DEMO MANUAL DC2142A LTC3875EUJ & LTC3874IUFD High Efficiency, Single-Output Synchronous Buck Converter with Very Low DCR Inductor Description Demonstration circuit 2142A is a high efficiency, high density, 4-phase synchronous buck converter with a 4.5V to 14V input range. It can supply 120A maximum load current at a 1.0V output. This demo board incorporates the LTC3875EUJ and LTC3874IUFD controllers. The LTC 3875 is a feature-rich dual phase synchronous buck controller with very low DCR current sensing capability, on-chip drivers and remote output voltage sensing. The LTC3874 is a compact dual phase synchronous buck phase extender with very low DCR current sensing capability, on-chip drivers and immediate response to master IC's fault. ® 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. The DC2142 can provide high efficiency, high power density and compact solutions for telecom and datacom systems, Performance Summary PARAMETER industrial and medical instruments, DC power distribution systems and computer systems. The LTC3875 is available in a 40-pin 6mm × 6mm QFN package. The LTC3874 is available in a 28-lead (4mm × 5mm) QFN Package. To shut down the converter, set the RUN pin voltage below 1.4V (SW1: OFF). Use the JP1 jumper to select burst mode, 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. An on-board dynamic circuit is also available for transient test. The LTC3875 and LTC3874 data sheets give a complete description of these parts, and must be read in conjunction with this DC2142A quick start guide Design files for this circuit board are available at http://www.linear.com/demo/DC2142A 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 VALUE Output Voltage, VOUT VIN = 4.5V to 14V, IOUT1 = 0A to 120A 1.0V ±2% Maximum Output Current, IOUT VIN = 4.5V to 14V, VOUT1 = 1.0V 120A Typical Efficiency, VOUT VIN = 12V, VOUT1 = 1.0 V, IOUT1 = 120A 87.4% Input Voltage Range Typical Switching Frequency 4.5V to 14V 400kHz dc2142af 1 DEMO MANUAL DC2142A Quick Start Procedure Demonstration circuit 2142A is easy to set up to evaluate the performance of the LTC3875EUJ and LTC3874IUFD. 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 1.0V 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; SW1: ON. 4.Turn on the input power supply and check for the proper output voltages. VOUT should be 1.0V ±2%. 