QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER LT3430 DESCRIPTION Demonstration circuit 471 is a 60V, 200kHz, 2A load current, monolithic step-down DC/DC switching converter using the LT3430. With its wide input voltage range, 3A internal power switch, and thermally enhanced package, the LT3430 is a very versatile and powerful IC for DC/DC converters that require compact space and a wide variety of input voltage ranges. The constant 200kHz switching frequency allows all of the components to be small, surface mount devices. The currentmode control topology creates fast transient response and good loop stability with a minimum number of external compensation components and the use of ceramic input and output capacitors if desired. The low resistance internal power switch (0.1Ω) maintains high efficiencies >80% and up to 90%. The SHDN pin and 30µA shutdown current extend battery life. The wide input range allows stepdown configurations with input voltages between 5.5V and 60V. Both steady state and transient operation up to 60V is possible. Syn- chronization of switching frequencies up to 700kHz is possible. Demonstration Circuit 471 is a step-down converter using the LT3430. The circuit is designed for 7.5V–60V input to 5.0V output at 2A load current for automotive, industrial, portable computers, battery chargers, and distributed power systems. This board was designed for wide input voltage range applications where simplicity, small circuit size, and low component count are important as well as up to 2A of load current. The low-ESR tantalum output capacitor reduces output voltage ripple. Replacing this capacitor with a ceramic capacitor not only demonstrates small size and low cost, but the advantage of current-mode control in step-down applications with a simple compensation network and a feedforward capacitor for more rugged stability and excellent transient response. Design files for this circuit board are available. Call the LTC factory. Table 1. Typical Performance Summary PARAMETER CONDITION VALUE Steady State Input Voltage Range VOUT = 5V, IOUT ≤ 2A 7.5– 60V Maximum Transient Input Voltage All Vout (customized) 60V VOUT IOUT ≤ 2A 5V ±3% Maximum Output Current 2A Typical Switching Frequency 200kHz Typical Efficiency VIN = 12V, VOUT = 5V, IOUT = 2A 86% Output Voltage Ripple VIN = 12V, VOUT = 5V, IOUT = 2A 30mVP–P QUICK START PROCEDURE Demonstration circuit 471 is easy to set up to evaluate the performance of the LT3430. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: NOTE: Make sure that the input voltage does not exceed 60V. 1. Connect the 7.5V–60V input power supply to the Vin and GND terminals on the board. 