Order this document by LM337/D The LM337 is an adjustable 3–terminal negative voltage regulator capable of supplying in excess of 1.5 A over an output voltage range of –1.2 V to – 37 V. This voltage regulator is exceptionally easy to use and requires only two external resistors to set the output voltage. Further, it employs internal current limiting, thermal shutdown and safe area compensation, making it essentially blow–out proof. The LM337 serves a wide variety of applications including local, on card regulation. This device can also be used to make a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the LM337 can be used as a precision current regulator. • Output Current in Excess of 1.5 A • • • • • • • THREE–TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR SEMICONDUCTOR TECHNICAL DATA Output Adjustable between –1.2 V and – 37 V Internal Thermal Overload Protection Internal Short Circuit Current Limiting Constant with Temperature T SUFFIX PLASTIC PACKAGE CASE 221A Output Transistor Safe–Area Compensation Floating Operation for High Voltage Applications Eliminates Stocking many Fixed Voltages Available in Surface Mount D2PAK and Standard 3–Lead Transistor Package Heatsink surface connected to Pin 2. 1 2 3 Pin 1. Adjust 2. Vin 3. Vout Standard Application IPROG Cin* 1.0 µF R2 + CO** 1.0 µF R1 120 D2T SUFFIX PLASTIC PACKAGE CASE 936 (D2PAK) + 1 2 3 IAdj Vin –Vin LM337 Heatsink surface (shown as terminal 4 in case outline drawing) is connected to Pin 2. Vout –Vout ORDERING INFORMATION * Cin is required if regulator is located more than 4 inches from power supply filter. * A 1.0 µF solid tantalum or 10 µF aluminum electrolytic is recommended. ǒ Ǔ ** CO is necessary for stability. A 1.0 µF solid tantalum or 10 µF aluminum electrolytic ** is recommeded. V out + –1.25 V 1 ) R R2 1 Device Operating Temperature Range Surface Mount LM337BD2T LM337BT LM337D2T LM337T TJ = – 40° to +125°C TJ = 0° to +125°C Motorola, Inc. 1996 MOTOROLA ANALOG IC DEVICE DATA Package Insertion Mount Surface Mount Insertion Mount Rev 1 1 LM337 MAXIMUM RATINGS Rating Input–Output Voltage Differential Symbol Value Unit VI–VO 40 Vdc PD θJA θJC Internally Limited 65 5.0 W °C/W °C/W PD θJA θJC Internally Limited 70 5.0 W °C/W °C/W TJ – 40 to +125 °C Tstg – 65 to +150 °C Power Dissipation Case 221A TA = +25°C Thermal Resistance, Junction–to–Ambient Thermal Resistance, Junction–to–Case Case 936 (D2PAK) TA = +25°C Thermal Resistance, Junction–to–Ambient Thermal Resistance, Junction–to–Case Operating Junction Temperature Range Storage Temperature Range ELECTRICAL CHARACTERISTICS (|VI–VO| = 5.0 V; IO = 0.5 A for T package; TJ = Tlow to Thigh [Note 1]; Imax and Pmax [Note 2].) Characteristics Figure Symbol Min Typ Max Unit – 0.01 0.04 %/V – – 15 0.3 50 1.0 mV % VO Regtherm – 0.003 0.04 % VO/W Line Regulation (Note 3), TA = +25°C, 3.0 V ≤ |VI–VO| ≤ 40 V 1 Regline Load Regulation (Note 3), TA = +25°C, 10 mA ≤ IO ≤ Imax |VO| ≤ 5.0 V |VO| ≥ 5.0 V 2 