LM350 THREE TERMINAL ADJUSTABLE POSITIVE VOLTAGE REGULATOR

Size: px

Start display at page:

Download "LM350 THREE TERMINAL ADJUSTABLE POSITIVE VOLTAGE REGULATOR"

Matilda Kennedy
5 years ago
Views:

1 Order this document by /D The is an adjustable threeterminal positive voltage regulator capable of supplying in excess of 3. A over an output voltage range of 1.2 V to 33 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 also makes an especially simple adjustable switching regulator, a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the can be used as a precision current regulator. Guaranteed 3. A Output Current Output able between 1.2 V and 33 V Load Regulation Typically. Line Regulation Typically.5%/V Internal Thermal Overload Protection Internal Short Circuit Current Limiting Constant with Temperature Output Transistor Safe Area Compensation Floating Operation for High Voltage Applications Standard 3lead Transistor Package Eliminates Stocking Many Fixed Voltages THREETERMINAL ADJUSTABLE POSITIVE VOLTAGE REGULATOR T SUFFIX PLASTIC PACKAGE CASE 221A SEMICONDUCTOR TECHNICAL DATA Pin Heatsink surface is connected to Pin 2. Simplified Application vout Cin*.1µF IAdj 24 C O** 1µF ORDERING INFORMATION * = Cin is required if regulator is located an appreciable distance from power supply filter. ** = CO is not needed for stability, however, it does improve transient response V.1 R 2. I Adj Since IAdj is controlled to less than 1 µa, the error associated with this term is negligible in most applications. Device T Operating Temperature Range TJ = to 125 C Package Plastic Power BT# TJ = 4 to 125 C Plastic Power # Automotive temperature range selections are available with special test conditions and additional tests. Contact your local Motorola sales office for information. MOTOROLA ANALOG IC DEVICE DATA Motorola, Inc Rev 1

2 MAXIMUM RATINGS Rating Symbol Value Unit InputOutput Voltage Differential VIVO 35 Vdc Power Dissipation PD Internally Limited W Operating Junction Temperature Range TJ 4 to 125 C Storage Temperature Range Tstg 65 to 15 C Soldering Lead Temperature (1 seconds) Tsolder 3 C ELECTRICAL CHARACTERISTICS (VIVO = 5. V; IL = 1.5 A; TJ = Tlow to Thigh; Pmax [Note 1], unless otherwise noted.) Characteristics Figure Symbol Min Typ Max Unit Line Regulation (Note 2) 1 Regline.5.3 %/V TA = 25 C, 3. V VIVO 35 V Load Regulation (Note 2) TA = 25 C, 1 ma Il 3. A VO 5. V VO 5. V Thermal Regulation, Pulse = 2 ms, (TA = 25 C) 2 Regload mv % VO Regtherm.2 % VO/W ment Pin Current 3 IAdj 5 1 µa ment Pin Current Change 3. V VIVO 35 V 1 ma IL 3. A, PD Pmax Reference Voltage 3. V VIVO 35 V 1 ma IO 3. A, PD Pmax Line Regulation (Note 2) 3. V VIVO 35 V 1,2 IAdj.2 5. µa 3 Vref V 1 Regline.2.7 %/V Load Regulation (Note 2) 1 ma IL 3. A VO 5. V VO 5. V 2 Regload mv % VO Temperature Stability (Tlow TJ Thigh) 3 TS 1. % VO Minimum Load Current to Maintain Regulation (VIVO = 35 V) 3 ILmin ma Maximum Output Current VIVO 1 V, PD Pmax VIVO = 3 V, PD Pmax, TA = 25 C 3 Imax A RMS Noise, % of VO TA= 25 C, 1 Hz f 1 khz Ripple Rejection, VO = 1 V, f = 12 Hz (Note 3) Without CAdj CAdj = 1 µf Long Term Stability, TJ = Thigh (Note 4) TA= 25 C for Endpoint Measurements 4 RR N.3 % VO S.3 1. %/1. k Hrs. db Thermal Resistance, JunctiontoCase Peak (Note 5) Average (Note 6) RθJC C/W NOTES: 1. T low to T high = to 125 C; P max = 25 W for T; T low to T high = 4 to 125 C; P max = 25 W for BT 2. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used. 3. C Adj, when used, is connected between the adjustment pin and ground. 4. Since LongTerm Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot. 5. Thermal Resistance evaluated measuring the hottest temperature on the die using an infrared scanner. This method of evaluation yields very accurate thermal resistance values which are conservative when compared to the other measurement techniques. 6. The average die temperature is used to derive the value of thermal resistance junction to case (average). 2 MOTOROLA ANALOG IC DEVICE DATA