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER 2. Connect an ammeter in series with the in- 6. Connect a voltmeter across the Vout and 3. Connect either power resistors or an elec- 7. After all connections are made, turn on in- 4. Connect an ammeter in series with output 8. The synchronization and shutdown func- put supply to measure input current. GND terminal to measure output voltage. tronic load to the Vout and GND terminals on the board. put power and verify that the output voltage is 5.0V. load to measure output current. tions are optional and their pins can be left floating (disconnected) if their functions are not being used. 5. Connect a voltmeter across the Vin and GND terminals to measure input voltage. + + – – – + + – + LOAD – + – – OPTIONAL + Figure 1. Proper Measurement Equipment Setup 100 90 80 EFFICIENCY (%) 70 60 8VIN 50 12VIN 40 24VIN 30 48VIN 20 55VIN 10 0 0 400 800 1.2k 1.6k 2.0k LOAD CURRENT (mA) Figure 2. Efficiency vs Load Current 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER CUSTOMIZING THE BOARD The components assembled on the board are optimized for a wide input voltage range and a 5V output. The bandwidth can be increased for more specific input voltages such as 12V ±10% or 18V–24V with 36V transient if desired (just a few examples). The adjustable feedback resistors allow the output voltage to be customized. For output voltages below 3V, the boost diode should be moved from D2 to D3 to provide the minimum boost voltage required for the internal power switch. Make sure that the boost capacitor (C8) has a voltage rating greater than or equal to the output voltage for applications where the boost diode is placed in D2. However, the boost capacitor must have a voltage rating greater than the input voltage whenever the boost diode is placed in position D3. D4 is an optional boost voltage blocking diode. For custom applications in which the output voltage is significantly greater than 5V, this blocking diode reduces the boost driver voltage, reducing the power (and thus heat) dissipation inside the IC. It is recommended that a CMHZ5236B zener diode is used in D4 when VOUT = 12V and the junction temperature is hot without the use of the zener. Note that in order to properly install D4, the small trace connecting the anode and cathode of D4 on the board must be separated (an Exacto knife works well) before D4 is soldered to the board. Vin Vout 8V to 40V D2 5V @2A MMSD914 TDK 4.7uF Ceramic C4 0.68uF C5750X7R1H475K C3 Boost Sync Vin Sumida 22uH L1 CEI-122 220 Sw Vout /Shdn U1 LT3430EFE R2 15.4k Bias Vc C4532X5R0J107M C5 C1 220pF C2 22nF Gnd Fb R1 3.3k TDK 100uF Ceramic D1 30BQ060 R3 4.99k IR Figure 3. FireWire peripheral application: 8V–40V input, 5V output @2A with all ceramic capacitors and 3.0mm maximum component height. 3 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER 10V to 14V nominal 40V transient Vin D2 Coptional TAJC105K050 C3 4.7uF MMSD914LT1 50V, X7R, 2220 C5750X7R1H475K 7 13 1 6 4 Vin Boost 5 Sw 5V @2.0A CDRH104R-220 Sumida Vout Coptional2 1.0uF Sync Ceramic U1 LT3430EFE nc 10 Bias R2 15.4k nc Gnd Gnd C5 TPSD107M010R0100 AVX 12 Fb 9 8 /Shdn Vout L1 Vout Vc 14 16V Taiyo Yuden EMK212BJ684MG 2 Sw Vc 11 15 Gnd Sync Gnd /Shdn Vin 3 C4 0.68uF 16 AVX TAJ TDK ceramic D1 R3 4.99k C9 OPT 30BQ060 C2 22nF Vc C1 200pF R5 OPT R1 3.3k R6 Q1 OPT OPT Optional Soft Start Circuitry on Back of Board Figure 4. 