Regload Thermal Regulation, TA = +25°C (Note 6), 10 ms Pulse 3 IAdj – 65 100 µA Adjustment Pin Current Change, 2.5 V ≤ |VI–VO| ≤ 40 V, 10 mA ≤ IL ≤ Imax, PD ≤ Pmax, TA = +25°C 1, 2 ∆IAdj – 2.0 5.0 µA Reference Voltage, TA = +25°C, 3.0 V ≤ |VI–VO| ≤ 40 V, 10 mA ≤ IO ≤ Imax, PD ≤ Pmax, TJ = Tlow to Thigh 3 Vref –1.213 –1.20 –1.250 –1.25 –1.287 –1.30 V Line Regulation (Note 3), 3.0 V ≤ |VI–VO| ≤ 40 V 1 Regline – 0.02 0.07 %/V Load Regulation (Note 3), 10 mA ≤ IO ≤ Imax |VO| ≤ 5.0 V |VO| ≥ 5.0 V 2 Regload – – 20 0.3 70 1.5 mV % VO Temperature Stability (Tlow ≤ TJ ≤ Thigh) 3 TS – 0.6 – % VO Minimum Load Current to Maintain Regulation (|VI–VO| ≤ 10 V) (|VI–VO| ≤ 40 V) 3 ILmin – – 1.5 2.5 6.0 10 Maximum Output Current |VI–VO| ≤ 15 V, PD ≤ Pmax, T Package |VI–VO| ≤ 40 V, PD ≤ Pmax, TJ = +25°C, T Package 3 – – 1.5 0.15 2.2 0.4 – 0.003 – – 66 60 77 – – S – 0.3 1.0 %/1.0 k Hrs. RθJC – 4.0 – °C/W Adjustment Pin Current RMS Noise, % of VO, TA = +25°C, 10 Hz ≤ f ≤ 10 kHz 4 Long–Term Stability, TJ = Thigh (Note 5), TA = +25°C for Endpoint Measurements 3 Thermal Resistance Junction–to–Case, T Package Imax N Ripple Rejection, VO = –10 V, f = 120 Hz (Note 4) Without CAdj CAdj = 10 µF mA A RR % VO dB NOTES: 1. Tlow to Thigh = 0° to +125°C, for LM337T, D2T. Tlow to Thigh = – 40° to +125°C, for LM337BT, BD2T. 2. Imax = 1.5 A, Pmax = 20 W 3. Load and line regulation are specified at constant junction temperature. Change in VO because of heating effects is covered under the Thermal Regulation specification. Pulse testing with a low duty cycle is used. 4. CAdj, when used, is connected between the adjustment pin and ground. 5. Since Long Term Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot. 6. Power dissipation within an IC voltage regulator produces a temperature gradient on the die, affecting individual IC components on the die. These effects can be minimized by proper integrated circuit design and layout techniques. Thermal Regulation is the effect of these temperature gradients on the output voltage and is expressed in percentage of output change per watt of power change in a specified time. 2 MOTOROLA ANALOG IC DEVICE DATA LM337 Representative Schematic Diagram Adjust 60 100 2.0k 2.5k 810 21k Vout 10k 800 15pF 25pF 220 5.0k 75 0 60k 100k 2.0k 15pF 800 18k 4.0k 6.0k 100 1.0k 2.2k 3.0k 9.6k 18k 270 240 5.0pF 100pF 30k 2.0 pF 250 20k 5.0k 8.0k 0.2 100k 600 15 2.9k 4.0k 155 2.4k 500 15 500 0.05 Vin This device contains 39 active transistors. Figure 1. Line Regulation and ∆IAdj/Line Test Circuit R2 Cin 1% + 1.0 µF CO IAdj R1 Adjust * Pulse testing required. 1% Duty Cycle is suggested. Vin 1.0 µF 120 1% RL Vout LM337 VIH VIL * VEE MOTOROLA ANALOG IC DEVICE DATA VOH VOL ń + Line Regulation (% V) |V –V | OL OH x 100 |V | OH 3 LM337 Figure 2. Load Regulation and ∆IAdj/Load Test Circuit R2 * Pulse testing required. 1% Duty Cycle is suggested. 