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 Internal thermal overload protection P+ Product Enhancement tested Standard 3-lead transistor package Output is short circuit protected LM137 Series Packages and Power Capability Device LM137/337 Output voltage adjustable from -1.2V to -37V 1.5A output current guaranteed, -55C to +150C Line regulation typically 0.01%/V Load regulation typically 0.3% Typical Applications Design Load Dissipation Current 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 Features n n n n Rated Power Package Comparison between SOT-223 and D-Pak (TO-252) Packages Adjustable Negative Voltage Regulator 00906731 Scale 1:1 00906701 Full output current not available at high input-output voltages C1 = 1 F solid tantalum or 10 F aluminum electrolytic required for stability *C2 = 1 F solid tantalum is required only if regulator is more than 4" from power-supply filter capacitor Output capacitors in the range of 1 F to 1000 F of aluminum or tantalum electrolytic are commonly used to provide improved output impedance and rejection of transients (c) 2001 National Semiconductor Corporation DS009067 www.national.com LM137/LM337 3-Terminal Adjustable Negative Regulators November 2001 LM137/LM337 Absolute Maximum Ratings (Notes 1, 4) Internally Limited Input-Output Voltage Differential 40V Operating Junction Temperature Range LM137 -55C to +150C 0C to +125C LM337I -40C to +125C Storage Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Power Dissipation LM337 -65C to +150C Lead Temperature (Soldering, 10 sec.) 300C Plastic Package (Soldering, 4 sec.) 260C ESD Rating 2k Volts Electrical Characteristics (Note 1) Parameter Conditions LM137 Min Line Regulation Tj = 25C, 3V |VIN - VOUT| 40V Load Regulation Tj = 25C, 10 mA IOUT IMAX Thermal Regulation Tj = 25C, 10 ms Pulse LM337 Typ Max 0.01 0.02 Min Units Typ Max 0.01 0.04 %/V (Note 2) IL = 10 mA Adjustment Pin Current Adjustment Pin Current Charge 10 mA IL IMAX 0.3 0.5 0.3 1.0 % 0.002 0.02 0.003 0.04 %/W 65 100 65 100 A 2 5 2 5 A 3.0V |VIN - VOUT| 40V, TA = 25C Reference Voltage Tj = 25C (Note 3) -1.225 -1.250 -1.275 -1.213 -1.250 -1.287 V 3V |VIN - VOUT| 40V, (Note 3) -1.200 -1.250 -1.300 -1.200 -1.250 -1.300 V 10 mA IOUT IMAX, P PMAX Line Regulation 3V |VIN - VOUT| 40V, (Note 2) 0.02 0.05 0.02 0.07 Load Regulation 10 mA IOUT IMAX, (Note 2) 0.3 1 0.3 1.5 Temperature Stability TMIN Tj TMAX 0.6 |VIN - VOUT| 40V 2.5 5 2.5 10 mA |VIN - VOUT| 10V 1.2 3 1.5 6 mA Minimum Load Current Current Limit 0.6 %/V % % |VIN - 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 K, MP and T Package 0.24 0.4 0.15 0.4 H Package 0.15 0.17 0.10 |VIN - VOUT| = 40V, Tj = 25C RMS Output Noise, % of VOUT Ripple Rejection Ratio Tj = 25C, 10 Hz f 10 kHz 0.003 VOUT = -10V, f = 120 Hz 60 CADJ = 10 F 66 77 66 A 0.17 A 0.003 % 60 dB 77 dB Long-Term Stability Tj = 125C, 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 Thermal Resistance, Junction to Ambient (No Heat Sink) 4 C/W H Package 140 140 C/W K Package 35 35 C/W 50 170 C/W C/W T Package MP Package Note 1: Unless otherwise specified, these specifications apply -55C Tj +150C for the LM137, 0C Tj +125C for the LM337; VIN - VOUT = 5V; and IOUT = 0.1A for the TO-39 package and IOUT = 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. IMAX 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 18" below the base of the TO-3 and TO-39 packages. www.national.com 2 LM137/LM337 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 00906702 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 VOUT, 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, VOUT = -10V VIN - VOUT = -40V IIL = 0A 0.25A 0A Vertical sensitivity, 5 mV/div FIGURE 1. 3 www.national.com LM137/LM337 Thermal Regulation (Continued) In Figure 1, a typical LM137's output drifts only 3 mV (or 0.03% of VOUT = -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 shows a 3 mV step 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). 