10V–14V input with 40V input transient, 5V output @2A. Vin 16V to 36V 48V non-operating transient C3 4.7uF, 50V Ceramic MMSD914T1 SMAZ6V8 11V @2.5A 6 Boost U1 LT3430EFE nc Sw 5 CDRH104R-220 Bias Copt2 1uF, 16V 10 R2 41.2k nc Gnd C5 & C7 2x 100uF, 20V AVX TPS Vc Fb Cff 100pF 12 11 Gnd 9 8 Sw Sync Gnd 1 Vout L1 2 Vout 16 13 4 3 7 Vin Vin 14 /Shdn Gnd 15 300kHz D4 C4 1uF, 16V C5750X7R1H475K Sync D2 R3 4.99k D1 30BQ060 R1 4.7k C1 200pF C2 10nF Figure 5. 16V–36V input with 48V input transient, 11V output @2.5A, 300kHz external synchronization. Note that 2.5A may experience thermal derating. See the data sheet. 4 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER 5 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER 6 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER APPROVED VENDOR LIST VENDOR AAC (was TAD) AAC (was TAD) AAVID ALLEN BRADLEY AMP APEM API DELEVAN AVX AVX AVX AVX BERG BH ELECTRONICS BI TECHNOLOGIES BI TECHNOLOGIES BOURNS CADDOCK ELECTRONICS CENTRAL SEMI CHICAGO MINIAT. LAMP COILCRAFT COMM CON CONNEX COOPER ELECT. TECH. CORNELL DUBILIER CTS CUI-STACK DALE (see Vishay) DALE (see Vishay) DATA DISPLAY PRODUCT DIODES INC. ELECTRONIC CONCEPTS EPSON FAIRCHILD FAIRCHILD FAIRCHILD FCI FUKUSHIMA FUJI GENERAL SEMICONDUCTOR GOWANDA GRAYHILL HARRIS HEWLETT PACKARD HITACHI PHONE NUMBER (800) 508-1521 (714) 255-9186 (714) 556-2665 (800) 592-4888 (717) 564-0100 (718) 246-1007 (716) 652-3600 (843) 946-0362 (843) 946-0524 (207) 282-5111 (843) 946-0323 (800) 237-2374 (952) 894-9590 (714) 447-2656 (714) 447-2345 (801) 750-7253 (541) 496-0700 (631) 435-1110 (201) 489-8989 (847) 639-6400 (626) 301-4200 (805) 378-6464 (561) 752-5000 (508) 996-8561 (219) 293-7511 (503) 643-4899 (605) 665-1627 (605) 665-9301 (800) 421-6815 (805) 446-4800 (908) 542-7880 (310) 787-6300 (207) 775-4502 (408) 822-2126 (888) 522-5372 (717) 767-8005 (818) 765-8300 (201) 712-0555 (516) 847-3000 (716) 532-2234 (708) 354-1040 (800) 442-7747 (800) 235-0312 (408) 433-1990 PART TYPE WEBSITE ADDRESS CHIP RESISTORS HEAT SINKS CARBON RESISTORS PC MOUNT BNC SMD TOGGLE/PB SWITCH INDUCTORS CHIP CAPS CHIP RESISTORS TANTALUM CAPS HIGH VOLTAGE CAPS CONNECTORS INDUCTORS TRANSFORMERS RES./RES. NETWORKS POTENTIOMETERS, SIPS HIPO. RES., SIPS, DIPS SMALL SIGNAL DISCRETES LEDS INDUCTORS HEADERS, SHUNTS BNC CONNECTORS INDUCTORS CAPACITORS RESISTOR ARRAYS POWER CONNECTORS INDUCTORS SENSE RESISTORS LEDS DIODES 400V FILM CAPACITORS CRYSTALS LOGIC MOSFETS CRG (CUST. RESPONSE) HOT PLUG CONNECTORS MPC RESISTORS SCHOTTKY DIODES DIODES INDUCTORS DIP SWITCHES LOGIC IR LED RF POWER AMPS 7 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER IDT IR