DEMO MANUAL DC2000A LTC3875EUJ High Efficiency, Dual-Output Synchronous Buck Converter with Very Low DCR Inductor Description Demonstration circuit 2000A is a high efficiency, high density, synchronous buck converter with a 4.5V to 14V input range. It can supply 30A maximum load current at a 1.0V output and at a 1.5V output separately. The demo board includes a LTC®3875EUJ controller. The LTC3875 is a feature-rich dual phase synchronous buck controller with very low DCR current sensing capability, on-chip drivers and remote output voltage sensing. This board is set up with a 0.32mΩ DCR inductor. The temperature compensation function can guarantee accurate current limit over a wide temperature range with DCR sensing. The LTC3875 is suitable for inputs from 4.5V to 38V and outputs up to 3.5V. It can provide a high efficiency, high power density and versatile power solution for telecom and datacom systems, industrial and medical instruments, DC Performance Summary PARAMETER power distribution systems and computer systems. The LTC3875 is available in a 40-pin 6mm × 6mm QFN package. To shut down the converter, set the RUN1/RUN2 pin voltage below 1.2V (SW1: OFF; SW2: OFF). Use the JP1 jumper to select burst mode, pulse-skipping mode or forced continuous mode operation at light load. Switching frequency is pre-set at about 400kHz, and it can be easily modified from 250kHz to 770kHz. An on-board dynamic circuit is also available for the transient test. Please see the LTC3875 data sheet for more detailed information. Design files for this circuit board are available at http://www.linear.com/demo/DC2000A L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C CONDITIONS Input Voltage Range VALUE 4.5V to 14V Output Voltage, VOUT1 VIN = 4.5V to 14V, IOUT1 = 0A to 30A 1.0V ±2% Maximum Output Current, IOUT1 VIN = 4.5V to 14V, VOUT1 = 1.0V Typical Efficiency, VOUT1 VIN = 12V, VOUT1 = 1.0 V, IOUT1 = 30A 86.9% Output Voltage, VOUT2 VIN = 4.5V to 14V, IOUT2 = 0A to 30A 1.5V ±2% Maximum Output Current, IOUT2 VIN = 4.5V to 14V, VOUT2 = 1.5V Typical Efficiency, VOUT2 VIN = 12V, VOUT2 = 1.5V, IOUT2 = 30A Typical Switching Frequency 30A 30A 89.6% 400kHz dc2000af 1 DEMO MANUAL DC2000A Quick Start Procedure Demonstration circuit 2000A is easy to set up to evaluate the performance of the LTC3875EUJ. Refer to Figure 1 for the proper measurement equipment setup and follow the procedure below: 1.With power off, connect the input power supply to VIN (4.5V to 14V) and GND (input return). 2.Connect the 1.0V output load between VOUT1 and GND (Initial load: no load). 3.Connect the 1.5V output load between VOUT2 and GND (Initial load: no load). 4.Connect the DVMs to the input and outputs. Set default jumper position: JP1: CCM; SW1: ON; SW2: ON. 2 5.Turn on the input power supply and check for the proper output voltages. VOUT1 should be 1.0V ±2%. And VOUT2 should be 1.5V ±2% 6.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. 