1% CO + Cin 1.0 µF IAdj R1 1.0 µF 120 * Adjust –VI Vin Vout LM337 RL (max Load) –VO (min Load) –VO (max Load) IL Load Regulation (mV) = VO (min Load) – VO (max Load) Load Regulation (% VO) = VO (min Load) – VO (max Load) x 100 VO (min Load) Figure 3. Standard Test Circuit 1% R2 1.0 µF Cin VI CO + 1.0 µF Vref IAdj R1 Adjust Vin LM337 Vout 120 IL VO – 1 R1 Vref This assumes IAdj is negligible. To Calculate R2: VO RL R2 = * Pulse testing required. * 1% Duty Cycle is suggested. Figure 4. Ripple Rejection Test Circuit + R2 Cin CAdj 1% 1.0 µF CO Adjust Vin 10µF LM337 R1 Vout 120 D1* + 1.0 µF RL VO 1N4002 Vout = –1.25 V 14.3 V 4.3 V * D1 Discharges CAdj if output is shorted to Ground. f = 120 Hz Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. 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Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. 4 MOTOROLA ANALOG IC DEVICE DATA LM337 Figure 6. Current Limit 0.2 4.0 0 IL = 0.5 A –0.2 –0.4 –0.6 –0.8 Vin = –15 V Vout = –10 V –1.0 IL = 1.5 A I out , OUTPUT CURRENT (A) ∆V out , OUTPUT VOLTAGE CHANGE (%) Figure 5. Load Regulation 3.0 2.0 TJ = 25°C 1.0 –1.2 –1.4 0 –50 –25 0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C) 150 0 10 20 30 40 Vin–Vout , INPUT–OUTPUT VOLTAGE DIFFERENTIAL (Vdc) Figure 7. Adjustment Pin Current Figure 8. Dropout Voltage 3.0 V in – Vout , INPUT–OUTPUT VOLTAGE DIFFERENTIAL (Vdc) IAdj, ADJUSTMENT CURRENT (µA) 80 75 70 65 60 55 50 45 40 Vout = –5.0 V ∆VO = 100 mV 2.5 IL = 1.5 A 2.0 1.0 A 500 mA 1.5 200 mA 20 mA 1.0 –50 –25 0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C) 150 –50 Figure 9. Temperature Stability –25 0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C) 150 Figure 10. Minimum Operating Current I B , QUIESCENT CURRENT (mA) V ref , REFERENCE VOLTAGE (V) 1.27 1.26 1.25 1.24 1.8 1.6 1.4 1.2 1.0 TJ = 25°C 0.8 0.6 0.4 0.2 1.23 –50 –25 0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C) MOTOROLA ANALOG IC DEVICE DATA 150 0 0 10 20 30 40 Vin–Vout , INPUT–OUTPUT VOLTAGE DIFFERENTIAL (Vdc) 5 LM337 Figure 11. Ripple Rejection versus Output Voltage Figure 12. Ripple Rejection versus Output Current 100 CAdj = 10 µF 80 60 RR, RIPPLE REJECTION (dB) RR, RIPPLE REJECTION (dB) 100 Without CAdj 40 Vin – Vout = 5.0 V IL = 500 mA f = 120 Hz TJ = 25°C 20 –5.0 –10 –15 –20 –25 Vout, OUTPUT VOLTAGE (V) –30 –35 Without CAdj 60 40 20 Vin = –15 V Vout = –10 V f = 120 Hz TJ = 25°C 0 0.01 0 0 CAdj = 10 µF 80 –40 0.1 1.0 IO, OUTPUT CURRENT (A) Figure 13. Ripple Rejection versus Frequency Figure 14. Output Impedance 101 Vin = –15 V Vout = –10 V IL = 500 mA TJ = 25°C 80 CAdj =10 µF 60 Without CAdj 20 0 10 100 1.0 k 10 k 100 k 1.0 M Z O , OUTPUT IMPEDANCE ( Ω ) RR, RIPPLE REJECTION (dB) 100 40 100 Vin = –15 V Vout = –10 V IL = 500 mA CL = 1.0 µF TJ = 25°C 10–1 Without CAdj CAdj = 10 µF 10–2 10–3 10 10 M 100 1.0 k 10 k f, FREQUENCY (Hz) 0.8 0.6 0.4 0.2 0 Without CAdj CAdj = 10 µF –0.2 –0.4 0 –0.5 0 Vout = –10 V IL = 50 mA TJ = 25°C CL = 1.0 µF 10 20 t, TIME (µs) 6 30 100 k 1.0 M Figure 16. Load Transient Reponse ∆V out , OUTPUT VOLTAGE