00906704 LM137, VOUT = -10V VIN - VOUT = -40V IL = 0A 0.25A 0A Horizontal sensitivity, 20 ms/div FIGURE 2. Connection Diagrams TO-3 Metal Can Package TO-220 Plastic Package 00906705 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 00906707 Front View Order Number LM337T See NS Package Number T03B 3-Lead SOT-223 00906706 Bottom View Order Number LM137H, LM137H/883 or LM337H LM137HPQML and LM137HPQMLV(Note 5) See NS Package Number H03A 00906734 Front View Order Number LM337IMP Package Marked N02ASee NS Package Number MA04A Case Is Input Note 5: See STD Mil DWG 5962P99517 for Radiation Tolerant Devices www.national.com 4 LM137/LM337 Application Hints Typical Applications When a value for (H-A) is found using the equation shown, a heatsink must be selected that has a value that is less than or equal to this number. Adjustable Lab Voltage Regulator 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 (J-A) of 75C/W for 1 ounce copper and 51C/W for 2 ounce copper and a maximum junction temperature of 125C. 00906709 Full output current not available at high input-output voltages *The 10 F capacitors are optional to improve ripple rejection Current Regulator 00906732 FIGURE 3. (J-A) vs Copper (2 ounce) Area for the SOT-223 Package 00906711 Negative Regulator with Protection Diodes 00906733 FIGURE 4. Maximum Power Dissipation vs. TAMB for the SOT-223 Package Please see AN1028 for power enhancement techniques to be used with the SOT-223 package. 00906713 *When CL is larger than 20 F, D1 protects the LM137 in case the input supply is shorted **When C2 is larger than 10 F and -VOUT is larger than -25V, D2 protects the LM137 in case the output is shorted 5 www.national.com LM137/LM337 Typical Applications (Continued) High Stability -10V Regulator -5.2V Regulator with Electronic Shutdown* 00906714 00906710 *Minimum output . -1.3V when control input is low Adjustable Current Regulator 00906712 www.national.com 6 LM137/LM337 Typical Performance Characteristics (K Steel and T Packages) Load Regulation Current Limit 00906716 00906717 Adjustment Current Dropout Voltage 00906718 00906719 Temperature Stability Minimum Operating Current 00906720 00906721 7 www.national.com LM137/LM337 Typical Performance Characteristics (K Steel and T Packages) (Continued) Ripple Rejection Ripple Rejection 00906722 00906723 Ripple Rejection Output Impedance 00906724 00906725 Line Transient Response Load Transient Response 00906726 www.national.com 00906727 8 LM137/LM337 Physical Dimensions inches (millimeters) unless otherwise noted Metal Can Package (H) Order Number LM137H, LM137H/883 or LM337H NS Package Number H03A 9 www.national.com LM137/LM337 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Metal Can Package (K) Order Number LM337K STEEL NS Package Number K02A Mil-Aero Metal Can Package (K) Order Number LM137K/883 NS Package Number K02C www.national.com 10 LM137/LM337 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 3-Lead SOT-223 Package Order Number LM337IMP NS Package Number M04A 11 www.national.com LM137/LM337 3-Terminal Adjustable Negative Regulators Physical Dimensions inches (millimeters) unless otherwise noted (Continued) TO-220 Plastic Package (T) Order Number LM337T NS Package Number T03B LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Francais Tel: +33 (0) 1 41 91 8790 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. National P/N LM337 - 3-Terminal Adjustable Negative Regulator See Wireless Products Products > Analog - Regulators > Linear Regulators - Standard/NPN > Negative Voltage - Adjustable > LM337 LM337 Product Folder 3-Terminal Adjustable Negative Regulator Generic P/N 337 General Description Features Package & Models Datasheet Parametric Table Samples & Pricing Application Notes Parametric Table Multiple Output Capability No Input Voltage, max (Volt) -4.20 On/Off Pin No Output Current, max 1500 mA Error Flag - Watchdog - Input Voltage, min (Volt) -40 Output Voltage, min (Volt) -37 Output Voltage, max (Volt) -1.20 Datasheet Size in Date Kbytes Title LM137 LM337 3-Terminal Adjustable Negative Regulators View Online Download 10421 Dec- View Online Kbytes 01 LM137 LM337 3-Terminal Adjustable Negative Regulators (JAPANESE) 185 Kbytes View Online Download Download Receive via Email Receive via Email Receive via Email If you have trouble printing or viewing PDF file(s), see Printing Problems. Package Availability, Models, Samples & Pricing Part Number Package Status Type Pins MSL LM337IMP SOT223 4 MSL LM337IMPX SOT223 4 MSL Samples & Electronic Orders SPICE IBIS Models Budgetary Pricing Std Pack Qty $US each Size 1K+ $0.4400 