DEMO MANUAL DC1755A LTC3860EUH Wide Input Range, High Efficiency Step-Down DC/DC Converter DESCRIPTION Demonstration circuit DC1755A provides the user with two high current dual phase synchronous buck converters driven by the LTC3860. These buck converters provide outputs of 1.5V/50A and 1.2V/50A over an input voltage range of 6V to 14V and a switching frequency of 500kHz. The board can be easily modified for a 4-phase, single VO, 100A supply. The power stage for each phase consists of the tri-state PWM compatible 6mm × 6mm Fairchild DrMOS module and a 0.47μH 13.2mm × 12.8mm iron powder type inductor from Würth. A high density, two sided drop-in layout is used. The entire converter, excluding the bulk output and input capacitors, fits within a 2.25” × 1.38” area on the board. 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. PERFORMANCE SUMMARY PARAMETER The main features of the board are listed below: • High efficiency and high current density. • Remote sensing for each output. • Optional resistors to tie the two outputs together. • Connector and header to tie two or more boards together for up to 12-phase operation. • RUN, PGOOD and TRACK/SS pins for each output. • CLKIN and CLKOUT pins. • Onboard bias voltage regulator. • BNC connectors to monitor each output voltage. Design files for this circuit board are available at http://www.linear.com/demo (TA = 25°C), no airflow. CONDITIONS VALUE Minimum Input Voltage 6V Maximum Input Voltage 14V Output Voltage VOUTA IOUTA = 0A to 50A, VIN = 6V to 14V 1.5V ± 2% Output Voltage VOUTB IOUTB = 0A to 50A, VIN = 6V to 14V 1.2V ± 2% VOUTA Maximum Output Current, IOUTA VIN = 6V to 14V, VOUTA = 1.5V 50A VOUTB Maximum Output Current, IOUTB VIN = 6V to 14V, VOUTB = 1.2V Nominal Switching Frequency 50A 500kHz Efficiency VOUTA = 1.5V, IOUTA = 50A, VIN = 12V 90.2% Typical See Figures 2 and 3 VOUTB = 1.2V, IOUTB = 50A, VIN = 12V 89.2% Typical dc1755af 1 DEMO MANUAL DC1755A QUICK START PROCEDURE Demonstration circuit 1755A is easy to set up to evaluate the performance of the LTC3860EUH. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below. 1) With power off, connect the input supply, load and meters as shown in Figure 1. Preset the load to 0A and VIN supply to be 0V. Place jumpers in the following positions: JP1 JP2 JP3 RUNA RUNB INT PWR BLK BIAS ON ON ON 2) Adjust the input voltage to be between 6V to 14V. VOUTA should 1.5V ± 2%. Note 3. Do not apply the load from the VOSA+ turret to the VOSA– turret or from the VOSB+ turret to the VOSB– turret. These turrets are only intended to monitor the voltage across COUT3 and COUT13 respectively. Heavy load currents applied across these turrets may damage the converter. DYNAMIC LOAD CIRCUIT (OPTIONAL) Demonstration circuit 1755A provides a simple load step circuit consisting of a MOSFET and sense resistor for each rail. To apply a load step, follow the steps below. 