2 dc2142af DEMO MANUAL DC2142A Quick Start Procedure + – VOUT + – – + + + – – 1mΩ + LOAD (0A ~ 120A) VIN 4.5V TO 14V – dc2142a F01 Figure 1. Proper Measurement Equipment Setup + VOUT – C40 GND Figure 2. Measuring Output Voltage Ripple dc2142af 3 DEMO MANUAL DC2142A Quick Start Procedure Efficiency vs Load Current, VOUT = 1.0V 95 EFFICIENCY (%) 90 85 80 75 70 0 20 40 60 80 100 120 LOAD CURRENT (A) dc2142a F03 Figure 3. Efficiency vs Load Current at VIN = 12V, VOUT = 1.0V, fSW = 400kHz Figure 4. Thermal Performance at VIN = 12V, VOUT = 1.0V, IOUT = 120A, 200PFM Forced Air Flow 4 dc2142af DEMO MANUAL DC2142A Quick Start Procedure Current Sharing vs Load Current, VOUT = 1.0V 35 CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNEL 4 CURRENT SHARING (A) 30 ±3.6% 25 20 15 10 5 0 0 20 40 60 80 100 120 LOAD CURRENT (A) dc2142a F05 Figure 5. Current Sharing vs Load Current at VIN = 12V, VOUT = 1.0V, fSW = 400kHz VOUT (20MHz BW) [5mV/DIV] Figure 6. Output Voltage Ripple at VIN = 12V, VOUT = 1.0V, IOUT = 120A dc2142af 5 DEMO MANUAL DC2142A Quick Start Procedure VOUT (20MHz BW) [20mV/DIV] 30A TO 60A LOAD STEP Figure 7. Transient Performance at VIN = 12V, VOUT = 1.0V, IOUT = 30A ~ 60A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 8 CIN1, CIN2, CIN3, CIN4, CIN5, CIN6, CIN7, CIN8 CAP, 1210, 10µF, 20%, 35V X5R AVX 1210DD106MAT2A 2 14 COUT1, COUT2, COUT6, COUT7, COUT9, COUT12, COUT13, COUT14, COUT19, COUT20, COUT24, COUT25, C39, C40 CAP, 1210, 100µF, 20%, 6.3V X5R TDK C3225X5R0J107M 3 12 COUT3, COUT4, COUT5, COUT8, COUT10, COUT11, COUT15, COUT16, COUT17,COUT18, COUT22, COUT23 CAP, 7343, 330µF, 20%, 6.3V POSCAP SANYO 6TPF330M9L 4 3 C3, C25, C29 CAP, 0603, 1µF, 20%, 25V X5R AVX 06033D105KAT2A 5 2 C1, C2 CAP, 270µF, 20%, 16V OSCON PANASONIC 16SVPC270M 6 4 C4, C30, C31, C46 CAP, 0603, 4.7µF, 10%, 10V X5R AVX 0603ZD475KAT2A 7 1 C5 CAP, 0603, 10nF, 10%, 16V X7R AVX 0603YC103KAT2A 8 5 C7, C8, C18, C32, C36, CAP, 0603, 0.1µF, 10%, 25V X5R AVX 06033C104KAT2A 9 6 C10, C12, C20, C24, C33, C35 CAP, 0603, 220nF, 10%, 25V X7R TDK C1608X7R1E224K 10 1 C15 CAP, 0603, 220pF, 5%, 50V C0G AVX 06035A221JAT2A 11 1 C16 CAP, 0603, 2.2nF, 5%, 50V C0G MURATA GRM1885C1H222JA01D 12 1 C34 CAP, 0603, 100pF, 10%, 16V X7R AVX 0603YC101KAT2A 13 1 D1, D2, D3, D4 DIODE, SCHOTTKY 30V, 100mA CENTRAL SEMI CMDSH-3-TR 14 4 L1, L2, L3, L4 IND, 0.25µH WÜRTH ELEKTRONIK 744301025 6 dc2142af DEMO MANUAL DC2142A Parts List ITEM QTY 15 4 REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Q1, Q5, Q10, Q15 XSTR, POWER MOSFET INFINEON BSC050NE2LS 16 4 Q3, Q7, Q13, Q17 XSTR, POWER MOSFET INFINEON BSC010NE2LSI 17 1 Q19 XSTR, N-CHANNEL DMOS FET FAIRCHILD 2N7002A 18 2 Q20, Q21 XSTR, MOSFET, N-CHANNEL 30V VISHAY SUD50N04-8M8P-4GE3 