reel of 1000 2T N02A 1K+ $0.4400 reel of 2000 2T N02A Samples Full production N/A N/A Full production N/A N/A Buy Now Buy Now Package Marking file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM337.html (1 of 3) [Aug-09-2002 11:58:56 AM] National P/N LM337 - 3-Terminal Adjustable Negative Regulator Buy Now 1K+ $0.3550 rail of 45 [logo]UZ2T LM337T P+ Buy Now 1K+ $1.6800 bag of 500 [logo]Z2T LM337H N/A Buy Now 250+ $2.4000 tray of 50 [logo]Z2T LM337K STEEL N/A Samples tray of N/A - wafer jar of N/A - LM337T TO 220 3 MSL Full production N/A N/A LM337H TO-39 3 MSL Full production N/A N/A LM337K STEEL TO-3 3 MSL Full production N/A Die Full production N/A Wafer Full production LM337K MDC LM337K MWC N/A N/A 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, programmableoutput voltage regulation or precision current regulation. The LM137/LM337 are ideal complements to the LM117/LM317 adjustable positive regulators. Features Output voltage adjustable from -1.2V to -37V 1.5A output current guaranteed, -55C to +150C Line regulation typically 0.01%/V Load regulation typically 0.3% Excellent thermal regulation, 0.002%/W 77 dB ripple rejection Excellent rejection of thermal transients 50 ppm/C temperature coefficient Temperature-independent current limit Internal thermal overload protection P+ Product Enhancement tested Standard 3-lead transistor package Output is short circuit protected LM137 Series Packages and Power Capability Device LM137/337 Package TO-3 (K) Rated Design Power Load Dissipation Current 20W 1.5A file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM337.html (2 of 3) [Aug-09-2002 11:58:56 AM] National P/N LM337 - 3-Terminal Adjustable Negative Regulator TO-39 (H) 2W 0.5A LM337 TO-220 (T) 15W 1.5A LM337 SOT-223 (MP) 2W 1A Application Notes Title Size in Kbytes Date LB-46: A New Production Technique for Trimming Voltage Regulators 91 Kbytes View Online Download Receive via Email 28-Jun-96 View Online Download Receive via Email If you have trouble printing or viewing PDF file(s), see Printing Problems. [Information as of 5-Aug-2002] Search Design Purchasing Quality Company Home About Languages . Website Guide . About "Cookies" . National is QS 9000 Certified . Privacy/Security Statement . Contact Us . Site Terms & Conditions of Use . Copyright 2002 (c) National Semiconductor Corporation . My Preferences . Feedback file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM337.html (3 of 3) [Aug-09-2002 11:58:56 AM] National P/N LM137 - 3-Terminal Adjustable Negative Regulator See A/D Converters Products Products > Analog - Regulators > Linear Regulators - Standard/NPN > Negative Voltage - Adjustable > LM137 LM137 Product Folder 3-Terminal Adjustable Negative Regulator Generic P/N 137 General Description Features Package & Models Datasheet Parametric Table Samples & Pricing Application Notes Parametric Table Multiple Output Capability No Input Voltage, max (Volt) -4.20 On/Off Pin No Output Current, max 1500 mA Error Flag - Watchdog - Input Voltage, min (Volt) -40 Output Voltage, min (Volt) -37 Output Voltage, max (Volt) -1.20 Datasheet Title Size in Kbytes Date LM137 LM337 3-Terminal Adjustable Negative Regulators 421 Kbytes View Online Download Receive via Email 10-Dec-01 View Online Download Receive via Email LM137 Mil-Aero (DESC) Datasheet 12 Kbytes MDLM137-H View Online Download Receive via Email LM137 Mil-Aero (DESC) Datasheet 12 Kbytes MDLM137-K View Online Download Receive via Email LM137 Mil-Aero (JAN) Datasheet MJLM137-H 104 Kbytes View Online Download Receive via Email LM137 Mil-Aero (JAN) Datasheet MJLM137-K 111 Kbytes View Online Download Receive via Email LM137 Mil-Aero Datasheet MNLM137-K 110 Kbytes View Online Download Receive via Email LM137 Mil-Aero Datasheet MNLM137-WG 126 Kbytes View Online Download Receive via Email LM137 Mil-Aero Datasheet MNLM137-X 197 Kbytes View Online Download Receive via Email LM137 Mil-Aero Datasheet MNLM137A-H 15 Kbytes View Online Download Receive via Email LM137 Mil-Aero Datasheet MRLM137-K-RH 113 Kbytes View Online Download Receive via Email If you have trouble printing or viewing PDF file(s), see Printing Problems. Package Availability, Models, Samples & Pricing Part Number Package Status Models Samples & Electronic Budgetary Pricing Std Pack