1) Preset the amplitude of a pulse generator to 0.0V and the duty cycle to 5% or less. 3) Next, apply 50A load to each output and remeasure VOUT. 2) Connect the scope to the VOUT BNC connectors for the rail under test with a coax cable. To monitor the load step current, connect the scope probe across the ISTEP+– turrets for that rail. 4) Once the DC regulation is confirmed, observe the output voltage ripple, load step response, efficiency and other parameters. 3) Connect the output of the pulse generator to the PULSE GEN turret for the rail under test and connect the return to one of the GND turrets. Note 1. No airflow is required at room temperature with 50A on both outputs. But for ambient temperatures higher than 30°C, a cooling fan is recommended. 4) With the converter running, slowly increase the amplitude of the pulse generator output to provide the desired load step pulse height. The scaling for the load step signal is 10mV/A. VOUTB should 1.2V ± 2%. Note 2. Use the BNC connectors labeled VOUTA or VOUTB to measure the output voltage ripple. dc1755af 2 DEMO MANUAL DC1755A QUICK START PROCEDURE + IOUTA - VOUTA load - VOUTB load A + IOUTB A + VOUTA * + V V - VOUTB - * + V VIN - DC1755a F01 IIN * A + VIN supply Monitor voltage across COUT7 and COUT19 for accurate efficiency measurements. - Figure 1. Proper Measurement Equipment Setup dc1755af 3 DEMO MANUAL DC1755A 95 95 90 90 EFFICIENCY (%) EFFICIENCY (%) QUICK START PROCEDURE 85 80 80 VIN = 6V VIN = 10V VIN = 12V VIN = 14V 75 0 10 20 30 40 50 85 VIN = 6V VIN = 10V VIN = 12V VIN = 14V 75 60 0 10 20 LOAD CURRENT (A) 30 40 50 DC1755a F02 Figure 2. Efficiency Curves for the 1.5V Rail of the DC1755A 1.5VO (AC) 50mV/DIV 77mV DC1755a F03 Figure 3. Efficiency Curves for the 1.2V Rail of the DC1755A 1.2VO (AC) 50mV/DIV 81mV 50A LOAD STEP 10A/DIV 60 LOAD CURRENT (A) 50A LOAD STEP 10A/DIV 25A 20μs/DIV DC1755a F04 Figure 4. Load Step Response of the 1.5V Rail SINGLE OUTPUT/4-PHASE OPERATION A single output/4-phase converter may be preferred for higher output current applications. The optional components required to tie the phases together are found on sheet 3 of the schematic in the lower right hand corner. To tie the two outputs together, make the following modifications: 1) Select one rail to be the master. a) If VOUTA is the master, then stuff 0Ω at R103 to disable the error amplifier for VOUTB. b) If VOUTB is the master, then stuff 0Ω at R104 to disable the error amplifier for VOUTA. 