LM337 THREE TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR

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1 Order this document by /D The is an adjustable 3terminal 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 blowout proof. The 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 can be used as a precision current regulator. Output Current in Excess of 1.5 A Output able between 1.2 V and 37 V Internal Thermal Overload Protection Internal Short Circuit Current imiting Constant with Temperature Output Transistor SafeArea Compensation Floating Operation for High Voltage Applications Eliminates Stocking many Fixed Voltages Available in Surface Mount D2PAK and Standard 3ead Transistor Package THREETERMINA ADJUSTABE NEGATIVE VOTAGE REGUATOR SEMINDUCTOR TECHNICA DATA T SUFFIX PASTIC PACKAGE CASE 221A Heatsink surface connected to Pin Standard Application Pin IPROG Cin* 1. µf R1 12 ** 1. µf D2T SUFFIX PASTIC PACKAGE CASE 936 (D2PAK) Heatsink surface (shown as terminal 4 in case outline drawing) is connected to Pin 2. ORDERING INFORMATION *Cin is required if regulator is located more than 4 inches from power supply filter. * A 1. µf solid tantalum or 1 µf aluminum electrolytic is recommended. ** is necessary for stability. A 1. µf solid tantalum or 1 µf aluminum electrolytic ** is recommeded. V out 1.25 V.1 R 2 R 1. Device BD2T BT D2T T Operating Temperature Range TJ = 4 to 125 C TJ = to 125 C Package Surface Mount Insertion Mount Surface Mount Insertion Mount MOTOROA ANAOG IC DEVICE DATA Motorola, Inc Rev 1 1

2 MAXIMUM RATINGS Rating Symbol Value Unit InputOutput Voltage Differential VIVO 4 Vdc Power Dissipation Case 221A TA = 25 C PD Internally imited W Thermal Resistance, JunctiontoAmbient θja 65 C/W Thermal Resistance, JunctiontoCase θjc 5. C/W Case 936 (D2PAK) TA = 25 C PD Internally imited W Thermal Resistance, JunctiontoAmbient θja 7 C/W Thermal Resistance, JunctiontoCase θjc 5. C/W Operating Junction Temperature Range TJ 4 to 125 C Storage Temperature Range Tstg 65 to 15 C EECTRICA CHARACTERISTICS ( VIVO = 5. V; IO =.5 A for T package; TJ = Tlow to Thigh [Note 1]; Imax and Pmax [Note 2].) Characteristics Figure Symbol Min Typ Max Unit ine Regulation (Note 3), TA = 25 C, 3. V VIVO 4 V 1 Regline.1.4 %/V oad Regulation (Note 3), TA = 25 C, 1 ma IO Imax VO 5. V VO 5. V 2 Regload mv % VO Thermal Regulation, TA = 25 C (Note 6), 1 ms Pulse Regtherm.3.4 % VO/W ment Pin Current µa ment Pin Current Change, 2.5 V VIVO 4 V, 1 ma I Imax, PD Pmax, TA = 25 C Reference Voltage, TA = 25 C, 3. V VIVO 4 V, 1 ma IO Imax, PD Pmax, TJ = Tlow to Thigh 1, µa 3 Vref ine Regulation (Note 3), 3. V VIVO 4 V 1 Regline.2.7 %/V V oad Regulation (Note 3), 1 ma IO Imax VO 5. V VO 5. V 2 Regload mv % VO Temperature Stability (Tlow TJ Thigh) 3 TS.6 % VO Minimum oad Current to Maintain Regulation 3 Imin ma ( VIVO 1 V) ( VIVO 4 V) Maximum Output Current VIVO 15 V, PD Pmax, T Package VIVO 4 V, PD Pmax,, T Package 3 Imax RMS Noise, % of VO, TA = 25 C, 1 Hz f 1 khz N.3 % VO Ripple Rejection, VO = 1 V, f = 12 Hz (Note 4) 4 RR db CAdj = 1 µf ongterm Stability, TJ = Thigh (Note 5), TA = 25 C for Endpoint Measurements S.3 1. %/1. k Hrs. Thermal Resistance JunctiontoCase, T Package RθJC 4. C/W NOTES: 1. T low to T high = to 125 C, for T, D2T. T low to T high = 4 to 125 C, for BT, BD2T. 2. I max = 1.5 A, P max = 2 W 3. oad and line regulation are specified at constant junction temperature. Change in V O because of heating effects is covered under the Thermal Regulation specification. Pulse testing with a low duty cycle is used. 4. C Adj, when used, is connected between the adjustment pin and ground. 5. Since ong 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. A 2 MOTOROA ANAOG IC DEVICE DATA

