QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC CONVERTER LTC3251EMSE DESCRIPTION Demonstration circuit 506A is a two-phase, step down charge pump DC/DC converter featuring the LTC3251EMSE. It produces regulated 1.5V output voltage at up to 500mA of output current from 3.2V to 5.5V input. A unique two phase, spread spectrum architecture of the LTC3251 provides highly efficient and low noise operation. The burst and superburst operating modes also reduce operating current at light load conditions. The circuit has a low external parts count and requires only four small surface mount capacitors. DC 506 demonstrates appropriate layout techniques for the LTC3251 Inductorless DC-DC converter. This power supply circuit is ideally suited for space-constrained battery-powered applications that require small size and low operating current. Design files for this circuit board are available. Call the LTC factory. QUICK START PROCEDURE Demonstration circuit DC506 is easy to set up to evaluate the performance of the LTC3251. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: NOTE: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the VIN or VOUT and GND terminals. See Figure 2 for proper scope probe technique. 1. With power off, connect input power source to VIN and GND terminals. Input voltage range is limited to between 3.2V and 5.5V. 2. Place operation mode selector jumper JP1 in the GND position, JP2 in the VIN position for Burst Mode operation. 3. Connect load between the VOUT and GND terminals. 4. Turn on the power at the input. NOTE: Make sure that the input voltage does not exceed 5.5V. 5. Check for the proper output voltages. VOUT = 1.5V. If there is no output, temporarily disconnect the load to make sure that the load is not set too high. 6. Once the proper output voltages are established, adjust the loads up to 500mA and observe the output voltage regulation, input and output ripple voltage, efficiency and other parameters. NOTE: IOUT derates linearly to 200mA for VIN less than 3.5V. 7. For continuous mode operation, set opera- tion mode selector jumper JP1 in the VIN position, JP2 in the GND position. Please refer Table1 for other modes of operation. Table 1. Modes of Operation: JP1 JP2 MODE GND GND SHUTDOWN GND VIN BURST VIN GND CONTINUOUS VIN VIN SUPER BURST 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC CONVERTER – + + + + – + – – – + LOAD – F Figure 4. Input Ripple (VIN = 3.5V, IOUT = 500mA), 20MHz Bandwidth GND VIN Figure 1. Proper Measurement Equipment Setup Figure 2. Scope Probe Placement for Measuring Input or Output Ripple Figure 5. 1.5V Output Ripple (VIN = 3.5V, IOUT = 500mA), 20MHz Bandwidth F 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC CONVERTER 3 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC CONVERTER 4 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC 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 5 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC 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 6 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC 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 7 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC CONVERTER 8 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 506 500MA SPREAD-SPECTRUM,LOW NOISE,INDUCTORLESS STEP DOWN DC/DC CONVERTER 9 5 4 3 2 1 D D GND VIN 3 CIN2 1uF 10V 0603 JP1 2 GND JP2 2 R3 10M 1 GND CIN1 10uF,6.3V 0805 E3 MD0 GND R4 10M U1 C MD0 MD0 1 VIN 2 C1+ 3 C1- 4 C1 1uF 10V 0603 5 MD0 VIN C1+ C1GND VIN 1 E2 VIN 3 VIN 3.2V-5.5V E1 R1 536K 1% FB FB 10 MD1 MD1 9 C2+ C2+ 8 VOUT VOUT 7 C2C2- 6 R2 475K 1% C C3 4.7pF MD1 VOUT C2 1uF 10V 0603 LTC3251EMSE COUT1 10uF 6.3V 1206 COUT2 1uF 6.3V 0603 GND E5 MD1 E6 VOUT=1.5V IOUT=500mA * E7 GND B B DERATES LINEARLY TO 200mA * IOUT FOR VIN LESS THAN 3.5V NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE INOHMS, 0402. ALL CAPACITORS ARE IN MICROFARADS, 0402. 2. INSTALL SHUNTS ON JP1 AND JP2 PIN 2AND 3. 3. THE MODES OF OPERATION: A CONTRACT NO. APPROVALS JP1 JP2 MODE GND VIN GND VIN GND GND VIN VIN SHUTDOWN BURST CONTINUOUS SUPER BURST DRAWN: TECHNOLOGY KIM T. CHECKED: TITLE: SCHEMATIC SIZE DWG NO. APPROVED: ENGINEER: RAYMOND Z. DESIGNER: 4 3 A 500mA SPREAD-SPECTRUM, LOW NOISE, INDUCTORLESS STEP DOWN DC/DC CONVERTER A DATE: 5 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only Friday, August 23, 2002 2 REV DC506A - LTC3251EMSE SHEET 1 1 A OF 1 BILL OF MATERIALS DC506A Linear Technology Corporation LTC3251EMSE 6/17/2005 12:54 PM 500mA SPREAD-SPECTRUM, LOW NOISE, INDUCTORLESS STEP DOWN DC/DC CONVERTER ENG: RAYMOND Z. Item Qty Reference 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 3 1 1 1 6 2 2 1 1 2 1 4 4 Part Description CIN1 CAP., X5R 10uF 6.3V, 0805 C1,C2,CIN2 CAP., X5R 1uF 10V,0603 COUT1 CAP., X5R 10uF 6.3V,1206 COUT2 CAP., X5R 1uF 6.3V,0603 C3 CAP., NPO 4.7pF 50V,0402 E1,E2,E3,E5,E6,E7 TP, TURRET, .094" JP1,JP2 JMP, 1X3 PINS, .079 SHUNTS FOR JP1 AND JP2 SHUNT, 2 PINS, .079" R1 RES, 536K 1%, 0402 R2 RES, 475K 1%, 0402 R3,R4 RES, 10M 5%, 0402 U1 IC, LTC3251EMSE, MSE10 MTG HOLES AT 4 CORNERS STANDOFF, NYLON HEX #4-40 x 1/4" SCREW, #4-40 x 1/4 NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS, 0402. 2. INSTALL SHUNTS ON JP1 AND JP2 PIN 2 AND 3. 3. INSTALL 4 STANDOFF COMPONENTS ON BOTTOM SIDE. Page 1 - of - 1 Manufacture / Part # TAIYO YUDEN, JMK212BJ106MG TAIYO YUDEN, LMK107BJ105MA TAIYO YUDEN, JMK316BJ106ML TAIYO YUDEN, JMK107BJ105MA AVX, 04025A4R7CAT MILL-MAX, 2501-2 COMM CON, 2802S-03G2 COMM CON, CCIJ2mm-138G AAC, CR05-5363FM AAC, CR05-4753FM AAC, CR05-106JM LINEAR TECH., LTC3251EMSE MICRO PLASTICS, #14HTSP101 ANY