25A 20μs/DIV DC1755a F05 Figure 5. Load Step Response of the 1.2V Rail 2) Stuff 0Ω at R87, R88, R89 and R91 to tie the IAVG, COMP, TRACK/SS and RUN signals together. 3) Remove the redundant compensation components. 6-PHASE AND 12-PHASE OPERATION Two or more boards may be tied together for up to 12-phase operation. To parallel two or more boards, place the boards side by side. Connect J9 of one board to J10 of the adjacent board (see sheet 3 of the schematic, lower right hand corner). This will tie the IAVG, COMP, TRACK/SS and dc1755af 4 DEMO MANUAL DC1755A QUICK START PROCEDURE RUN signals of the adjacent boards together. Next, locate the exposed copper shapes on the four corners of the board on the top and bottom layers. Use these shapes to tie the VOUT, VIN and GND planes of the adjacent boards. Next, select which phases will be the master or the slave. Figure 6 shows the typical setup for a 6-phase + 2-phase converter. Figure 7 shows the typical setup for a 12-phase converter. For additional help and support, contact your local LTC sales office. TOP 6 PHASE CONVERTER Cu Cu BOARD #1 BOARD #2 BOARD #1 = MASTER R87, R88, R89, R91 = 0 R101, R102 = 0.0m R103 = 0 R104 = NOT STUFFED 2 PHASE CONVERTER BOARD #2 BOARD #2 SIDE A = SLAVE SIDE B = INDEPENDENT DUAL PHASE RAIL R87, R88, R89, R91 = NOT STUFFED R101, R102 = NOT STUFFED R103 = NOT STUFFED R104 = 0 6 PHASE CONVERTER GND BOTTOM Cu BOARD #1 GND Cu DC1755a F06 Figure 6. Typical Setup for a 6-Phase + 2-Phase Converter dc1755af 5 DEMO MANUAL DC1755A QUICK START PROCEDURE TOP Cu Cu Cu BOARD #1 Cu BOARD #2 BOARD #1 = MASTER R87, R88, R89, R91 = 0 R101, R102 = 0.0m R103 = 0 R104 = NOT STUFFED BOARD #3 BOARD #2 = SLAVE R87, R88, R89, R91 = 0 R101, R102 = 0.0m R103, R104 = 0 BOARD #3 = SLAVE R87, R88, R89, R91 = 0 R101, R102 = 0.0m R103, R104 = 0 BOTTOM BOARD #3 GND Cu BOARD #2 Cu GND Cu BOARD #1 GND Cu DC1755a F07 Figure 7. Typical Setup for a 12-Phase Converter dc1755af 6 DEMO MANUAL DC1755A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CIN1 CAP, 180μF 20% 16V OSCON SANYO 16SVP180MX 2 4 CIN3, CIN5, CIN7, CIN9 CAP, 1210 22μF 20% 16V X5R TDK C3225X5R1C226M 3 12 COUT1 to COUT3, COUT4 to COUT6, COUT11 to COUT13, COUT14 to COUT16 CAP, 7343 330μF 20% 2.5V POSCAP SANYO 2R5TPE330M9L 4 8 