19 1 R1 RES, 0603, 20kΩ, 5%, 1/10W VISHAY CRCW060320K0JNEA 20 1 R2 RES, 0603, 3.01kΩ, 1%, 1/10W VISHAY CRCW06033K01FKEA 21 1 R3 RES, 0603, 1kΩ, 5%, 1/10W VISHAY CRCW06031K00JNEA 22 3 R4, R51, R85 RES, 0603, 2.2Ω, 5%, 1/10W VISHAY CRCW06032R20JNEA 23 2 R6, R14 RES, 0603, 10Ω, 1%, 1/10W VISHAY CRCW060310R0FKEA 24 4 R8, R28, R58, R66 RES, 0603, 715Ω, 1%, 1/10W VISHAY CRCW0603715RFKEA 25 2 R9, R27 RES, 0603, 3.57kΩ, 1%, 1/10W VISHAY CRCW06033K57FKEA 26 13 R10, R13, R24, R50, R53, R54, R56, R57, R59, R60, R61, R65, R67 RES, 0603, 0Ω, JUMPER VISHAY CRCW06030000Z0EA 27 1 R12 RES, 0603, 13.3kΩ, 1%, 1/10W VISHAY CRCW060313K3FKEA 28 1 R17 RES, 0603, 20kΩ, 1%, 1/10W VISHAY CRCW060320K0FKEA 29 1 R21 RES, 0603, 4.02kΩ, 1%, 1/10W VISHAY CRCW06034K02FKEA 30 3 R33, R42, R69 RES, 0603, 100kΩ, 1%, 1/10W VISHAY CRCW0603100KFKEA 31 1 R45 RES, 0603, 5kΩ, 5%, 1/10W VISHAY CRCW06035K00JNED 32 2 R46, R47 RES, 0603, 10kΩ, 1%, 1/10W VISHAY CRCW060310K0FKEA 33 1 R63 RES, 0603, 75kΩ 5% 1/10W VISHAY CRCW060375K0JNEA 34 1 R102 RES, 0603, 237kΩ, 1%, 1/10W VISHAY CRCW0603237KFKEA 35 1 SW1 SWITCH, SUBMINATURE SLIDE C&K JS202011CQN 36 1 U1 IC, DUAL, 2-PHASE, SYNCHRONOUS REGULATORS LINEAR TECH. LTC3875EUJ#PBF-ES 37 1 U2 IC, POLYPHASE STEP-DOWN SYNCHRONOUS SLAVE CONTROLLER LINEAR TECH. LTC3874IUFD#PBF CAP, 1210 OPTION OPTION Additional Demo Board Circuit Components 1 0 COUT27, COUT28, COUT29, COUT30, COUT31, COUT32, COUT33, COUT34, COUT35, COUT36, COUT37, COUT38, COUT39, COUT40, COUT41, COUT42, COUT43, COUT44, COUT45, COUT46 2 0 C9, C11, C26, C27, C28 CAP, 0603 OPTION OPTION 3 4 C43, C44, C47, COUT21, CAP, 0603, 1µF, 20%, 25V X5R AVX 06033D105KAT2A 4 1 C37 CAP, 0805, 10µF, 10%, 16V X5R MURATA GRM21BR61C106KE15L 5 1 C38 CAP, 0805, 22µF, 10%, 10V X5R TDK C2012X5R1A226K 6 1 C42 CAP, 0603, 150pF, 5%, 50V NPO AVX 06035A151JAT2A 7 2 C41, C45 CAP, 0603, 0.1µF, 10%, 25V X5R AVX 06033C104KAT2A 8 1 C48 CAP, 0603, 22pF, 2%, 50V C0G MURATA GRM1885C1H220GA01D 9 1 D5 DIODE, SCHOTTKY 30V, 100mA CENTRAL SEMI CMDSH-3-TR 10 1 L5 IND, 3.3µH WÜRTH ELEKTRONIK 744043003 dc2142af 7 DEMO MANUAL DC2142A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 11 0 Q2, Q4, Q6, Q8, Q11, Q14, Q16, Q18 XSTR, POWER MOSFET OPTION OPTION 12 2 R88, R92 RES, 0603, 20kΩ, 5% 1/10W VISHAY CRCW060320K0JNEA 13 2 R68, R87 RES, 0603, 0Ω, JUMPER VISHAY CRCW06030000Z0EA 14 0 RN1, RN2 THERMISTOR, OPTION OPTION 15 0 R5, R7, R11, R15, R16, R18, R19, R34, R35, R37, R39, R40, R41, R43, R44, R48,R49, R52, R55, R62, R64, R70, R76, R101, R104, R105 RES, 0603 OPTION OPTION 