation typically 0.3%

Typical Applications
Adjustable Negative Voltage Regulator

Comparison between SOT-223 and D-Pak (TO-252) Packages

00906731

Scale 1:1

00906701

Full output current not available at high input-output voltages

C1 = 1 uF solid tantalum or 10 uF aluminum electrolytic required for stability

*C2 = 1 uF solid tantalum is required only if regulator is more than 4" from power-supply filter capacitor Output capacitors in the range of 1 uF to 1000 uF of aluminum or tantalum electrolytic are commonly used to provide improved output impedance and rejection of transients

2004 National Semiconductor Corporation

DS009067

www.national.com