Package file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM137.html (1 of 4) [Aug-09-2002 11:58:59 AM] National P/N LM137 - 3-Terminal Adjustable Negative Regulator Type Pins MSL LM137H TO-39 3 MSL LM137H-MPR TO-39 3 MSL LM137AH/883 TO-39 3 MSL 7703403XA TO-39 3 LM137H/883 TO-39 7703403YA LM137K/883 SPICE IBIS N/A N/A N/A N/A Full production N/A N/A MSL Full production N/A N/A 3 MSL Full production N/A N/A TO-3 2 MSL Full production N/A N/A TO-3 2 MSL Full production N/A N/A LM137WG/883 Ceramic SOIC 16 MSL Full production N/A LM137WG-MPR Ceramic SOIC 16 MSL Preliminary N/A JM38510/11803BX TO-39 JM38510/11804BY 3 TO-3 JM38510/11803SX TO-39 LM137KPQMLV JM38510/11804SY 59629951701VZA TO-3 Full production N/A 250+ $US each Size $8.4000 Buy Now $7.8000 tray of 20 [logo] ZS4A$E QM 27014 7703403XA Buy Now 50+ $11.6000 tray of 20 [logo] ZS4A$E LM137H/883QM 50+ $9.0000 tray of 50 [logo]ZS4A 7703403YA 27014 QM$E 50+ $9.0000 tray of 50 [logo]ZS4A LM137K/883 QM $E N/A tray of N/A [logo]ZS4A$E LM137WG/883Q N/A tray of N/A [logo]ZS4A$E LM137WGMPR PROTO N/A $29.9000 [logo] ZS4A tray 27014 QM of JM38510/11803BXA 20 $E $20.0000 tray of 50 Buy Now Buy Now 50+ 3 MSL Full production N/A N/A 50+ $194.0000 16 MSL Full production N/A [logo]ZS4A$E LM137H-MPR 50+ 50+ MSL tray of N/A [logo] ZS4A$E LM137AH/883QM N/A N/A [logo]Z2T LM137HP+ tray of 20 N/A Full production bag of 500 $14.0000 Full production MSL Marking 50+ Buy Now MSL 2 Ceramic SOIC Full production Buy Now Qty 2 2 TO-3 MSL Full production Orders [logo]ZS4A JM38510/ 11804BYA 27014 QS $E tray [logo] ZS4A$E of 27014 Q 20 JM38510/11803SXA N/A tray of N/A [logo]ZS4A LM137KPQMLV 5962P99517 02VYA $E N/A tray 50+ $200.0000 of 50 [logo]ZS4A JM38510/ 11804SYA 27014 Q$E tray 50+ $199.0000 of 42 [logo]ZS4A$E LM137WGQMLV 5962 9951701VZA Full production N/A N/A LM137K MDA Die Full production N/A N/A Samples tray of N/A - LM137KG MDA Die Full production N/A N/A Samples tray of N/A - LM137H MD8 Die Full production N/A N/A Samples tray of N/A - file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM137.html (2 of 4) [Aug-09-2002 11:58:59 AM] National P/N LM137 - 3-Terminal Adjustable Negative Regulator tray of N/A - tray of 100 - N/A wafer jar of N/A - N/A wafer jar of N/A - LM137K MDS Die Full production N/A N/A LM137H MDS Die Full production N/A N/A LM137KG MWA Wafer LM137H MW8 Wafer Full production Full production N/A N/A 50+ $42.0000 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, programmableoutput voltage regulation or precision current regulation. The LM137/LM337 are ideal complements to the LM117/LM317 adjustable positive regulators. Features Output voltage adjustable from -1.2V to -37V 1.5A output current guaranteed, -55C to +150C Line regulation typically 0.01%/V Load regulation typically 0.3% Excellent thermal regulation, 0.002%/W 77 dB ripple rejection Excellent rejection of thermal transients 50 ppm/C temperature coefficient Temperature-independent current limit Internal thermal overload protection P+ Product Enhancement tested Standard 3-lead transistor package Output is short circuit protected LM137 Series Packages and Power Capability Rated Design Power Load Dissipation Current 20W 1.5A TO-39 (H) 2W 0.5A LM337 TO-220 (T) 15W 1.5A LM337 SOT-223 (MP) 2W 1A Device LM137/337 Package TO-3 (K) file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM137.html (3 of 4) [Aug-09-2002 11:58:59 AM] National P/N LM137 - 3-Terminal Adjustable Negative Regulator Application Notes Title Size in Kbytes Date LB-46: A New Production Technique for Trimming Voltage Regulators 91 Kbytes 28-Jun-96 View Online Download Receive via Email AN-182: Inproving Power Supply 76 Kbytes Reliability with IC Power Regulators 4-Nov-95 View Online Download Receive via Email View Online Download Receive via Email If you have trouble printing or viewing PDF file(s), see Printing Problems. [Information as of 5-Aug-2002] Search Design Purchasing Quality Company Home About Languages . Website Guide . About "Cookies" . National is QS 9000 Certified . Privacy/Security Statement . Contact Us . Site Terms & Conditions of Use . Copyright 2002 (c) National Semiconductor Corporation . My Preferences . Feedback file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM137.html (4 of 4) [Aug-09-2002 11:58:59 AM]