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LM138 NSC | Alldatasheet

Document overview

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Technical content

Features

n Guaranteed 7A peak output current n Guaranteed 5A output current n Adjustable output down to 1.2V n Guaranteed thermal regulation n Current limit constant with temperature n P+ Product Enhancement tested n Output is short-circuit protected

Applications

n Adjustable power supplies n Constant current regulators n Battery chargers Connection Diagrams(See Physical Dimension section for further information) (TO-3 STEEL) Metal Can Package DS009060-30 Bottom View Order Number LM138K STEEL or LM338K STEEL See NS Package Number K02A (TO-220) Plastic Package DS009060-31 Front View Order Number LM338T See NS Package Number T03B May 1998 LM138/LM338 5-Amp Adjustable Regulators © 1999 National Semiconductor Corporation DS009060 www.national.com

Absolute Maximum Ratings(Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. (Note 4) Power Dissipation Internally limited Input/Output Voltage Differential +40V, −0.3V Storage Temperature −65˚C to +150˚C Lead Temperature Metal Package (Soldering, 10 seconds) Plastic Package (Soldering, 4 seconds) 300˚C 260˚C ESD Tolerance TBD Operating Temperature Range LM138 −55˚C ≤ TJ ≤ +150˚C LM338 0˚C ≤ TJ ≤ +125˚C

Electrical Characteristics

Specifications with standard type face are for TJ = 25˚C, and those withboldface typeapply overfull Operating Tempera- ture Range.Unless otherwise specified, VIN −V OUT = 5V; and IOUT = 10 mA. (Note 2) Symbol Parameter Conditions LM138 Units Min Typ Max VREF Reference Voltage 3V ≤ (VIN −V OUT )≤ 35V, 1.19 1.24 1.29 V 10 mA ≤ IOUT ≤ 5A, P≤ 50W VRLINE Line Regulation 3V ≤ (VIN −V OUT )≤ 35V (Note 3) 0.005 0.01 % /V 0.02 0.04 % /V VRLOAD Load Regulation 10 mA ≤ IOUT ≤ 5A (Note 3) 0.1 0.3 % 0.3 0.6 % Thermal Regulation 20 ms Pulse 0.002 0.01 % /W IADJ Adjustment Pin Current 45 100 µA ΔIADJ Adjustment Pin Current Change 10 mA ≤ IOUT ≤ 5A, 0.2 5 µA 3V ≤ (VIN −V OUT )≤ 35V ΔVR/T Temperature Stability T MIN ≤ TJ ≤ TMAX 1 % ILOAD (Min) Minimum Load Current V IN −V OUT = 35V 3.5 5 mA ICL Current Limit V IN −V OUT ≤ 10V DC 58 A 0.5 ms Peak 71 2 A VIN −V OUT = 30V 1 1 A VN RMS Output Noise,% of VOUT 10 Hz ≤ f≤ 10 kHz 0.003 % Ripple Rejection Ratio V OUT = 10V, f= 120 Hz, CADJ = 0µ F 60 dB VOUT = 10V, f= 120 Hz, CADJ = 10 µF 60 75 dB Long-Term Stability T J = 125˚C, 1000 Hrs 0.3 1 % θJC Thermal Resistance, K Package 1 ˚C/W Junction to Case θJA Thermal Resistance, Junction to K Package 35 ˚C/W Ambient (No Heat Sink) Symbol Parameter Conditions LM338 Units Min Typ Max VREF Reference Voltage 3V ≤ (VIN −V OUT )≤ 35V, 1.19 1.24 1.29 V 10 mA ≤ IOUT ≤ 5A, P≤ 50W VRLINE Line Regulation 3V ≤ (VIN −V OUT )≤ 35V (Note 3) 0.005 0.03 % /V 0.02 0.06 % /V VRLOAD Load Regulation 10 mA ≤ IOUT ≤ 5A (Note 3) 0.1 0.5 % 0.3 1 % Thermal Regulation 20 ms Pulse 0.002 0.02 % /W IADJ Adjustment Pin Current 45 100 µA ΔIADJ Adjustment Pin Current Change 10 mA ≤ IOUT ≤ 5A, 3V ≤ (VIN −V OUT )≤ 35V 0.2 5 µA www.national.com 2