3 Representative Schematic Diagram K 6.3V K K 6.7K 12K 5.pF 6.8K K 6.3V 6.3V 3 pf 3 pf 2.4K K 5.8K K 12.5K 4.45 Figure 1. Line Regulation and IAdj/Line Test Circuit * VCC Line Regulation (%/V) = V OH VOL VOL x 1 VIH VIL IL VOH VOL Cin.1µF IAdj 24 CO 1µF RL * Pulse Testing Required: Duty Cycle is suggested. MOTOROLA ANALOG IC DEVICE DATA 3

4 Figure 2. Load Regulation and IAdj/Load Test Circuit Load Regulation (% VO) = V O (min Load) VO (max Load) VO (min Load) X 1 Load Regulation (mv) = VO (min Load) VO (max Load) VO (min Load) IL VO (max Load) Cin.1µF IAdj 24 CO 1.µF * RL (max Load) RL (min Load) * Pulse Testing Required: Duty Cycle is suggested. Figure 3. Standard Test Circuit IL VI Cin.1µF IAdj 24 Vref CO 1.µF RL VO ISET Pulse Testing Required: Duty Cycle is suggested. To Calculate : = ISET 1.25 V Assume ISET = 5.25 ma 24V 14V f = 12 Hz Figure 4. Ripple Rejection Test Circuit = 1 V IL Cin.1µF 24 D1 * 1N42 CO 1.µF RL VO 1.65K ** CAdj 1µF *D1 Discharges CAdj if Output is Shorted to Ground. **CAdj provides an AC ground to the adjust pin. 4 MOTOROLA ANALOG IC DEVICE DATA

5 Figure 5. Load Regulation Figure 6. Current Limit I Adj, ADJUSTMENT PIN CURRENT ( µ A) V out, OUTPUT VOLTAGE CHANGE (%) = 15 V = 1 V IL = 1.5 A IL =.5 A TJ, JUNCTION TEMPERATURE ( C) Figure 7. ment Pin Current TJ, JUNCTION TEMPERATURE ( C) I out, OUTPUT CURRENT (A) V in V out, INPUTOUTPUT VOLTAGE DIFFERENTIAL (Vdc) , INPUT VOLTAGE DIFFERENTIAL (Vdc) TJ = 15 C TJ = 55 C Figure 8. Dropout Voltage V = 1 mv IL = 3. A IL = 2. A IL = 5 ma IL = 2 ma IL = 2 ma TJ, JUNCTION TEMPERATURE ( C) V ref, REFERENCE VOLTAGE (V) Figure 9. Temperature Stability TJ, JUNCTION TEMPERATURE ( C) IB, QUIESCENT CURRENT (ma) Figure 1. Minimum Operating Current TJ = 55 C TJ = 15 C , INPUTOUTPUT VOLTAGE DIFFERENTIAL (Vdc) MOTOROLA ANALOG IC DEVICE DATA 5

6 Figure 11. Ripple Rejection versus Output Voltage Figure 12. Ripple Rejection versus Output Current 1 14 RR, RIPPLE REJECTION (db) = 5 V IL = 5 ma f = 12 Hz CAdj = 1 µf Without CAdj RR, RIPPLE REJECTION (db) = 5 V IL = 5 ma f = 12 Hz Without CAdj CAdj = 1 µf , OUTPUT VOLTAGE (V) Iout, OUTPUT CURRENT (A) Figure 13. Ripple Rejection versus Frequency Figure 14. Output Impedance 1 11 RR, RIPPLE REJECTION (db) Without CAdj IL = 5 ma = 15 V = 1 V CAdj = 1 µf ZO, OUTPUT IMPEDANCE ( Ω ) = 15 V = 1 V IL = 5 ma Without CAdj 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 out, OUTPUT VOLTAGE DEVIATION (V) V in, INPUT VOLTAGE CHANGE (V) Figure 15. Line Transient Response = 1 V IL = 5 ma CL = 1. µf; CAdj = 1 µf CL = ; Without CAdj t, TIME (µs) V out, OUTPUT VOLTAGE DEVIATION (V) I L, LOAD CURRENT (A) Figure 16. Load Transient Response CL = 1. µf; CAdj = 1 µf CL = ; Without CAdj = 15 V = 1 V INL = 5 ma t, TIME (µs) IL 6 MOTOROLA ANALOG IC DEVICE DATA