IRC ITW PAKTRON JOHNSON COMPONENTS JOHNSON COMPONENTS KEMET KEMET KETEMA KEYSTONE LITEON LTC MAGNETICS MARCON METHODE MF ELECTRONICS MICROCHIP MICRO PLASTICS MICRO-SEMI MIDCOM MIDCOM MILL-MAX MINICIRCUITS MOTOROLA MURATA ELECTRONICS MURATA ELECTRONICS MURATA ELECTRONICS NEC/TOKIN NICHIA NICHICON ON SEMICONDUCTOR ON SHORE PANASONIC PANASONIC PANASONIC PERICOM PHILIPS PHILIPS PHILIPS PULSE QT OPTOELECTRONICS RAYCHEM RG ALLEN RF MICRO DEVICES SAMTEC SANYO SCHOTT (408) 727-6116 (310) 322-3331 (361) 992-7900 (708) 667-3444 (650) 948-6533 (760) 434-5961 (408) 986-0424 (864) 963-6300 (714) 630-0081 (718) 956-8900 (408) 241-4588 (408) 432-1900 (800) 245-3984 (847) 696-2000 (800) 323-6864 (914) 576-6570 (602) 786-7200 (870) 453-8861 (617) 926-0404 (605) 886-4385 (800) 643-2661 (516) 922-6000 (718) 934-4500 (800) 441-2447 (770) 436-1300 (800) 831-9172 (770) 433-5789 (510) 324-4110 (408) 573-0933 (847) 843-7500 (602) 244-6600 (602) 921-3000 (714) 373-7334 (201) 348-5217 (201) 373-7334 (408) 435-0800 (914) 246-2811 (914) 247-2036 (508) 851-2200 (619) 674-8100 (408) 720-1440 (800) 227-4856 (818) 765-8300 (336) 664-1233 (800) 726-8329 (619) 661-6835 (507) 532-3201 LOGIC IC MOSFETS SENSE RESISTORS CAPACITORS RF CONNECTORS RF CONNECTORS TANTALUM CAPS CRG (CUST. RESPONSE) SURGE SUPPRESSORS JACKS, TURRETS LEDS, DIODES HIGH PERF. I.C.S TOROID CORES ETC. HIGH C/V CAPACITORS ZIF SOCKETS CRYSTAL OSCILLATORS MICROCONTROLLER IC NYLON STANDOFFS DIODES INDUCTORS INDUCTORS TURRETS RF TRANSFORMERS LOGIC, REGS CAPS., INDUCTORS, CRG (CUST. RESPONSE) RF DEVICES INDUCTORS/HI C/V CAPS WHITE LEDS ELECTROLYTIC CAPACITOR DISCRETE DIODES ETC. TERMINATORS INDUCTORS, POLY CAPS LEDS SWITCHES LOGIC IC INDUCTORS PLANAR INDUCTORS DISCRETES, I.C.s INDUCTORS RF SWITCH FUSES METAL OXIDE RESISTORS RF2138 / RF2140 WIRE JUMPERS OSCON CAPS INDUCTORS, XFORMERS 8 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER SCHURTER SIGNATRON SIEMENS SILICONIX SILICONIX SPRAGUE SULLINS SUMIDA SUMIDA TAIYO YUDEN TAIYO YUDEN TEKTRONIX TEMIC THERMALLOY THIN FILM TECHNOLOGY TOCOS TOKIN (NEC) TOKO TOSHIBA TOSHIBA UNITED CHEMICON VISHAY VISHAY VITRAMON WIMA ZETEX ZIERICK (707) 778-6311 (909) 464-1883 (108) 257-7910 (800) 554-5565 (408) 988-8000 (207) 324-4140 (760) 744-0125 (847) 956-0667 (408) 982-9660 (408) 573-4150 (800) 348-2496 (800) 835-9433 (408) 970-5700 (972) 243-4321 (507) 625-8445 (847) 884-6664 (510) 324-4110 (847) 699-3430 (714) 455-2000 (949) 455-2000 (847) 696-2000 (605) 665-9301 (605) 665-9301 (203) 268-6261 (914) 347-2474 (631) 366-5068 (800) 882-8020 FUSES AND HOLDERS DB9 CONNECTORS OPTO MOSFETS MOSFETS CAPACITORS HEADERS, SHUNTS INDUCTORS INDUCTORS CHIP CAPS / RES. CRG (CUST. RESPONSE) SCOPE PROBE SOCKETS IR PHOTO DIODE HEAT SINKS THIN FILM CHIP RESISTORS SMD POTENTIOMETERS CAPS., INDUCTORS, RF PRODUCTS SINGLE GATE LOGIC LOGIC ELECTROLYTIC CAPACITOR ZENER/SM. SIGNAL DIODES INDUCTORS, SENSE Rs CERAMIC CHIP