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. dc2000af DEMO MANUAL DC2000A Quick Start Procedure - + V 1mΩ + Vout1 - Load (30A) + + Load (30A) - Vout2 VIN + 4.5V-‐14V V 1mΩ V + - - - + V A V - Figure 1. Proper Measurement Equipment Setup + VOUT – COUT GND Figure 2. Measuring Output Voltage Ripple dc2000af 3 DEMO MANUAL DC2000A 100 100 90 90 EFFICIENCY (%) EFFICIENCY (%) Quick Start Procedure 80 40 60 50 5 15 10 20 LOAD CURRENT (A) 25 40 60 4.5VIN 12VIN 0 80 30 DC2000A F03 Figure 3. Efficiency vs Load Current at VOUT1 = 1V 50 4.5VIN 12VIN 0 5 15 10 20 LOAD CURRENT (A) 25 30 DC2000A F04 Figure 4. Efficiency vs Load Current at VOUT2 = 1.5V Figure 5. Thermal Performance at VIN = 12V, VOUT1 = 1V, IOUT1 = 30A, VOUT2 = 1.5V, IOUT2 = 30A, No Forced Air 4 dc2000af DEMO MANUAL DC2000A Quick Start Procedure VOUT1 20MHz BW 50mV/DIV VOUT2 20MHz BW 5mV/DIV 5µs/DIV DC2000A F06 5µs/DIV Figure 6. Output Voltage Ripple at VIN = 12V, VOUT1 = 1V, IOUT1 = 30A Figure 7. Output Voltage Ripple at VIN = 12V, VOUT2 = 1.5V, IOUT2 = 30A VOUT1 20MHz BW 50mV/DIV VOUT2 20MHz BW 50mV/DIV 0A TO 15A LOAD STEP 0A TO 15A LOAD STEP 100µs/DIV DC2000A F08 Figure 8. Transient Performance at VIN = 12V, VOUT1 = 1V, IOUT1 = 0A to 15A DC2000A F07 100µs/DIV DC2000A F09 Figure 9. Transient Performance at VIN = 12V, VOUT2 = 1V, IOUT2 = 0A to 15A dc2000af 5 DEMO MANUAL DC2000A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER SANYO, 16SVPC270M Required Circuit Components 1 1 CIN1 CAP., OS-CON, 270µF, 16V, 20%, E12 2 6 CIN2, CIN3, CIN4, CIN5, C27, C28 CAP., X5R, 10µF,16V, 10%, 1210 3 2 C10, C20 CAP., X5R, 10µF,16V, 10%, 0805 4 6 COUT1, COUT3, COUT7, COUT8, C29, C33 CAP., X5R, 100µF, 6.3V, 20%,1210 5 7 COUT2, COUT4, COUT5, COUT6, COUT9, COUT10, COUT11 CAP., OS-CON, 330µF, 16V, 20%, 7343 6 4 C2, C7, C18, C21 CAP., X5R, 0.1µF, 16V, 10%, 0603 7 4 C3, C4, C16, C19 CAP., X5R, 220nF, 25V, 10%, 0603 8 2 C8, C12 CAP., X5R, 1.5nF, 25V, 10%, 0603 SANYO, 2R5TPE330M9 9 1 C9 CAP., X5R, 220pF, 25V, 10%, 0603 10 1 C11 CAP., X5R, 150pF, 25V, 10%, 0603 11 2 C13, C22 CAP., X5R, 1µF, 16V, 10%, 0603 12 1 C14 CAP., X5R, 4.7µF, 16V, 10%, 0805 13 4 C31, C32, C35, C36 CAP., X5R, 0.22µF, 16V, 10%, 0805 14 2 D1, D2 DIODE, SCHOTTKY, SOD-323 CENTRAL CMDSH-3TR 15 1 L1 0.25µH WÜRTH ELECT., 744301025 16 1 L2 0.33µH WÜRTH ELECT., 744301033 17 2 Q1, Q3 OPTIMOS POWER-TRANSISTOR, PG-TDSON-8 25V INFINEON, BSC050NE2LS 18 2 Q2, Q4 OPTIMOS POWER-TRANSISTOR, PG-TDSON-8 25V INFINEON, BSC010NE2LSI 19 2 Q7, Q8 MOSFET SPEED SRS 30V 30A LFPAK RENESAS RJK0305DPB 20 3 R1, R14, R25 RES., CHIP, 20k, 1%, 0603 21 4 R4, R17, R23, R26 RES., CHIP, 0Ω, 0603 22 1 R9 RES., CHIP, 3.01k, 1%, 0603 23 1 R10 RES., CHIP, 1k, 1%, 0603 24 1 R11 RES., CHIP, 3.57k, 1%, 0603 25 1 R12 RES., CHIP, 715Ω, 1%, 0603 26 1 R13 RES., CHIP, 13.3k, 1%, 0603 27 7 R19, R37, R40, R49, R52, R55, R57 RES., CHIP, 10k, 1%, 0603 28 1 R15 RES., CHIP, 10.7k, 1%, 0603 29 4 R16, R20, R24, R36 RES., CHIP, 10Ω, 1%, 0603 30 1 R18 RES., CHIP, 2.2Ω, 1%, 0603 31 1 