3 Representative Schematic Diagram 1 2.5k 2.k k 1k 8 15pF 25pF 5.k k 1k 8 15pF 2.k 18k 4.k 1.k 6.k 1 9.6k 3.k 2.2k 18k 3k k 8.k 4.k 2k 1pF 5.pF 24 5.k 1k 5 2.4k pf This device contains 39 active transistors. Figure 1. ine Regulation and /ine Test Circuit 1% Cin 1. µf 1. µf * Pulse testing required. 1% Duty Cycle is suggested. R1 12 1% R * VEE VIH VI V V O OH ine Regulation (% V) V OH x 1 VOH VO MOTOROA ANAOG IC DEVICE DATA 3

4 Figure 2. oad Regulation and /oad Test Circuit 1% * Pulse testing required. 1% Duty Cycle is suggested. Cin 1. µf 1. µf R1 12 VI I * R (max oad) VO (min oad) VO (max oad) VO (min oad) VO (max oad) oad Regulation (mv) = VO (min oad) VO (max oad) oad Regulation (% VO) = x 1 VO (min oad) Figure 3. Standard Test Circuit 1% VI Cin 1. µf 1. µf R VO Vref R1 12 I To Calculate : VO = 1 R1 Vref This assumes is negligible. * Pulse testing required. * 1% Duty Cycle is suggested. Figure 4. Ripple Rejection Test Circuit Cin 1. µf 1% CAdj 1µF 1. µf R VO R1 12 D1* 1N V = 1.25 V 4.3 V f = 12 Hz * D1 Discharges CAdj if output is shorted to Ground. 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. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. 4 MOTOROA ANAOG IC DEVICE DATA

5 I, OUTPUT VOTAGE CHANGE (%) Figure 5. oad Regulation = 15 V = 1 V I =.5 A I = 1.5 A TJ, JUNCTION TEMPERATURE ( C) I out, OUTPUT CURRENT (A) Figure 6. Current imit , INPUTOUTPUT VOTAGE DIFFERENTIA (Vdc) 8 Figure 7. ment Pin Current 3. Figure 8. Dropout Voltage, ADJUSTMENT CURRENT ( µa) TJ, JUNCTION TEMPERATURE ( C) V in V out, INPUTOUTPUT VOTAGE DIFFERENTIA (Vdc) = 5. V VO = 1 mv I = 1.5 A TJ, JUNCTION TEMPERATURE ( C) 1. A 5 ma 2 ma 2 ma Vref, REFERENCE VOTAGE (V) Figure 9. Temperature Stability B, QUIESCENT CURRENT (ma) Figure 1. Minimum Operating Current TJ, JUNCTION TEMPERATURE ( C) , INPUTOUTPUT VOTAGE DIFFERENTIA (Vdc) MOTOROA ANAOG IC DEVICE DATA 5

6 1 Figure 11. Ripple Rejection versus Output Voltage 1 Figure 12. Ripple Rejection versus Output Current RR, RIPPE REJECTION (db) CAdj = 1 µf = 5. V 2 I = 5 ma f = 12 Hz , OUTPUT VOTAGE (V) RR, RIPPE REJECTION (db) = 15 V = 1 V f = 12 Hz CAdj = 1 µf IO, OUTPUT CURRENT (A) 1 Figure 13. Ripple Rejection versus Frequency 11 Figure 14. Output Impedance RR, RIPPE REJECTION (db) CAdj =1 µf = 15 V = 1 V I = 5 ma, OUTPUT IMPEDANCE ( ) O Ω Z = 15 V = 1 V I = 5 ma C = 1. µf CAdj = 1 µf k 1 k 1 k 1. M 1 M f, FREQUENCY (Hz) k 1 k 1 k 1. M f, FREQUENCY (Hz) V in, INPUT V out, OUTPUT VOTAGE CHANGE (V) VOTAGE DEVIATION (V) Figure 15. ine Transient Response = 1 V I = 5 ma C = 1. µf CAdj = 1 µf t, TIME (µs) V out VOTAGE DEVIATION (V), OAD, OUTPUT I CURRENT (A) Figure 16. oad Transient Reponse CAdj = 1 µf = 15 V = 1 V I = 5 ma C = 1. µf t, TIME (µs) 6 MOTOROA ANAOG IC DEVICE DATA