16 2 R77, R94 RES, 0603, 10kΩ, 1% 1/10W VISHAY CRCW060310K0FKEA 17 1 R80 RES, 0603, 187kΩ, 1% 1/10W VISHAY CRCW0603187KFKEA 18 1 R83 RES, 0603, 23.2kΩ, 1% 1/10W VISHAY CRCW060323K2FKEA 19 1 R89 RES, 0603, 3.3Ω, 1%, 1/10W VISHAY CRCW06033R30FNEA 20 1 R90 RES, 0603, 154kΩ, 1% 1/10W VISHAY CRCW0603154KFKEA 21 1 R91 RES, 0603, 1MΩ, 5% 1/10W VISHAY CRCW06031M00JNEA 22 1 R93 RES, 0603, 681kΩ, 1% 1/10W VISHAY CRCW0603681KFEA 23 2 R95, R100 RES, 0603, 301Ω, 1% 1/10W VISHAY CRCW0603301RFKEA 24 1 R96 RES, 0603, 82.5Ω, 5% 1/10W VISHAY CRCW060382R5FKEA 25 2 R97, R98 RES, 2512, 0.01Ω, 1% 1W VISHAY WSL2512R0100FEA 26 1 R99 RES, VARIABLE 5k BOURNS 3386P-1-502-LF 27 1 UD1 IC, OSCILLATOR WITH SPREAD SPECTRUM MODULATION LINEAR TECH. LTC6908S6-1#PBF 28 1 U3 IC, 17V, 1A, SYNCHRONOUS STEP-DOWN REGULATOR LINEAR TECH. LTC3621EDCB-2#PBF 29 1 U4 IC, VOLTAGE-CONTROLLED PULSE WIDTH MODULATOR LINEAR TECH. LTC6992IS6-1 30 1 U5 IC, SINGLE OP AMP LINEAR TECH. LT1803IS5 MILL MAX 2501-2-00-80-00-00-07-0 Hardware: For Demo Board Only 1 12 E1, E2, E3, E4, E5, E6, E7, E11, E13, E14, E15, E16 TURRET 2 1 JP1 HEADER, 4-PIN WURTH 620 004 111 21 3 2 JP6, JP7 HEADER, SINGLE ROW 3-PIN WURTH 620 003 111 21 4 6 J1, J2, J3, J4, J5, J6 STUD, TEST PIN PEM KFH-032-10 J7, J9 5 2 6 6 7 4 MH1, MH2, MH3, MH4 CONN, BNC, 5-PINS CONNEX 112404 LUG RING, #10 KEYSTONE 8205 STANDOFF, SNAP ON KEYSTONE 8834 8 12 NUT, BRASS 10-32 ANY #10-32 9 6 WASHER, #10 TIN PLATED BRASS ANY #10 EXT BZ TN 10 3 SHUNT WURTH 608 002 134 21 8 JP1, JP6, JP7 dc2142af J1 OPT RN1 ITH VO_SNS- VFB VO_SNS+ TK/SS TK/SS RUN RUN VIN- GND J2 4.5V - 14V VIN VIN+ RUN TK/SS R40 OPT 0 OPT R44 + C1 270uF 16V R10 VO_SNS- VFB E6 E5 E4 E2 OPT C26 R11 OPT 0.1uF C7 R4 2.2 + C2 270uF 16V VIN OPT RN2 RUN 5 ON OPT R48 C16 2.2nF OPT C27 2 OPT R7 OPT C28 VIN R45 5k MODE BM CCM 4 C5 10nF OPT R5 PS 2 1 JP1 3 R1 20K SW1 OPT C11 C9 OPT OFF R43 OPT 4.02k 1% R21 C15 220pF R17 20k 1% R12 13.3k 1% C3 1.0uF 4 1 6 3 PLLIN 2 1 R46 10K 1% 36 14 13 12 37 16 8 7 6 5 4 3 2 1 34 R47 10K 1% R33 100k 1% TRSET1 TRSET2 TAVG TCOMP2 TCOMP1 RUN2 TKSS2 VOSNS2- VOSNS2+ ITH2 ITH1 VOSNS1- VOSNS1+ TK/SS1 RUN1 4.7uF EXTVCC R3 1k INTVCC1 4.7uF C4 C46 26 VIN LTC3875EUJ U1 R41 OPT R2 3.01k 1% INTVCC1 OPT R19 INTVCC1 R37 OPT ISNS2- SNSA2+ SNSD2+ BG2 BOOST2 SW2 TG2 SNS1- SNSD1+ SNSA1+ BG1 BOOST1 SW1 TG1 BST2 BG2 22 23 10 9 R39 OPT C20 220nF SW2 11 TG2 20 C12 220nF 21 39 38 40 27 BG1 28 BST1 30 SW1 29 TG1 OPT R105 220nF C24 R18 OPT R13 0 R34 OPT R24 0 220nF C10 INTVCC1 4 Q6 OPT Q4 OPT 4 Q8 OPT 4 CUSTOMER NOTICE Q7 BSC010NE2LSI 4 