DC1829A

DEMO MANUAL DC1829A LTC3866EUF High Efficiency Step-Down Converter with Very Low DCR Inductor DESCRIPTION Demonstration circuit 1829A is a high efficiency, high density, synchronous buck converter with 4.5V to 14V input voltage range. It can supply a 30A maximum load current with a 1.5V output. This demo board utilizes the LTC®3866EUF, a feature-rich single phase synchronous buck controller with very low DCR current sensing capability, on-chip drivers and remote output voltage sensing. This board is setup with 0.32mΩ DCR inductor. The temperature compensation function guarantees accurate current limit over a wide temperature range with DCR sensing. To shut down the converter, set the RUN pin voltage below 1.2V (JP2: OFF). Use JP1 jumper to select Burst Mode® operation, pulse skipping mode or forced continuous mode operation at light load. Switching frequency is preset at about 400kHz, and it can be easily modified from 250kHz to 770kHz. Onboard dynamic circuit is also available for transient test. Please see LTC3866 data sheet for more detailed information. The LTC3866 is suitable for operation from an input voltage of 4.5V to 38V and output voltages up to 3.5V. It can provide high efficiency, high power density and versatile power solutions for telecom and datacom systems, industrial and medical instruments, along with DC power distribution systems and computer systems. The LTC3866 is available in 24-pin 4mm × 4mm QFN and 24-lead FE packages. L, LT, LTC, LTM, μModule, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY PARAMETER Design files for this circuit board are available at http://www.linear.com/demo (TA = 25°C) CONDITION Input Voltage Range VALUE 4.5V to 14V Output Voltage, VOUT VIN = 4.5V to 14V, IOUT = 0A to 30A 1.5V ±2% Maximum Output Current, IOUT VIN = 4.5V to 14V, VOUT = 1.5V 30A Typical Efficiency VIN = 12V, VOUT = 1.5V, IOUT = 30A 90.3% Typical Switching Frequency 400kHz dc1829af 1 DEMO MANUAL DC1829A QUICK START PROCEDURE Demonstration circuit 1829A is easy to set up to evaluate the performance of the LTC3866EUF. Refer to Figure 1 for the proper measurement equipment setup and follow the procedure below: 5. Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, ripple voltage and other parameters. 1. With power off, connect the input power supply to VIN (4.5V to 14V) and GND (input return). Note: When measuring the output or input voltage ripple, do not use the long ground lead on the oscilloscope probe. See Figure 2 for the proper scope probe technique. Short, stiff leads need to be soldered to the (+) and (–) terminals of an output capacitor. The probe’s ground ring needs to touch the (–) lead and the probe tip needs to touch the (+) lead. 2. Connect the 1.5V output load between VOUT and GND (Initial load: no load). 