DEVIATION (V) Figure 15. Line Transient Response I L , LOAD CURRENT (A) ∆V in, INPUT ∆V out , OUTPUT VOLTAGE CHANGE (V) VOLTAGE DEVIATION (V) f, FREQUENCY (Hz) –1.0 10 40 0.6 0.4 Without CAdj 0.2 0 CAdj = 10 µF –0.2 –0.4 –0.6 Vin = –15 V Vout = –10 V IL = 50 mA TJ = 25°C CL = 1.0 µF 0 –0.5 –1.0 –1.5 0 10 20 30 40 t, TIME (µs) MOTOROLA ANALOG IC DEVICE DATA LM337 APPLICATIONS INFORMATION Basic Circuit Operation The LM337 is a 3–terminal floating regulator. In operation, the LM337 develops and maintains a nominal –1.25 V reference (Vref) between its output and adjustment terminals. This reference voltage is converted to a programming current (IPROG) by R1 (see Figure 17), and this constant current flows through R2 from ground. The regulated output voltage is given by: V out ǒ Ǔ + Vref 1 ) RR2 ) IAdj R2 1 Since the current into the adjustment terminal (IAdj) represents an error term in the equation, the LM337 was designed to control IAdj to less than 100 µA and keep it constant. To do this, all quiescent operating current is returned to the output terminal. This imposes the requirement for a minimum load current. If the load current is less than this minimum, the output voltage will rise. Since the LM337 is a floating regulator, it is only the voltage differential across the circuit which is important to performance, and operation at high voltages with respect to ground is possible. Figure 17. Basic Circuit Configuration + Vout R2 IPROG IAdj + CO Adjust Vref R1 degrading regulation. The ground end of R2 can be returned near the load ground to provide remote ground sensing and improve load regulation. External Capacitors A 1.0 µF tantalum input bypass capacitor (Cin) is recommended to reduce the sensitivity to input line impedance. The adjustment terminal may be bypassed to ground to improve ripple rejection. This capacitor (CAdj) prevents ripple from being amplified as the output voltage is increased. A 10 µF capacitor should improve ripple rejection about 15 dB at 120 Hz in a 10 V application. An output capacitance (CO) in the form of a 1.0 µF tantalum or 10 µF aluminum electrolytic capacitor is required for stability. Protection Diodes When external capacitors are used with any IC regulator it is sometimes necessary to add protection diodes to prevent the capacitors from discharging through low current points into the regulator. Figure 18 shows the LM337 with the recommended protection diodes for output voltages in excess of –25 V or high capacitance values (CO > 25 µF, CAdj > 10 µF). Diode D1 prevents CO from discharging thru the IC during an input short circuit. Diode D2 protects against capacitor CAdj discharging through the IC during an output short circuit. The combination of diodes D1 and D2 prevents CAdj from the discharging through the IC during an input short circuit. Figure 18. Voltage Regulator with Protection Diodes Vin LM337 – Vout Vout + Vout + R2 CAdj + Vref = –1.25 V Typical + Cin CO Adjust Load