4 Q2 OPT 5 CIN1 10uF 1210 CIN3 10uF 1210 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. R35 OPT CMDSH-3-TR 0.1uF D2 C18 4 VIN Q3 BSC010NE2LSI 4 Q5 BSC050NE2LS OPT R16 INTVCC1 R15 OPT CMDSH-3-TR 0.1uF D1 C8 4 Q1 BSC050NE2LS VIN 5 1 2 3 INTVCC1 17 32 PHASMD 5 1 2 3 E1 2 1 24 EXTVCC IFAST 25 INTVCC FREQ 15 35 ILIM SGND/PGND 41 33 MODE/PLLIN ENTMPB 18 31 CLKOUT PGOOD 19 5 1 2 3 5 1 2 3 5 1 2 3 5 1 2 3 1 2 3 5 1 2 3 EXTCLK L1 0.25uH R28 715 1% !" SCALE = NONE COUT6 100uF 6.3V 1210 VO_SNS- COUT2 100uF 6.3V 1210 C25 1.0uF EXTVCC COUT5 + 330uF 6.3V 7343 R14 10 1% COUT3 + 330uF 6.3V 7343 DATE E14 12/31/13 DATE: N/A SIZE GND EXTVCC GND PGOOD PGOOD E13 E11 J6 SHEET 1 LTC3875EUJ / LTC3874EUFD DEMO CIRCUIT 2142A Tuesday, December 31, 2013 IC NO. VOUT VO_SNS- GND VOUT VO_SNS+ 1.0V AT 120A J5 E7 J4 J3 E3 CLKOUT Y INGY I, Y . APPROVED 3 OF 3 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only COUT8 + 330uF 6.3V 7343 COUT4 + 330uF 6.3V 7343 TECHNOLOGY R42 100k 1% INTVCC1 COUT7 100uF 6.3V 1210 VOUT COUT1 100uF 6.3V 1210 VOUT VO_SNS+ R6 10 1% REVISION HISTORY PROD DESCRIPTION TITLE: SCHEMATIC HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR 744301025 DCR=0.32m OHM L2 R9 3.57k 1% APP ENG. #"$%#"&#' PCB DES. 0.25uH 3 REV 744301025 DCR=0.32m OHM APPROVALS R27 3.57k 1% CIN4 10uF 1210 R8 715 1% CIN2 10uF 1210 ECO DEMO MANUAL DC2142A Schematic Diagram dc2142af 9 TK/SS R49 R53 0 OPT R55 R52 OPT INTVCC2 R54 0 INTVCC2 R56 0 OPT R50 0 COUT17 COUT18 + 330uF + 330uF 6.3V 6.3V 7343 7343 VOUT R67 0 INTVCC2 OPT R64 PGOOD ITH RUN PGOOD CLKOUT EXTCLK COUT19 100uF 6.3V 1210 0 COUT20 100uF 6.3V 1210 R63 75k 100pF C34 R61 R60 0 R57 0 13 11 10 27 9 28 5 4 8 1 12 COUT21 1.0uF PHASMD ILIM FREQ LOWDCR ITH1 ITH0 RUN1 RUN0 MODE1 MODE0 SY NC 1.0uF 20 U2 4.7uF C30 C39 100uF 6.3V 1210 Q19 2N7002A BST3 BG3 22 21 BST4 BG4 16 17 3 0 25 26 6 COUT25 100uF 6.3V 1210 COUT24 100uF 6.3V 1210 R69 100k 1% INTVCC2 C35 220nF SW4 15 7 TG4 14 3 C33 220nF SW3 23 2 TG3 24 R68 FAULT1B FAULT0B ISENSE1- ISENSE1+ BG1 BOOST1 SW1 TG1 ISENSE0- ISENSE0+ BG0 COUT22 COUT23 + 330uF + 330uF 6.3V 6.3V 7343 7343 2 SW0 TG0 BOOST0 4.7uF C31 LTC3874IUFD#PBF R51 2.2 C40 100uF 6.3V 1210 VIN EXTVCC 18 EXTVCC C29 19 INTVCC GND 29 R59 0 R65 0 4 Q16 OPT Q14 OPT 4 Q18 OPT 4 CIN6 10uF 1210 CIN7 10uF 1210 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE Q17 BSC010NE2LSI 4 4 Q11 OPT 5 CIN8 10uF 1210 CIN5 10uF 1210 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. INTVCC2 4 VIN Q13 BSC010NE2LSI 4 Q15 BSC050NE2LS CMDSH-3-TR 0.1uF D4 C36 CMDSH-3-TR