COUT7 to COUT10, COUT17 to COUT20 CAP, 1206 100μF 20% 6.3V X5R MURATA GRM31CR60J107ME39L 5 2 C1 to A, C1 to B CAP, 0603 470pF 10% 25V NPO AVX 06033A471KAT2A 6 8 C1, C8, C9, C10, C13, C20, C21, C22 CAP, 0603 0.22μF 10% 25V X7R TDK C1608X7R1E224K 7 8 C2, C11, C14, C23, C31, C32, C33, C34 CAP, 0603 2.2μF 10% 16V X7R MURATA GRM188R61C225KE15 8 2 C4, C16 CAP, 0603 100pF 5% 25V NPO AVX 06033A101JAT2A 9 2 C2 to A, C2 to B CAP, 0603 68pF 5% 25V NPO AVX 06033A680JAT2A 10 2 C3 to A, C3 to B CAP, 0603 2200pF 25V X7R MURATA GRM188R71E222MA01 11 3 C7, C19, C28 CAP, 0603 1μF 20% 25V X5R AVX 06033D105MAT2A 12 4 L1, L2, L3, L4 IND, 0.47μH 20% WÜRTH 744355147 13 1 RB to A RES, 0603 13.3k 1% 1/10W VISHAY CRCW060313K3FKEA 14 1 RB to B RES, 0603 20k 1% 1/10W NIC NRC06F2002TRF 15 19 R1, R11, R12, R16, R20, R25, R36, R45, R46, R50, R54, R55, R59, R62, R69, R112, R113, R116, R118 RES, 0603 0Ω JUMPER VISHAY CRCW06030000Z0EA 16 2 R1 to A, R1 to B RES, 0603 20k 1% 1/10W NIC NRC06F2002TRF 17 6 R2, R17, R37, R51, R57, R107 RES, 0603 1Ω 5% 1/10W VISHAY CRCW06031R00JNEA 18 2 R2 to A, R2 to B RES, 0603 6.8k 1% 1/10W VISHAY CRCW06036K80FKEA 19 2 R3 to A, R3 to B RES, 0603 523Ω 1% 1/10W VISHAY CRCW0603523RFKEA 20 9 R3, R4, R24, R26, R31, R38, R39, R61, R63 RES, 0603 10k 1% 1/10W VISHAY CRCW060310K0FKEA 21 2 R8, R43 RES, 0603 100k 5% 1/10W YAGEO RC0603JR-07100KL 22 4 R15, R33, R49, R70 RES, 0603 2.87k 1% 1/10W VISHAY CRCW06032K87FKEA 23 2 R18, R52 RES, 0603 59.0k 1% 1/10W VISHAY CRCW060359K0FKEA 24 4 R19, R21, R53, R56 RES, 0603 10Ω 1% 1/10W NIC NRC06F10R0TRF 25 2 R30, R67 RES, 0603 40.2k 1% 1/10W VISHAY CRCW060340K2FKEA 26 2 U1, U2 IC, DUAL OUTPUT BUCK CONVERTER LINEAR TECHNOLOGY LTC3860EUH 27 4 U3, U4, U5, U6 INTEGRATED MOSFET, DC/DC CONVERTER FAIRCHILD FDMF6707B Bias Supply and UVLO Circuit 1 1 C29 CAP, 0603 2.2μF 10% 16V X7R MURATA GRM188R61C225KE15 2 1 C25 CAP, 0603 1μF 20% 25V X5R AVX 06033D105MAT2A 3 1 C26 CAP, 0805 10μF 10% 25V NPO AVX 08053D106MAT2A 4 1 C27 CAP, 0603 0.1μF 10% 16V X7R AVX 0603YC104KAT2A 5 1 C30 CAP, 0603 10pF 5% 50V NPO MURATA GQM1885C1H100JB01 6 1 D1 DIODE, BAV170 SOT23 DIODES INC., BAV170 7 1 D2 DIODE SHOTTKY SOD326 NXP PMEG2005AEA 8 1 L5 INDUCTOR 27μH 20% WÜRTH 7447789127 9 1 R105 RES, 0603 20k 1% 1/10W NIC NRC06F2002TRF 10 1 R106 RES, 0603 10k 1% 1/10W VISHAY CRCW060310K0FKEA dc1755af 7 DEMO MANUAL DC1755A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 11 1 R90 RES, 1206 0Ω JUMPER VISHAY CRCW12060000Z0EA 12 1 R93 RES, 0603 100Ω 5% 1/10W VISHAY CRCW0603100RFKEA 13 1 R97 RES, 0603 105k 1% 1/10W VISHAY