3. Connect the DVMs to the input and outputs. Set default jumper position: JP1: CCM; JP2: ON. 4. Turn on the input power supply and check for the proper output voltages. VOUT should be 1.5V ±2%. Figure 1. Proper Measurement Equipment Setup dc1829af 2 DEMO MANUAL DC1829A QUICK START PROCEDURE Figure 2. Measuring Output Voltage Ripple Efficiency Test at CCM 96 94 EFFICIENCY (%) 92 90 88 86 84 82 80 VIN = 4.5V VIN = 12V VIN = 14V 78 76 0 5 10 20 15 LOAD CURRENT (A) 25 30 dc1829a F03 Figure 3. Efficiency vs Load Current Load Regulation at VIN = 12V 1.7 OUTPUT VOLTAGE (V) 1.5 1.3 1.1 0.9 0.7 0.5 0 10 20 30 LOAD CURRENT (A) 40 dc1829a F04 Figure 4. Output Voltage vs Load Current dc1829af 3 DEMO MANUAL DC1829A QUICK START PROCEDURE Top View Bottom View L QB QT 3866 dc1829a F05a dc1829a F05b Figure 5. Thermal Performance at VIN = 14V, VO = 1.5V, IO = 30A, No Forced Air, TA = 25°C VSW (200mV/DIV) VP-P = 331mV IO (20A/DIV) IO = 0A TO 25A t (50μs/DIV) dc1829a F06 Figure 6. Transient Performance at VIN = 12V, VO = 1.5V, IO = 0A ~ 25A dc1829af 4 DEMO MANUAL DC1829A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 CIN1, CIN2 CAP, 180μF 20% 16V SANYO 16SVP180MX 2 2 CIN3, CIN4 CAP, 1210 10μF 20% 25V X5R TAIYO YUDEN TMK325BJ106MM-T 3 2 COUT1, COUT2 CAP, 7343 330μF 20% 2.5V POSCAP SANYO 2R5TPE330M9 4 4 COUT3, COUT6, C15, C16 CAP, 1210 100μF 20% 6.3V X5R TDK C3225X5R0J107M 5 2 C19, C21 CAP, 0603 1μF 10% 25V X5R TAIYO YUDEN TMK107BJ105MA-T 6 2 C22, C27 CAP, 0603 220nF 10% 25V X7R TDK C1608X7R1E224K 7 2 C24, C25 CAP, 0603 0.1μF 10% 10V X5R AVX 0603ZD104KAT 8 1 C26 CAP, 0603 1.5nF 5% 50V C0G MURATA GRM1885C1H152JA01D 9 1 C28 CAP, 0603 220pF 10% 25V NPO AVX 06033A221KAT2A 10 1 C31 CAP, 0805 4.7μF 20% 10V X5R TDK C2012X5R1A475M 11 1 D2 DOIDE, CMDSH-3 CENTRAL SEMI CMDSH-3 12 1 L1 IND, 0.33μH WURTH ELEKTRONIK M744301033 13 1 Q1 XSTR, POWER MOSFET INFINEON BSC050NE2LS 14 1 Q3 XSTR, POWER MOSFET INFINEON BSC010NE2LS 15 1 Q5 XSTR, SUD50N03-09P MOSFET SILICONIX SUD50N03-09P 16 5 R9, R32, R34, R36, R44 RES, 0603 0Ω JUMPER 1/10W VISHAY CRC06030000Z0EA 17 1 R10 RES, 0603 100k 5% 1/10W VISHAY CRCW0603100KJNEA 18 1 R11 RES, 0603 10k 5% 1/10W VISHAY CRCE060310K0JNEA 19 1 R12 RES, 2512 0.010Ω 5% 1W VISHAY WSL2512R0100FEA 20 1 R27 RES, 0603 100k 1% 1/10W VISHAY CRCW0603100KFKEA 21 1 R28 RES, 0603 1k 1% 1/10W VISHAY CRCW06031K00FKEA 22 1 R30 RES, 0603 931Ω 1% 1/10W YAGEO RC0603FR-07931RL 23 2 R31, R45 RES, 0603 10Ω 5% 1/10W VISHAY CRCW060310R0JNEA 24 1 R37 RES, 0603 2.2Ω 5% 1/10W VISHAY CRCW06032R20JNEA 25 1 R38 RES, 0603 20k 1% 1/10W VISHAY CRCW060320K0FKEA 26 1 R39 RES, 0603 30.1k 1% 1/10W VISHAY CRCW060330K1FKEA 27 1 R40 RES, 0603 10k 1% 1/10W VISHAY CRCW060310K0FKEA 28 1 R42 RES, 0603 3.01k 1% 1/10W VISHAY CRCW06033K01FKEA 29 1 R43 RES, 0603 4.64k 1% 1/10W VISHAY CRCW06034K64FKEA 30 1 U1 IC, STEP-DOWN CONVERTER LINEAR TECH LTC3866EUF Additional Demo Board Circuit Components 1 0 COUT4, COUT5 CAP, 7343 330μF 20% 2.5V POSCAP OPTION SANYO 2R5TPE330M9 OPTION 2 0 C23, C29, C32, C33, C34 CAP, 0603 OPTION OPTION 3 0 Q2, Q4 XSTR, OPTION OPTION 4 0 RN1 THERMISTOR, OPTION OPTION 5 0 R1-R6, R35, R41, R47, R48 RES, 0603 OPTION OPTION 6 0 R18 RES, 2512 OPTION OPTION dc1829af 5 DEMO MANUAL DC1829A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Hardware/Components (For Demo Board Only) 1 13 E1, E2, E4-E8, E10-E15 TURRET MILL-MAX 2501-2-00-80-00-00-07-0 2 1 JP1 HEADER, 4 PIN SAMTEC TMM-104-02--L-S 3 1 JP2 HEADER, 3 PIN SAMTEC TMM-103-02--L-S 4 2 J1, J2 JACK, BANANA KEYSTONE 575-4 5 2 J3, J4 STUD, TEST PIN PEM KFH-032-10 6 4 J3, J4 NUT, BRASS PL #10-32 ANY, #10-32M/S 7 2 J3, J4 RING, LUG RING #10 KEYSTONE, 8205 8 2 J3, J4 WASHER, TIN, PLATED BRASS ANY 9 2 J5, J6 CONN, BNC, 5 PINS CONNEX 112404 10 4 MH1, MH2, MH3, MH4 STANDOFF, SNAP ON KEYSTONE_8833 11 2 JP1, JP2 SHUNT SAMTEC 2SN-BK-G dc1829af 6 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. A B C D E2 E1 E4 CLKOUT GND R9 0 C28 220pF E12 E11 5 CLKOUT C21 1uF R38 20k 1% C24 0.1uF 10V R32 0 C23 OPT RUN ON OFF 1 3 JP2 2 EXTVCC E10 R40 10k 1% C26 1.5nF EXTVCC TRK/SS RUN MODE/PLLIN R6 OPT R34 0 VOUT R41 OPT VOUT R5 OPT C29 OPT OPT C32 R39 30.1k 1% R35 OPT R2 OPT R1 OPT VIN 2 MODE/PLLIN P.S. BURST CCM 1 4 JP1 3 INTVCC 6 5 4 3 2 1 R10 100k 4 OPT OPT 12 13 14 15 16 17 18 ILIM CLKOUT BG SW TG BOOST INTVCC VIN EXTVCC RN1 OPT R47 OPT OPT R48 OPT C34 R28 1k 1% R42 3.01k 1% INTVCC R36 0 INTVCC C19 1uF EXTVCC INTVCC LTC3866EUF U1 ITEMP 100k 1% R27 TEMPERATURE COMPENSATION NETWORK FOR DCR SENSING ITEMP 220nF R4 C27 220nF R3 C22 SNSD+ DIFFP DIFFN DIFFOUT VFB ITH 4 SGND 25 PGOOD 24 TK/SS 23 RUN 22 FREQ SNS- 21 8 4 4 CUSTOMER NOTICE + COUT5 IOUT 330uF OPT 7343 1 C15 100uF 6.3V 1210 Q2 OPT 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. G J6 GND IOSTEP CLK R31 10 TECHNOLOGY E7 E15 VOUT C33 OPT COUT6 COUT3 100uF 100uF 6.3V 6.3V 1210 1210 VOUT CIN2 180uF 16V + R45 10 COUT1 330uF 2.5V 7343 + + VOUT GND GND 4.5V ~ 14V VIN E13 VO_SNS- VO_SNS+ E14 GND COUT2 1.5V / 30A 330uF 2.5V 7343 J4 J3 E6 CIN1 180uF 16V J2 VIN JIAN L. APPROVED 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only + J1 E5 DATE 07/27/11 1 PROTO VIN REVISION HISTORY DESCRIPTION Monday, December 12, 2011 DATE: 1 SHEET DEMO CIRCUIT 1829A PCB NO. N/A LTC3866EUF IC NO. SIZE 1 OF 1 2 REV HIGH EFFICIENCY STEP-DOWN CONVERTER WITH VERY LOW DCR INDUCTOR TITLE: SCHEMATIC R11 10K 1 R43 R44 4.64k 0 1% DCR=0.32mOHM Q5 SUD50N03-09P R18 OPT 2512 2 CIN3 10uF 25V 1210 L1 0.33uH 2 REV 744301033 CIN4 10uF 25V 1210 ECO CONTRACT NO. R12 0.010 2512 S D R30 931 1% Q4 OPT 2 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A APPROVALS CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. MI VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL ENG. JIAN L. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. + COUT4 330uF OPT 7343 VOUT 4 Q3 BSC010NE2LS SW 4 Q1 BSC050NE2LS VIN VOUT C16 100uF 6.3V 1210 J5 INTVCC LOAD STEP CIRCUIT CMDSH-3 D2 C25 0.1uF 10V VIN C31 4.7uF 10V 0805 R37 2.2 3 5 5 2 1 7 MODE/PLLIN SNSA+ 19 ITEMP 20 PGOOD ILIM 9 CLKOUT 10 PGND 11 5 1 2 3 5 1 2 3 1 2 3 5 1 2 3 5 4 3 2 2 3 4 5 E8 A B C D DEMO MANUAL DC1829A SCHEMATIC DIAGRAM dc1829af 7 DEMO MANUAL DC1829A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc1829af 8 Linear Technology Corporation LT 1211 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2011