R21 RES., CHIP, 30.1k, 1%, 0603 32 1 R50 RES., CHIP, 34.8k, 1%, 0603 33 2 R28, R32 RES., CHIP, 100k, 1%, 0603 34 1 R34 RES., CHIP, 4.64k, 1%, 0603 35 1 R35 RES., CHIP, 931Ω, 1%, 0603 36 1 R43 RES., CHIP, 4.99k, 1%, 0603 37 2 R56, R58 RES., CHIP, 0.005Ω, 1%, 2512 6 IRC., LRF2512-01-R005-F dc2000af DEMO MANUAL DC2000A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 38 1 U1 IC, LTC3875EUJ, QFN 6mm × 6mm LINEAR TECH., LTC3875EUJ#010J-1PBF 39 1 U2 IC, LT1761ES5-SD, TSOT-23 LINEAR TECH., LT1761ES5-SD Additional Demo Board Circuit Components 1 0 C1, C5, CIN6, C6, CIN7, C30, C34, CIN8, CAP., OPTIONAL CIN9, CIN10, CIN11, C15, C17, C23, C24, C25, C26, COUT12 2 0 RN1-RN4, R2, R3, R5 , R6, R7, R8, R22, R27, R29, R33, R30, R31, R38, R39, R41, R42, R44, R45, R46, R47, R48, R51, R53, R54 RES., OPTIONAL 3 0 Q5, Q6, Q11, Q12 DUAL N-CHANNEL MOSFET 25V FAIRCHILD FDMS3620S 4 0 Q9, Q10 DUAL N-CHANNEL MOSFET 25V FAIRCHILD FDPC8011S dc2000af 7 A B C GND EXTVCC TRK/SS2 R15 10.7K 1% E5 RN1 OPT 5 R38 OPT C26 OPT R43 5k R40 10k C22 1uF EXTVCC R37 10k TCOMP1 TAVG TRSET2 VO2_SNS- R29 OPT R26 0 R41 OPT C21 0.1uF 1% R19 10K C11 150pF VO1_SNS- C23 OPT VOUT1 R25 20k C17 OPT C15 OPT RN4 OPT VFB2 ITH2 ITH1 R14 20k R13 13.3k TK/SS1 RUN1 R21 30.1k R30 OPT C12 1.5nF C2 0.1uF R3 OPT VO1_SNS+ C1 OPT R2 OPT RN2 OPT E3 R1 R39 OPT R42 OPT 4 C24 OPT TK/SS2 5 R31 OPT OPT 220nF C19 SGND/PGND SNS2- SNSA2+ TK/SS2 VOSNS2- VOSNS2+ ITH2 ITH1 VOSNS1- VOSNS1+ R8 OPT C4 4 220nF JP1 TK/SS1 R27 41 10 9 8 7 6 4 ITH2 3 2 1 220nF C3 OPT R5 1 MODE PS BM CCM 3 4 2 ITH1 TK/SS1 20K R22 C16 OPT 220nF VFB1 TCOMP2 TK/SS2 C6 OPT C5 OPT PLLIN INTVCC R7 OPT RUN1 TCOMP1 U1 LTC3875EUJ 5 OFF ON SW2 RUN2 R32 100K 1% 2 C25 OPT 4 D1 TG2 R44 OPT 3 3 ON VIN JP3 ENTMPB 1 OFF 2 INTVCC BG2 SW2 0.1uF 0 C18 21 20 R23 22 23 24 BG2 SW2 TG2 BG1 SW1 TG1 CMDSH-3 D2 2.2 C13 1uF CMDSH-3 0.1uF 25 0 C7 INTVCC R18 EXTVCC BG1 R17 TG1 SW1 CLKOUT 3.01K R9 JP2 26 27 28 100K PGOOD R45 OPT RUN2 30 29 R28 SW2 TG2 BOOST2 BG2 EXTVCC INTVCC VIN BG1 BOOST1 TG1 SW1 ILIM 1 R10 1K INTVCC PHASMD 120 90 60 DEG DEG DEG 3 2 VIN VO2_SNS+ 0 R6 OPT R4 2 C9 220pF TRSET1 RN3 OPT E13 E12 E10 C8 1.5nF TRK/SS1 2 1 D ON 5 OFF 4 1 6 3 SW1 RUN1 2 1 3 E1 2 1 TRSET1 RUN1 2 1 40 SNSA1+ 39 SNS1- 11 SNSD2+ 38 12 SNSD1+ 37 TCOMP1 36 TAVG 13 TAVG TCOMP2 TCOMP2 34 ILIM 35 TRSET1 15 FREQ 16 TRSET2 14 TRSET2 4 1 6 3 32 RUN1 RUN2 33 MODE/PLLIN 17 IFAST IFAST 31 PHASMD 10V BG2 SW2 TG2 BG1 SW1 TG1 OPT R33 Q1 BSC050NE2LS 4 4 CIN3 10uF 1210 4 R11 3.57k 1% CIN4 10uF 1210 Q3 BSC050NE2LS VIN R34 4.64k 1% Q4 BSC010NE2LSI CIN5 10uF 1210 Q2 BSC010NE2LSI CIN2 10uF 1210 CUSTOMER NOTICE 4 VIN 2 L1 2 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 2 REV SCALE = NONE JIAN L. HZ APPROVALS CIN12 270uF 16V VOUT2 R24 10 R36 10 2.5V 7343 2.5V 7343 TECHNOLOGY VOUT1 E14 E15 DATE: N/A SIZE 1 DEMO CIRCUIT 2000A LTC3875EUJ Thursday, October 03, 2013 IC NO. C VO2_SNS+ VO1_SNS- GND 1.0V / 30A E11 J6 D VO1_SNS+ VIN- GND PGOOD RUN2 SHEET 1 2 REV. OF 2 A B