CRCW0603105KFKEA 14 1 R100 RES, 0603 127k 1% 1/10W VISHAY CRCW0603127KFKEA 15 1 U7 IC, STEP DOWN REGULATOR, DFN LINEAR TECHNOLOGY LT3502EDC 16 1 U8 IC, VOLTAGE MONITOR, DC-3 LINEAR TECHNOLOGY LT6703IDC-3 Additional Circuit Components 1 0 CIN2 CAP, SANYO SVP-F8 OPTIONAL 2 0 CIN4, CIN6, CIN8, CIN10 to CIN12 CAP, 1210 OPTIONAL 3 0 COUT21 to COUT26, COUT31 to COUT36 CAP, 7343H OPTIONAL 4 0 COUT27 to COUT30, COUT37 to COUT48 CAP, 1206 OPTIONAL 5 0 RES, 0603 R5, R6, R7, R9, R10, R13, R14, R23, R27, R28, R29, R32, R34, R35, R40, R41, R42, R44, R47, R48, R58, R60, R64, R65, R66, R68, R71, R72, R87, R88, R89, R91, R92, R94, R95, R96, R103, R104, R108, R110, R111, R114, R115, R117, R119 OPTIONAL 6 0 C3, C5, C6, C12, C15, C17, C18, C24 CAP, 0603 OPTIONAL 7 0 Q2, Q3 MOSFET, TO-252 OPTIONAL 8 0 R73, R74, R77, R78, R83, R84, R85, R86 RES, 0603 OPTIONAL 9 0 R80, R82, R101, R102 RES, 2010 OPTIONAL 10 2 Q1, Q4 MOSFET, TO-252 VISHAY SUD50N03-09P 11 2 R75, R76 RES, 0603 10k 1% 1/10W VISHAY CRCW060310K0FKEA 12 2 R79, R81 RES, 2010 0.010Ω 2% 1W IRC LRC-LRF2010LF-01-R010-F KEYSTONE 8831 Hardware/Components (For Demo Board Only) 1 4 STANDOFF, SNAP ON 2 12 NUT, BRASS #10-32 ANY 3 6 RING, LUG #10 KEYSTONE 8205 4 6 WASHER, TIN, PLATED BRASS ANY 5 24 E1 to E11, E14, E16, E17 to E27 TURRET MILL MAX 2501-2-00-80-00-00-07-0 6 3 JP1 to JP3 HEADER, 3 PIN SAMTEC TMM-103-02-L-S 7 3 XJP1 to XJP3 SHUNT, 2mm CTRS SAMTEC 2SN-BK-G 8 6 J1 to J4, J11, J12 STUD, TEST PIN PEM KFH-032-10 9 2 J7, J8 CON, BNC, 5 PINS CONNEX 112404 10 1 J9 HEADER, DOUBLE ROW, RIGHT ANGLE MILL-MAX 802-40-008-20-001000 11 1 J10 SOCKET, DOUBLE ROW MILL-MAX 803-43-008-20-001000 dc1755af 8 1 2 3 4 RB-A 13.3K 1% 3 E9 R32 OPT CLKINA R31 10k VCCA VCCA R110 OPT R29 OPT 8 7 6 5 4 3 2 1 VCCA FB2 COMP2 VSNSP VSNSN VSNSOUT COMP1 FB1 C12 OPT VIN R11 0 TRACK/SSA VCC C5 OPT VCCA R8 100K R34 OPT R30 40.2K VCCA C6 OPT A IAVGA R7 OPT U1 LTC3860EUH CLKOUTA FSWITCH = 500kHz TYPICAL VDIFA FBA C7 1uF R17 1 R14 OPT COMPA R2-A 6.8k C1-A 470pF R117 OPT E7 R12 0 VOB+ R10 OPT C3 OPT 5VBIAS R116 0 VOSA+ 68pF C2-A R3-A 523 C3-A 2200pF E4 E3 JP1 2 CAPACITORS AND RESISTORS ARE 0603 UNLESS OTHERWISE SPECIFIED. GND CLKINA VOSA- R1-A 20K 1% R112 0 VDIFA TRACK/SSA PGOODA OFF ON GND 33 31 VINSNS 32 TRK/SS1 30 CLKIN 11 TRK/SS2 9 28 CLKOUT 12 FREQ 10 SGND 29 SGND 27 IAVG R35 OPT 14 C4 100pF PWMEN2 RUN2 ILIM2 ISNS2P ISNS2N ISNS1N ISNS1P ILIM1 RUN1 PWMEN1 R13 OPT R9 OPT VCCA VIN PWM1 25 PGOOD1 PGOOD2 26 PWMEN1 PWMEN2 15 PWM2 16 PHSMD 13 OPT B R25 0 17 18 19 20 21 22 23 24 R18 59.0k R28 OPT R23 OPT VCCA R16 