LM325 Dual Voltage Regulator General Description Features This dual polarity tracking regulator is designed to provide balanced positive and negative output voltages at current up to 100 mA, and is set for ± 15V outputs. Input voltages up to ± 30V can be used and there is provision for adjustable current limiting. The device is available in two package types to accommodate various power requirements and temperature ranges. n n n n n n n n ± 15V tracking outputs Output current to 100 mA Output voltage balanced to within 2% Line and load regulation of 0.06% Internal thermal overload protection Standby current drain of 3 mA Externally adjustable current limit Internal current limit Schematic and Connection Diagrams Metal Can Package DS007776-3 Case connected to −VIN Top View Order Number LM325H See NS Package Number H10C DS007776-1 © 1999 National Semiconductor Corporation DS007776 www.national.com LM325 Dual Voltage Regulator June 1999 Absolute Maximum Ratings (Note 1) Output Short-Circuit Duration (Note 4) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Operating Conditions Input Voltage Forced VO+ (Min) (Note 2) Forced VO− (Max) (Note 2) Power Dissipation (Note 3) Operating Free Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec.) ± 30V −0.5V +0.5V PMAX Continuous 0˚C to +70˚C −65˚C to +150˚C 300˚C Electrical Characteristics Parameter Output Voltage Conditions Tj = 25˚C Input-Output Differential Line Regulation Line Regulation Over Temperature Range Load Regulation VO+ VO− Load Regulation Over Temperature Range VO+ VO− Min Typ Max 14.5 15 15.5 2.0 VIN = 18V to 30V, IL = 20 mA, Tj = 25˚C VIN = 18V to 30V, IL = 20 mA, IL = 0 mA to 50 mA, VIN = ± 30V, T = j 25˚C Output Voltage Balance Tj = 25˚C P ≤ PMAX, 0 ≤ IO ≤ 50 mA, 18V ≤ |VIN| ≤ 30 2.0 10 mV 20 20 mV 3.0 5.0 10 10 mV mV 4.0 7.0 20 20 mV mV ± 300 mV 14.27 15.73 ± 0.3 Temperature Stability of VO Positive Standby Current 1.75 3.0 Negative Standby Current Tj = 25˚C 3.1 5.0 Long Term Stability Thermal Resistance Junction to Case (Note 5) LM325H Junction to Ambient Junction to Ambient Junction to Ambient LM325N (Still Air) (400 Lf/min Air Flow) (Still Air) V % Tj = 25˚C Tj = 25˚C, BW = 100 − 10 kHz Tj = 25˚C Output Noise Voltage V V IL = 0 mA to 50 mA, VIN = ± 30V Output Voltage Over Temperature Range Short Circuit Current Limit Units 260 mA 150 µVrms mA mA 0.2 %/kHr 20 215 82 ˚C/W ˚C/W ˚C/W 90 ˚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 functional, but do not guarantee specific performance limits. Note 2: That voltage to which the output may be forced without damage to the device. Note 3: Unless otherwise specified these specifications apply for Tj = 0˚C to +125˚C on LM325, VIN = ± 20V, IL = 0 mA, IMAX = 100 mA, PMAX = 2.0W for the H10 Package. Note 4: If the junction temperature exceeds 150˚C, the output short circuit duration is 60 seconds. Note 5: Without a heat sink, the thermal resistance junction to ambient of the H10 Package is about 155˚C/W. With a heat sink, the effective thermal resistance can only approach the junction to case values specified, depending on the efficiency of the sink. www.national.com 2 Typical Performance Characteristics Load Regulation Standby Current Drain Regulator Dropout Voltage for Positive Regulator DS007776-12 DS007776-11 DS007776-13 Regulator Dropout Voltage for Negative Regulator Peak Output Current vs Junction Temperature DS007776-14 Load Transient Response for Positive Regulator LM325 Maximum Average Power Dissipation vs Ambient Temperature DS007776-15 Load Transient Response for Negative Regulator Line Transient Response for Positive Regulator DS007776-21 DS007776-20 3 DS007776-17 DS007776-22 www.national.com Typical Performance Characteristics Line Transient Response for Negative Regulator (Continued) Ripple Rejection Output Impedance vs Frequency DS007776-24 DS007776-25 DS007776-23 Typical Applications Basic Regulator††† DS007776-6 www.national.com 4 Typical Applications (Continued) 2.0 Amp Boosted Regulator with Current Limit DS007776-7 Note: Metal can (H) packages shown. †Solid tantalum ††Short pins 6 and 7 on dip †††RCL can be added to the basic regulator between pins 6 and 5, 1 and 2 to reduce current limit. *Required if regulator is located an appreciable distance from power supply filter. **Although no capacitor is needed for stability, it does help transient response. (If needed use 1 µF electrolytic.) ***Although no capacitor is needed for stability, it does help transient response. (If needed use 10 µF electrolytic.) Positive Current Dependent Simultaneous Current Limiting DS007776-8 5 www.national.com Typical Applications (Continued) Boosted Regulator With Foldback Current Limit DS007776-9 Positive Reg. IMAX = 2.0A ISC+ = 750 mA @ TA = 25˚C +VIN = +25V Negative Reg. IMAX = 2.0A ISC = 750 mA @ TA = 25˚C −VIN = −25V Resistor Values 125 126 R1 18 20 R2 310 180 R3 2.4k 1.35k R6 300 290 RCL 0.7 0.9 www.national.com 6 Typical Applications (Continued) Electric Shutdown DS007776-10 †Solid tantalum ††Short pins 6 and 7 on dip *Required if regulator is located an appreciable distance from power supply filter. **Although no capacitor is needed for stability, it does help transient response. (If needed use 1 µF electrolytic.) 7 www.national.com LM325 Dual Voltage Regulator Physical Dimensions inches (millimeters) unless otherwise noted Metal Can Package (H) Order Number LM325H NS Package Number H10C 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 Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] 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 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: [email protected] 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.