Regulation The LM337 is capable of providing extremely good load regulation, but a few precautions are needed to obtain maximum performance. For best performance, the programming resistor (R1) should be connected as close to the regulator as possible to minimize line drops which effectively appear in series with the reference, thereby –Vin R1 LM337 Vin Vout D2 1N4002 – Vout D1 1N4002 3.5 JUNCTION-TO-AIR (°C/W) R θ JA, THERMAL RESISTANCE 80 PD(max) for TA = +50°C 70 3.0 Free Air Mounted Vertically 60 ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ 2.0 oz. Copper L Minimum Size Pad 50 2.5 2.0 L 40 1.5 RθJA PD, MAXIMUM POWER DISSIPATION (W) Figure 19. D2PAK Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper Length 1.0 30 0 5.0 10 15 20 25 30 L, LENGTH OF COPPER (mm) MOTOROLA ANALOG IC DEVICE DATA 7 LM337 OUTLINE DIMENSIONS T SUFFIX PLASTIC PACKAGE CASE 221A–06 ISSUE Y F B SEATING PLANE –T – C NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIM Z DEFINES A ZONE WHERE ALL BODY AND LEAD IRREGULARITIES ARE ALLOWED. T S DIM A B C D F G H J K L N Q R S T U V Z 4 A Q 1 2 3 U H K Z L R V J G D INCHES MIN MAX 0.570 0.620 0.380 0.405 0.160 0.190 0.025 0.035 0.142 0.147 0.095 0.105 0.110 0.155 0.018 0.025 0.500 0.562 0.045 0.060 0.190 0.210 0.100 0.120 0.080 0.110 0.045 0.055 0.235 0.255 0.000 0.050 – 0.045 0.080 – MILLIMETERS MIN MAX 14.48 15.75 9.66 10.28 4.82 4.07 0.88 0.64 3.73 3.61 2.66 2.42 3.93 2.80 0.64 0.46 12.70 14.27 1.52 1.15 5.33 4.83 3.04 2.54 2.79 2.04 1.39 1.15 6.47 5.97 1.27 0.00 – 1.15 2.04 – N D2T SUFFIX PLASTIC PACKAGE CASE 936–03 (D2PAK) ISSUE B OPTIONAL CHAMFER A E TERMINAL 4 –T – U S K V B H F 1 2 3 M P J N D 0.010 (0.254) L M R T G C NOTES: 1 DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2 CONTROLLING DIMENSION: INCH. 3 TAB CONTOUR OPTIONAL WITHIN DIMENSIONS A AND K. 4 DIMENSIONS U AND V ESTABLISH A MINIMUM MOUNTING SURFACE FOR TERMINAL 4. 5 DIMENSIONS A AND B DO NOT INCLUDE MOLD FLASH OR GATE PROTRUSIONS. MOLD FLASH AND GATE PROTRUSIONS NOT TO EXCEED 0.025 (0.635) MAXIMUM. DIM A B C D E F G H J K L M N P R S U V INCHES MIN MAX 0.386 0.403 0.356 0.368 0.170 0.180 0.026 0.036 0.045 0.055 0.051 REF 0.100 BSC 0.539 0.579 0.125 MAX 0.050 REF 0.000 0.010 0.088 0.102 0.018 0.026 0.058 0.078 5 _ REF 0.116 REF 0.200 MIN 0.250 MIN MILLIMETERS MIN MAX 9.804 10.236 9.042 9.347 4.318 4.572 0.660 0.914 1.143 1.397 1.295 REF 2.540 BSC 13.691 14.707 3.175 MAX 1.270 REF 0.000 0.254 2.235 2.591 0.457 0.660 1.473 1.981 5 _ REF 2.946 REF 5.080 MIN 6.350 MIN How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; P.O. Box 20912; Phoenix, Arizona 85036. 1–800–441–2447 or 602–303–5454 JAPAN: Nippon Motorola Ltd.; Tatsumi–SPD–JLDC, 6F Seibu–Butsuryu–Center, 3–14–2 Tatsumi Koto–Ku, Tokyo 135, Japan. 03–81–3521–8315 MFAX: [email protected] – TOUCHTONE 602–244–6609 INTERNET: http://Design–NET.com ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298 8 ◊ *LM337/D* MOTOROLA ANALOG IC DEVICE DATA LM337/D