7 APPICATIONS INFORMATION Basic Circuit Operation The is a 3terminal floating regulator. In operation, the 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 from ground. The regulated output voltage is given by: V out V ref.1 R 2 R 1. I Adj R 2 Since the current into the adjustment terminal () represents an error term in the equation, the was designed to control to less than 1 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 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 Vref R1 IPROG Vref = 1.25 V Typical oad Regulation The 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 degrading regulation. The ground end of can be returned near the load ground to provide remote ground sensing and improve load regulation. External Capacitors A 1. 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 1 µf capacitor should improve ripple rejection about 15 db at 12 Hz in a 1 V application. An output capacitance () in the form of a 1. µf tantalum or 1 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 with the recommended protection diodes for output voltages in excess of 25 V or high capacitance values ( > 25 µf, CAdj > 1 µf). Diode D1 prevents 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 CAdj Cin R1 D2 1N42 D1 1N42 Figure 19. D2PAK Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper ength R θja, THERMA RESISTANCE JUNCTION-TO-AIR ( C/W) Free Air Mounted Vertically Minimum Size Pad PD(max) for TA = 5 C RθJA 2. oz. Copper ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ , ENGTH OF PPER (mm) P D, MAXIMUM POWER DISSIPATION (W) MOTOROA ANAOG IC DEVICE DATA 7

8 OUTINE DIMENSIONS T SUFFIX PASTIC PACKAGE CASE 221A6 ISSUE Y H Q Z V G B N D A K F T U C T SEATING PANE J S R NOTES: 1. DIMENSIONING AND TOERANCING PER ANSI Y14.5M, NTROING DIMENSION: INCH. 3. DIM Z DEFINES A ZONE WHERE A BODY AND EAD IRREGUARITIES ARE AOWED. DIM A B C D F G H J K N Q R S T U V Z INCHES MIN MAX MIIMETERS MIN MAX B K F D J.1 (.254) M T C A G S H D2T SUFFIX PASTIC PACKAGE CASE 9363 (D2PAK) ISSUE B OPTIONA CHAMFER T TERMINA 4 E U N M R V P NOTES: 1 DIMENSIONING AND TOERANCING PER ANSI Y14.5M, NTROING DIMENSION: INCH. 3 TAB NTOUR OPTIONA WITHIN DIMENSIONS A AND K. 4 DIMENSIONS U AND V ESTABISH A MINIMUM MOUNTING SURFACE FOR TERMINA 4. 5 DIMENSIONS A AND B DO NOT INCUDE MOD FASH OR GATE PROTRUSIONS. MOD FASH AND GATE PROTRUSIONS NOT TO EXCEED.25 (.635) MAXIMUM. INCHES MIIMETERS DIM MIN MAX MIN MAX A B C D E F.51 REF REF G.1 BSC 2.54 BSC H J.125 MAX MAX K.5 REF 1.27 REF M N P R 5 REF 5 REF S.116 REF REF U.2 MIN 5.8 MIN V.25 MIN 6.35 MIN How to reach us: USA / EUROPE / ocations Not isted: Motorola iterature Distribution; JAPAN: Nippon Motorola td.; TatsumiSPDJDC, 6F SeibuButsuryuCenter, P.O. Box 2912; Phoenix, Arizona or Tatsumi KotoKu, Tokyo 135, Japan MFAX: RMFAX@ .sps.mot.com TOUCHTONE ASIA/PACIFIC: Motorola Semiconductors H.K. td.; 8B Tai Ping Industrial Park, INTERNET: 51 Ting Kok Road, Tai Po, N.T., Hong Kong MOTOROA ANAOG IC DEVICE /D DATA