0 ILIMA B CIN6 OPT 1210 CIN3 22uF 16V 1210 CIN5 22uF 16V 1210 C9 0.22uF C8 0.22uF CIN4 OPT 1210 VIN 20 19 18 17 16 15 14 13 12 11 20 19 18 17 16 15 14 13 12 11 PGND PGND PGND PGND PGND VSWH VIN VIN VIN VIN PGND PGND PGND PGND PGND VSWH VIN VIN VIN VIN VIN PGND 0.22uF C1 C10 0.22uF C2 2.2uF 16V R1 0 C U3 FDMF6707B C11 2.2uF 16V R20 0 5VBIAS 1 5VBIAS U4 FDMF6707B C PHASES 1 AND 2 22 R6 PGND 23 RUNA PGND A 21 PGND 22 10 9 42 8 21 7 PGND 24 3 1 26 PGND 6 GH 10 9 42 8 VIN VIN VIN NC PGND 23 PGND 6 PHASE 7 24 PGND 25 5 41 GH PGND 25 4 DISB# VSWH VSWH VSWH VSWH VSWH GL CGND THWN VSWH VSWH VSWH VSWH VSWH GL CGND THWN DISB# PWM 31 32 33 34 35 36 37 38 39 40 DISBL#2 R26 10K THDN2 THDN1 R5 OPT R27 OPT DISBL#1 R4 10K CUSTOMER NOTICE C32 2.2uF 16V 31 32 33 34 35 36 37 38 39 40 C31 2.2uF 16V L1 0.47uH 744355147 WURTH EL. D THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. + AK SCALE = NONE MIKE S. COUT4 330uF 2.5V CIN11 OPT 1210 CIN2 OPT R21 10 COUT3 330uF 2.5V VOA+ R19 10 + + E8 E6 J4 COUT1 330uF 2.5V J3 E5 DATE 09-28-11 GND VOSA- GND VOUTA 1.5V / 50A VIN- GND VIN 6V - 14V VIN+ VOSA+ E2 J2 J1 E1 MIKE S APPROVED DATE: N/A SIZE LTC3860EUH E DEMO CIRCUIT 1755A Monday, January 16, 2012 IC NO. SHEET 1 OF 3 2 REV. DUAL OUTPUT 4 -PHASE STEP-DOWN CONVERTER 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only VOSA- COUT2 330uF 2.5V + VIN CIN1 180uF 16V VOSA+ + PRODUCTION + E DESCRIPTION REVISION HISTORY TECHNOLOGY COUT9 100uF 6.3V 1206 + 2 REV TITLE: SCHEMATIC COUT10 100uF 6.3V 1206 COUT5 330uF 2.5V COUT6 330uF 2.5V + COUT7 100uF 6.3V 1206 CIN12 OPT 1210 __ ECO COUT8 100uF 6.3V 1206 APPROVALS 0.47uH 744355147 WURTH EL. L2 R33 2.87K 1% R15 2.87K 1% D 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. R24 TP2 10K 1 R107 TP1 PWM R3 10K R2 CGND GND PGND 4 BOOT PGND 27 VIN VIN VIN NC PHASE 5 41 CGND GND 27 PGND 26 BOOT PGND 28 VDRV PGND 3 1 VCIN 2 VDRV PGND 28 SMOD# VSWH VSWH VSWH VCIN 2 43 29 30 1 SMOD# VSWH VSWH VSWH 43 29 30 RUNA 1 2 3 4 DEMO MANUAL DC1755A SCHEMATIC DIAGRAM dc1755af 9 1 2 3 4 RB-B 20.0K 1% E11 GND CLKOUTB E16 E14 R68 OPT VCCB R59 0 R119 OPT R118 0 R111 OPT C1-B 470pF R2-B 6.8k C15 OPT C24 OPT R66 OPT 8 7 6 5 FB2 COMP2 VSNSP VSNSN VSNSOUT COMP1 FB1 VCC VIN A CLKOUTB R45 0 U2 LTC3860EUH R67 40.2K VCCB IAVGB C18 OPT RUNB TRACK/SSB R43 100K VCCB FSWITCH = 500kHz TYPICAL VCCB VDIFB 4 3 2 1 VCCB C17 OPT C19 1uF FBB R48 OPT R51 1 R46 0 COMPB 5VBIAS VOSB+ 68pF C2-B R3-B 523 3 E10 JP2 C3-B 2200pF R69 0 CLKOUTA VOSB- R1-B 20K 1% R113 0 VDIFB TRACK/SSB PGOODB OFF 2 31 1 32 TRK/SS1 R72 OPT R71 OPT VIN