7 APPLICATIONS INFORMATION Basic Circuit Operation The is a threeterminal 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 (see Figure 17), and this constant current flows through to ground. The regulated output voltage is given by: = Vref (1 ) IAdj Since the current from the terminal (IAdj) represents an error term in the equation, the was designed to control IAdj 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 External Capacitors A.1 µf disc or 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. Although the is stable with no output capacitance, like any feedback circuit, certain values of external capacitance can cause excessive ringing. An output capacitance (CO) in the form of a 1 µf tantalum or 25 µf aluminum electrolytic capacitor on the output swamps this effect and insures 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 (CO > 25 µf, CAdj > 1 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 discharging through the IC during an input short circuit. Vref IPROG Figure 18. Voltage Regulator with Protection Diodes IAdj Vref = 1.25 V Typical Load 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 () 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. Cin D1 1N42 D2 CAdj CO 1N42 MOTOROLA ANALOG IC DEVICE DATA 7

8 Figure 19. Laboratory Power Supply with able Current Limit and Output Voltage D6 32V 1.1µF (1) 1 1N42 1 RSC 2 2 (2) Current 1K Limit Q1 2N3822 D1 1N41 1N41 D2 5.K 2 Voltage 1N41 24 D5 IN41 D3 1µF IO VO 1.µF Tantalum 1V Diodes D1 and D2 and transistor Q2 are added to allow adjustment of output voltage to V. Q2 2N564 D4 1N41 Output Range: VO 25 V IO 1.5 A D6 protects both s during an input short circuit. 1V Figure 2. able Current Limiter Figure V Electronic Shutdown Regulator 25V * To provide current limiting of IO to the system ground, the source of the FET must be tied to a negative voltage below 1.25 V. V ref IDSS Vref = IOmax IDSS VO < V(BR)DSS 1.25 V VSS ILmin IDSS < IO < 3. A As shown O < IO < 1. A 62 1 VSS* Iout D1 1N41 D2 1N41 2N D1 1N42 12 MPS k 1.µF Minimum = 1.25 V D1 protects the device during an input short circuit. TTL Control Figure 22. Slow TurnOn Regulator Figure 23. Current Regulator Iout 24 1N41 5k IAdj MPS297 1µF Iout. V ref. I Adj 1.25 V 1 ma Iout 3. A 8 MOTOROLA ANALOG IC DEVICE DATA

9 OUTLINE DIMENSIONS H Q Z L V G B N D A K F T U S R J T SUFFIX PLASTIC PACKAGE CASE 221A6 ISSUE Y C T SEATING PLANE NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, CONTROLLING DIMENSION: INCH. 3. DIMENSION Z DEFINES A ZONE WHERE ALL BODY AND LEAD IRREGULARITIES ARE ALLOWED. INCHES MILLIMETERS DIM MIN MAX MIN MAX A B C D F G H J K L N Q R S T U V Z MOTOROLA ANALOG IC DEVICE DATA 9

10 NOTES 1 MOTOROLA ANALOG IC DEVICE DATA

11 NOTES MOTOROLA ANALOG IC DEVICE DATA 11

12 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. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; JAPAN: Nippon Motorola Ltd.; TatsumiSPDJLDC, 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. Ltd.; 8B Tai Ping Industrial Park, INTERNET: 51 Ting Kok Road, Tai Po, N.T., Hong Kong MOTOROLA ANALOG IC DEVICE /D DATA

LM337MT MEDIUM CURRENT THREE TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR

LM337MT MEDIUM CURRENT THREE TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR Order this document by /D The is an adjustable threeterminal negative voltage regulator capable of supplying in excess of 5 ma over an output voltage range of 1.2 V to 37 V. This voltage regulator is exceptionally