Electrical Characteristics(Continued) Symbol Parameter Conditions LM338 Units Min Typ Max ΔVR/T Temperature Stability T MIN ≤ TJ ≤ TMAX 1 % ILOAD (Min) Minimum Load Current V IN −V OUT = 35V 3.5 10 mA ICL Current Limit V IN −V OUT ≤ 10V DC 58 A 0.5 ms Peak 71 2 A VIN −V OUT = 30V 1 A VN RMS Output Noise,% of VOUT 10 Hz ≤ f≤ 10 kHz 0.003 % Ripple Rejection Ratio V OUT = 10V, f= 120 Hz, CADJ = 0µ F 60 dB VOUT = 10V, f= 120 Hz, CADJ = 10 µF 60 75 dB Long-Term Stability T J = 125˚C, 1000 hrs 0.3 1 % θJC Thermal Resistance K Package 1 ˚C/W Junction to Case T Package 4 ˚C/W θJA Thermal Resistance, Junction to K Package 35 ˚C/W Ambient (No Heat Sink) T Package 50 ˚C/W Note 1:Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is in- tended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2:These specifications are applicable for power dissipations up to 50W for the TO-3 (K) package and 25W for the TO-220 (T) package. Power dissipation is guaranteed at these values up to 15V input-output differential. Above 15V differential, power dissipation will be limited by internal protection circuitry. All limits (i.e., the numbers in the Min. and Max. columns) are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 3:Regulation is measured at a constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effectsare covered under the specifications for thermal regulation. Note 4:Refer to RETS138K drawing for military specifications of LM138K. Typical Performance Characteristics Current Limit DS009060-32 Current Limit DS009060-33 Current Limit DS009060-34 Load Regulation DS009060-35 Dropout Voltage DS009060-36 Adjustment Current DS009060-37 www.national.com3

Typical Performance Characteristics(Continued) Application Hints In operation, the LM138 develops a nominal 1.25V reference voltage, VREF , between the output and adjustment terminal. The reference voltage is impressed across program resistor R1 and, since the voltage is constant, a constant current I then flows through the output set resistor R2, giving an out- put voltage of Temperature Stability DS009060-38 Output Impedance DS009060-39 Minimum Operating Current DS009060-40 Ripple Rejection DS009060-41 Ripple Rejection DS009060-42 Ripple Rejection DS009060-43 Line Transient Response DS009060-44 Load Transient Response DS009060-45 www.national.com 4

FIGURE 3. Regulator with Protection Diodes

Regulator and Voltage Reference DS009060-3 1.2V–25V Adjustable Regulator DS009060-1 Temperature Controller DS009060-10 Full output current not available at high input-output voltages †Optional — improves transient response. 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. *Needed if device is more than 6 inches from filter capacitors. **R1 = 240Ω for LM138. R1, R2 as an assembly can be ordered from Bourns: MIL part no. 7105A-AT2-502 COMM part no. 7105A-AT7-502 www.national.com7

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Precision Power Regulator with Low Temperature Coefficient DS009060-12 * Adjust for 3.75 across R1 Slow Turn-On 15V Regulator DS009060-13 Adjustable Regulator with Improved Ripple Rejection DS009060-14 †Solid tantalum *Discharges C1 if output is shorted to ground **R1 = 240Ω for LM138 High Stability 10V Regulator DS009060-15 Digitally Selected Outputs DS009060-16 *Sets maximum VOUT **R1 = 240Ω for LM138 www.national.com9

Typical Applications(Continued) 15A Regulator DS009060-17 * Minimum load — 100 mA 5V Logic Regulator with Electronic Shutdown DS009060-18 Minimum output≈ 1.2V Light Controller DS009060-11 www.national.com 10

Typical Applications(Continued) 0 to 22V Regulator DS009060-19 *R 1 = 240Ω ,R 2= 5k for LM138 Full output current not available at high input-output voltages 12V Battery Charger DS009060-20 www.national.com11

Typical Applications(Continued) Adjustable Current Regulator DS009060-21 Precision Current Limiter DS009060-22 5A Current Regulator DS009060-23 Tracking Preregulator DS009060-24 Adjusting Multiple On-Card Regulators with Single Control* DS009060-25 † Minimum load — 10 mA * All outputs within±100 mV www.national.com 12

Typical Applications(Continued) Power Amplifier DS009060-27 AV = 1, RF = 10k, CF = 100 pF AV = 10, RF = 100k, CF = 10 pF Bandwidth≥ 100 kHz Distortion≤ 0.1% Simple 12V Battery Charger DS009060-28 Use of RS allows low charging rates with fully charged battery. **The 1000 µF is recommended to filter out input transients www.national.com13

Typical Applications(Continued) Adjustable 15A Regulator DS009060-26 Current Limited 6V Charger DS009060-29 * Set max charge current to 3A ** THE 1000 µF is recommended to filter out input transients. 10A Regulator DS009060-2 * Minimum load — 100 mA www.national.com 14

Physical Dimensionsinches (millimeters) unless otherwise noted

2 Lead TO-3 Metal Can Package (K)

Order Number LM138K or LM338K STEEL

3 Lead Molded TO-220 (T)

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NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE- VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMI- CONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or sys- tems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose fail- ure 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. 2. A critical component is any component of a life support device or system whose failure to perform can be rea- sonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: sea.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 LM138/LM338 5-Amp Adjustable Regulators 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.