ILIM1 RUN1 23 17 18 19 20 21 22 R62 0 R58 OPT R54 0 PWMEN4 RUNB RUN2 ILIM2 ISNS2P ISNS2N ISNS1N ISNS1P 24 R50 0 R47 OPT R44 OPT VCCB PWMEN3 100pF C16 R42 OPT R41 OPT 26 RUNB 33 GND VINSNS FREQ 10 CLKIN 11 TRK/SS2 9 30 SGND 28 IAVG 29 SGND CLKOUT 12 PHSMD 13 25 PWM1 27 PGOOD1 PGOOD2 14 PWMEN1 PWMEN2 15 ON B B R52 59.0k R65 OPT R60 OPT VCCB ILIMB CIN10 OPT 1210 C21 0.22uF C20 0.22uF CIN8 OPT 1210 CIN9 22uF 16V 1210 CIN7 22uF 16V 1210 VIN VIN 20 19 18 17 16 15 14 13 12 11 20 19 18 17 16 15 14 13 12 11 PGND PGND PGND PGND PGND VSWH VIN VIN VIN VIN PGND PGND PGND PGND PGND VSWH VIN VIN VIN VIN 21 21 PWM2 16 0.22uF C13 C 7 C14 2.2uF 16V R36 0 U5 FDMF6707B 0.22uF C22 C23 2.2uF 16V 0 R55 U6 FDMF6707B PGND 5VBIAS C 39 40 31 32 33 34 35 36 37 38 PWM DISB# DISBL#4 R63 10K DISBL#3 R39 10K THDN4 R64 OPT THDN3 R40 OPT CUSTOMER NOTICE 31 32 33 34 35 36 37 38 39 C34 2.2uF 16V C33 2.2uF 16V D L3 D THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. + SCALE = NONE MIKE S. AK APPROVALS 0.47uH 744355147 WURTH EL. L4 R70 2.87K 1% R49 2.87K 1% 0.47uH 744355147 WURST EL. 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. VSWH VSWH VSWH VSWH VSWH GL CGND THWN 40 R61 10K TP4 VSWH VSWH VSWH VSWH VSWH GL CGND THWN DISB# PWM R38 10K TP3 1 R37 5VBIAS 1 R57 PHASES 3 AND 4 23 PGND PHASE 10 9 42 8 VIN VIN VIN NC PGND 22 PGND 23 PGND 24 7 PHASE 10 9 42 8 VIN VIN VIN NC PGND 6 24 PGND 22 6 GH 5 41 CGND GND PGND 25 PGND 26 5 41 GH 2 CGND GND 26 PGND 3 PGND 4 BOOT 27 PGND 3 VDRV 28 PGND 2 VCIN PGND 25 1 VCIN 4 BOOT PGND 27 VDRV PGND 28 SMOD# VSWH VSWH VSWH 43 29 30 1 SMOD# VSWH VSWH VSWH 10 43 29 30 A + COUT14 330uF 2.5V TECHNOLOGY COUT12 330uF 2.5V VOSB- + VOSB+ E27 VOSB- GND VOUTB 1.2V / 50A VOSB+ COUT11 330uF 2.5V J12 + J11 E26 DATE: N/A SIZE LTC3860EUH E DEMO CIRCUIT 1755A Monday, January 16, 2012 IC NO. SHEET 2 OF 3 2 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only COUT13 330uF 2.5V R56 10 + VOB+ R53 10 DUAL OUTPUT 4 -PHASE STEP-DOWN CONVERTER TITLE: SCHEMATIC COUT19 100uF 6.3V 1206 + COUT17 100uF 6.3V 1206 COUT15 330uF 2.5V COUT20 100uF 6.3V 1206 COUT16 330uF 2.5V COUT18 100uF 6.3V 1206 E 1 2 3 4 DEMO MANUAL DC1755A SCHEMATIC DIAGRAM dc1755af 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. 