INTVCC2 0.1uF D3 C32 4 Q10 BSC050NE2LS VIN 5 INTVCC2 1 5 5 1 2 3 5 1 2 3 5 1 2 3 1 2 3 5 1 2 3 1 2 3 1 2 3 5 10 1 2 3 VIN L3 0.25uH 0.25uH OPT OPT !" SCALE = NONE APP ENG. #"$%&"'#( PCB DES. APPROVALS R70 R66 715 1% 744301025 L4 R62 R58 715 1% 744301025 COUT15 + 330uF 6.3V 7343 COUT10 + 330uF 6.3V 7343 TECHNOLOGY COUT14 100uF 6.3V 1210 COUT9 100uF 6.3V 1210 VOUT DATE: N/A SIZE SHEET 2 LTC3875EUJ / LTC3874EUFD DEMO CIRCUIT 2142A Wednesday, March 05, 2014 IC NO. 2 OF 3 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only COUT16 + 330uF 6.3V 7343 COUT11 + 330uF 6.3V 7343 TITLE: SCHEMATIC HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR COUT13 100uF 6.3V 1210 COUT12 100uF 6.3V 1210 DEMO MANUAL DC2142A Schematic Diagram dc2142af 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. ON R92 20K 1 OPT R104 154k 2 0.1uF 3 2 1 R77 10K 1% C45 OFF3 R90 BIAS JP6 C37 10uF 16V 0805 INTVCC1 VIN D5 2 6 5 SET GND MOD DIV V+ OUT 4 5 6 VIN MODE INTVCC U4 LTC6992IS6-1 C47 1.0uF 25V R102 237k 1% R93 681K 1% R91 R87 1M 0 RUN FB SW L5 3.3uH C43 1.0uF R100 301 1% R95 301 1% 0.1uF R101 OPT R88 20K C41 744043003 +5.5V R99 5K 3 4 1 UD1 LTC6908S6-1#PBF 1 6 V+ OUT1 2 5 GND OUT2 3 4 SET MOD 70Hz, 3% Duty Cy cle CMDSH-3-TR GND 7 +5.5V U3 LTC3621EDCB-2 OPTIONAL 5.5V BIAS R83 23.2K 1% R80 187k 1% +IN V- V+ -IN VOUT U5 LT1803IS5 EXTCLK 3 2 5 C48 22pF 4 1 C38 22uF 10V 0805 EXTVCC 82.5 1% R96 COUT27 OPT 1210 COUT38 OPT 1210 COUT28 OPT 1210 COUT39 OPT 1210 COUT29 OPT 1210 R98 0.01 2512 SUD50N04-8M8P-4GE3 Q20 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE R97 0.01 2512 Q21 2 J9 2 J7 !" SCALE = NONE APP ENG. #"$%&"'#( PCB DES. COUT43 OPT 1210 DATE: N/A SIZE SHEET 3 LTC3875EUJ / LTC3874EUFD DEMO CIRCUIT 2142A Wednesday, March 05, 2014 IC NO. 2 OF 3 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR TECHNOLOGY COUT36 OPT 1210 COUT46 OPT 1210 COUT35 OPT 1210 COUT45 OPT 1210 COUT34 OPT 1210 COUT44 OPT 1210 COUT33 OPT 1210 VOUT IOUT STEP VOUT COUT42 OPT 1210 COUT32 OPT 1210 APPROVALS GND C44 1.0uF 1 1 COUT41 OPT 1210 COUT31 OPT 1210 E16 VOUT COUT40 OPT 1210 COUT30 OPT 1210 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. R85 2.2 SUD50N04-8M8P-4GE3 DYNAMIC LOAD CIRCUIT COUT37 OPT 1210 VOUT EXT PULSE E15 R94 10K 1% INT EXT JP7 PULSE 2 3.3 1% 1 3 OPT R76 C42 150pF R89 +5.5V VOUT DEMO MANUAL DC2142A Schematic Diagram dc2142af 11 DEMO MANUAL DC2142A 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 12 Linear Technology Corporation dc2142af LT 0314 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2014