CAPACITOR PAPER/FILM CAPACITORS SMALL SIGNAL DISCRETES STAKED PINS 9 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER 10 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 471 2A, 200KHZ HIGH VOLTAGE BUCK CONVERTER 11 VIN 7.5V-60V E1 D3 MMSD914T1 2 1 VIN + C7 OPT E2 GND SHDN E3 SYNC 3 3 15 SYNC 14 4 1 BOOST SHDN SW SYNC SW U1 BIAS LT3430EFE NC NC GND 8 GND FB GND GND 9 D2 MMSD914T1 1 2 D4 SMAZ7V5 2 1 SOD123 OPT C4 0.68uF 16V 6 VIN VIN 7 13 C BOOST OPT C3 4.7uF 100V SHDN E4 2 2 1 D L1 33uH 1 SW E5 VOUT 2 UP3B-330 1 D 4 5 C9 OPT D1 30BQ060 SMC 10 R2 15.4k 1% 12 FB R4 OPT VOUT 5V@2A C6 OPT 0805 C5 2 5 + 100uF C 10V 7343 C8 OPT E6 GND VC 16 11 VC 3 C1 220pF C2 0.022uF R6 OPT 1 2 R1 3.3k R3 4.99k 1% Q1 MMBT2222A OPT R5 OPT B B NOTE: UNLESS OTHERWISE SPECIFIED A CONTRACT NO. 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE IN MICROFARADS, 0603. 2. FOR ALL OPTIONAL COMPONENTS ON BOARDS: Q1, R5, R6, C9: SHOW OUTLINE AND REFERENCE DESIGNATORS. D3, D4: NO OUTLINE, SHOW REFERENCE DESIGNATORS. C6, C7, C8, R4: NO OUTLINE, NO REFERENCE DESIGNATORS. APPROVALS DRAWN: CHECKED: APPROVED: ENGINEER: KEITH S. DESIGNER: TECHNOLOGY KIM T. TITLE: SCHEMATIC 4 3 A 2A, 200KHz HIGH VOLTAGE BUCK CONVERTER SIZE DWG NO. A DATE: 5 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only Wednesday, July 10, 2002 2 REV DC471A-1 * LT3430EFE SHEET 1 1 A OF 1 BILL OF MATERIALS DC471A-1 Linear Technology Corporation LT3430EFE 6/17/2005 12:07 PM 2A, 200KHz HIGH VOLTAGE BUCK CONVERTER ENG: KEITH S. Item Qty Reference 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 1 1 1 1 0 1 0 0 0 1 1 0 0 6 1 0 0 1 1 1 0 1 4 4 Part Description C1 C2 C3 C4 CAP, NPO 220pF 25V 10% CAP, X7R 0.022uF 16V 10% CAP, Y5V 4.7uF 100V, 80%, C-THCR60 CAP, X7R 0.68uF 16V 20% OR CAP, X5R 1.0uF 16V 10%, 0805 C5 CAP, TANT. 100uF 10V 20%, 7343 C6 CAP, 0805 C7 CAP, C SIZE, 6032 C8,C9 CAP, 0603 D1 DIODE SCHOTTKY,3A, 60V,SMA-DIODE D2 DIODE, 200mA, 100V, SOD123 D3 DIODE, 200mA, 100V, SOD123 D4 DIODE ZENER, SMA-DIODE E1-E6 TP, TURRET, .094" L1 IND, SMT, 33uH, L-COIL-UP3B OR IND, SMT, 47uH, L-COIL-UP4B Q1 TRANS, MMBT2222A, SOT23 R1 RES, 3.3k 5%, 0603 R2 RES, 15.4k 1%, 0603 R3 RES, 4.99k 1%, 0603 R4,R5,R6 RES, 0603 U1 IC, LT3430EFE, TSSOPFE16 MTG HOLES AT 4 CORNERS STANDOFF, NYLON HEX #4-40 x 1/4" SCREW, #4-40 x 1/4 Manufacture / Part # AVX, 06033A221KAT1A AVX, 0603YC223KAT1A UNITED CHEMI-CON, THCR60E2A475ZT TAIYO YUDEN, EMK212BJ684MG TAIYO YUDEN, EMK212BJ105ZG AVX, TPSD107M010R0100 OPT OPT OPT IR, 30BQ060 ON SEMI., MMSD914T1 ON SEMI., MMSD914T1 (OPT) DIODES INC., SMAZ7V5 (OPT) MILL-MAX, 2501-2 COILTRONICS, UP3B-330 COILTRONICS, UP4B-470 DIODES INC., MMBT2222A-7 (OPT) AAC, CR16-332JM AAC, CR16-1542FM AAC, CR16-4991FM OPT LINEAR TECH., LT3430EFE MICRO PLASTICS, #14HTSP101 ANY NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS. 2. INSTALL 4 STANDOFFS AT 4 CORNERS OF BOARD AND ON THE BOTTOM SIDE. Page 1 - of - 1