1 2 3 4 COUT21 7343H OPT + COUT22 7343H OPT E25 ON OFF JP3 3 2 1 R75 10k 1 + COUT41 OPT 1206 VOA+ COUT24 7343H OPT R97 105K R105 20K 0 1206 R90 C30 10pF C25 1uF 5VBIAS A + COUT42 OPT 1206 COUT25 7343H OPT 1 + COUT43 OPT 1206 COUT26 7343H OPT E23 E19 R80 OPT 1% 2010 COUT44 OPT 1206 COUT27 OPT 1206 ISTEPA- 4 3 2 1 VIN SHDN FB BD VIN 1uF C28 C26 10uF L5 9 GND EXPOSED PAD GND DA BOOST SW U7 LT3502EDC 5 6 7 8 27uH WURTH EL.7447789127 J7 B C27 0.1uF 16V COUT28 OPT 1206 LOAD STEP 10mV / Amp ISTEPA+ Q2 SUD50N03-09P OPT BIA SUPPLY & UVLO CIRCUIT R114 OPT COUT23 7343H OPT + R79 0.010 1% 2010 OPTIONAL COUT E21 E17 INTERNAL BIAS VIN 5V / 400mA + VOA+ GND PULSE GEN A Q1 SUD50N03-09P 2 3 5% DUTY CYLCE MAX. 2 3 COUT30 OPT 1206 C29 2.2uF 16V VIN E22 E18 COUT31 7343H OPT COUT32 7343H OPT COUT45 OPT 1206 VOB+ + R76 10k RUNA RUNB R93 100 R106 10K R100 127K 1% 3 2 1 COUT33 7343H OPT COUT46 OPT 1206 + 1 GND 4 R96 R95 R94 R92 OPT OPT OPT OPT COUT34 7343H OPT COUT47 OPT 1206 + R81 0.010 1% 2010 1 C UVLO THRESHOLD = 5.5V RISING LT6703IDC-3 +INA VS OUT U8 R108 OPT D1 BAV170 SOT23 5VBIAS UVLO CIRCUIT R115 OPT + VOB+ GND PULSE GEN B Q4 SUD50N03-09P 5% DUTY CYLCE MAX. D2 PMEG4005AEA COUT29 OPT 1206 VOUTA C COUT48 OPT 1206 COUT35 7343H OPT THDN4 THDN3 THDN2 THDN1 + R82 OPT 1% 2010 + VOB+ CLKINA SGND SGND SGND RUNA TRACK/SSA COMPA IAVGA RIGHT ANGLE HEADER COUT37 OPT 1206 E24 E20 J8 1 8 7 6 5 4 3 2 IAVGA D COUT40 OPT 1206 R85 OPT PWMEN2 R77 OPT PWMEN1 OPT OPT OPT OPT R86 OPT R84 R83 PWMEN4 R74 R78 OPT PWMEN3 R73 DISBL#2 DISBL#1 PWM ENABLE CIRCUIT FOR NON-THREE STATE COMPATIBLE DRMOS E R102 OPT 2010 2010 VOB+ R101 OPT IAVGB COMPA OPT R88 R103 OPT D THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. AK MIKE S. SCALE = NONE 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. VCCA RUNB FBA MILL MAXX 803-43-008-20-001000 CLKOUTB SGND SGND SGND RUNB TRACK/SSB COMPB IAVGB 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only CONNECT TO PARALLEL DC1755A CLKOUTB 8 7 6 5 4 3 2 1 RIGHT ANGLE J10 SOCKET DISBL#4 DISBL#3 DATE: N/A SIZE LTC3860EUH E DEMO CIRCUIT 1755A Monday, January 16, 2012 IC NO. SHEET 3 OF 3 2 REV. DUAL OUTPUT 4 -PHASE STEP-DOWN CONVERTER TECHNOLOGY R104 OPT TITLE: SCHEMATIC FBB OPT R91 RUNA TRACK/SSA TRACK/SSB APPROVALS VCCB COMPB OPT R89 OPTIONAL COMPONENTS FOR SINGLE OUTPUT CONVERTER WITH 4,6 or 12 PHASES COUT39 OPT 1206 VOA+ OPT R87 COUT38 OPT 1206 ISTEPB- ISTEPB+ VOUTB CUSTOMER NOTICE CONNECT TO PARALLEL DC1755A CLKINA MILL MAXX 802-40-008-20-001000 J9 COUT36 7343H OPT LOAD STEP 10mV / Amp Q3 SUD50N03-09P OPT DYNAMIC LOAD CIRCUIT FOR VOUTB 2 VOA+ 1 2 3 DYNAMIC LOAD CIRCUIT FOR VOUTA B 3 2 3 A 1 2 3 4 DEMO MANUAL DC1755A SCHEMATIC DIAGRAM dc1755af 11 DEMO MANUAL DC1755A 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 dc1755af 12 Linear Technology Corporation LT 0112 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2012