VO2_SNS- GND VOUT2 1.5V / 30A J5 E9 E8 J4 J3 E7 E6 J2 4.5V - 14V VIN 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only VO2_SNS- C20 10uF 10V VOUT2 VO2_SNS+ COUT6 + 330uF C10 10uF 10V VOUT1 VO1_SNS- COUT5 + 330uF 330uF 2.5V 7343 + J1 E4 VIN+ JIAN L. VIN DATE 9-30-13 APPROVED VO1_SNS+ CIN1 270uF 16V + COUT4 R20 10 330uF 2.5V 7343 R16 10 + PRODUCTION HIGH EFFICIENCY, DUAL-OUTPUT SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR TITLE: SCHEMATIC 1 DESCRIPTION REVISION HISTORY + COUT2 VIN COUT8 100uF 6.3V 1210 COUT1 100uF 6.3V 1210 COUT7 100uF 6.3V 1210 COUT3 100uF 6.3V 1210 __ ECO SET R33=60K ohm FOR FAST TRANSIST RESPONSE @ VOUT2 R35 931 1% 0.33uH 744301033 DCR = 0.32m OHM L2 0.25uH 744301025 DCR = 0.32m OHM R12 715 1% LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. INTVCC C14 4.7uF INTVCC VIN INTVCC E2 CLKOUT 5 6 7 8 1 2 3 5 6 7 8 1 2 3 CLKOUT PGOOD 19 ENTMPB 18 ENTMPB 5 6 7 8 1 2 3 5 6 7 8 1 2 1 2 8 1 2 3 5 DEMO MANUAL DC2000A Schematic Diagram dc2000af 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 ITH2 VO2_SNS- VFB2 RUN1 TK/SS1 R53 OPT R54 OPT SW1 3 6 4 7 SW1 BG1 TG1 5 7 1 Q9 FDPC8011S, OPT 9 Q11 FDMS3620S OPT 2 5 8 1 BG1 TG1 9 SW2 Q12 FDMS3620S OPT 4 3 2 CIN8 OPT VIN SW2 BG2 TG2 7 1 Q10 FDPC8011S, OPT 4 OPTIONAL 3mm x 3mm Dual-MOSFETs 8 1 Q5 FDMS3620S OPT CIN6 OPT 2 5 CIN10 OPT 3 6 VIN 4 7 OPTIONAL 5mm x 6mm Dual-MOSFETs 8 5 C OPT R51 OPT R48 8 5 RUN2 TK/SS2 4 3 2 VIN 3 6 CIN9 OPT 8 1 FOR DUAL PHASE OPERATION, REMOVE R24, R36, R21, R25, AND SHORT VOUT1 AND VOUT2. ITH1 R46 OPT 9 6 2 5 D VO1_SNS- VFB1 9 9 6 BG2 TG2 CIN11 OPT 8 1 CIN7 OPT VIN 3 Q6 FDMS3620S OPT 3 OFF JP5 BIAS ON C27 10uF 16V + CUSTOMER NOTICE 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. VIN J8 COUT10 330uF 7343 2 R49 10K IOUT1 + 1 IOUT2 J10 2 SCALE = NONE JIAN L. HZ APPROVALS C36 0.22uF TECHNOLOGY R58 0.005 2512 4 R57 10K R55 10K 1 1 C28 10uF 16V J7 OPT R47 J9 E19 E18 IO1STEP CLK GND IO2STEP CLK VOUT2 GND E17 E16 VOUT1 EXTVCC 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only C35 0.22uF R56 0.005 2512 4 C31 0.22uF R52 10K R50 34.8K 1% +5.5V 1 DATE: N/A SIZE 1 DEMO CIRCUIT 2000A LTC3875EUJ Thursday, October 03, 2013 IC NO. SHEET 2 OF 2 2 REV. HIGH EFFICIENCY, DUAL-OUTPUT SYNCHRONOUS BUCK TITLE: SCHEMATIC 1 RJK0305DPB Q8 C34 OPT 6.3V 1210 C32 0.22uF RJK0305DPB Q7 C30 OPT 6.3V 1210 4 LT1761ES5-SD 5 OUT SHDN ADJ GND IN U2 C29 100uF 6.3V 1210 3 2 1 COUT11 COUT12 C33 + 100uF 330uF OPT 6.3V 7343 7343 1210 LOAD STEP CIRCUIT 2 VOUT2 + COUT9 330uF 7343 LOAD STEP CIRCUIT 1 VOUT1 2 OPTIONAL 5.5V BIAS VIN LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 6 4 7 10 2 5 4 7 4 9 3 1 5 10 5 4 3 2 5 4 3 2 5 3 2 1 5 3 2 1 2 3 4 5 2 3 4 5 OPTIONAL JUMPERS FOR SINGLE OUTPUT/DUAL PHASE OPERATION A B C D DEMO MANUAL DC2000A Schematic Diagram dc2000af 9 DEMO MANUAL DC2000A 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 10 Linear Technology Corporation dc2000af LT 1213 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013