DEMO MANUAL DC1998A LTC3892 60V, Low IQ Dual Output High Voltage Step-Down Converter Description Demonstration circuit 1998A is a high input voltage, high efficiency synchronous dual output buck converter featuring the LTC®3892. The DC1998A has a wide input voltage range of 6V to 60V. The output voltages are set to 5V and 12V, however, the output voltage can be set almost as high as the input voltage (≤99% • VIN), with certain modifications. This demo board is capable of delivering up to 8A from the 5V output and up to 5A from the 12V output. The DC1998A supports three operation modes: forced continuous mode, pulse-skipping and Burst Mode® operation. Forced continuous mode, reduces output voltage ripple and yields a low noise switching spectrum. Burst Mode operation employs a variable frequency switching algorithm that minimizes the no-load input quiescent current and improves efficiency at light loads. The DC1998A consumes less than 4µA of quiescent current during shutdown and below 0.15 mA no-load quiescent current when in Burst Mode operation with an input voltage above 14V. However, if Ch2 is in shutdown and Ch1 in sleep mode, the quiescent current can be as low as 29µA. The DC1998A has a fixed operating frequency Performance Summary PARAMETER of 200kHz and can be adjusted to frequencies between 50kHz and 900kHz. The DC1998A is designed to support multiple footprints of input/output capacitors and inductors to accommodate a variety of applications. The LTC3892 features an adjustable gate drive voltage. The DC1998A is preset to provide a 10V gate drive voltage (DRVCC) for the switching MOSFETs and has 7.5V/6.7V rising/falling undervoltage lockout (UVLO) thresholds. In addition, the LTC3892 features a continuously adjustable gate drive voltage (5V to 10V) and selectable UVLO thresholds that allow the use and optimization of both logic-level and standard threshold MOSFETs. See the LTC3892 data sheet for a more complete description of its functionality and applications. The LTC3892 data sheet must be read in conjunction with this demo board manual for demonstration circuit 1998A. Design files for this circuit board are available at http://www.linear.com/demo/DC1998A L, LT, LTC, LTM, Linear Technology, Burst Mode 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 Minimum Input Voltage VALUE 6V Maximum Input Voltage 60V Output Voltage VOUT1 Regulation VIN = 8V – 55V 5V ± 2% Output Voltage VOUT2 Regulation VIN = 16V – 55V 12V ± 2% Maximum Continuous Output Current VOUT1 8A Maximum Continuous Output Current VOUT2 5A Preset Operating Frequency R14 = 35.7k 200kHz External Clock Sync Frequency Range 75kHz to 850kHz Efficiency VIN = 16V, VOUT2 = 12V, IOUT = 3A See Figure 3 Efficiency Curves for Complete Operating Range 97% Typical Output Ripple VOUT VIN = 36V, VOUT2 = 12V, IOUT = 3A (20MHz BW) <35mVP-P Quiescent Current at Shut-Down VIN = 16V – 55V <5µA Input Current at No-Load VIN = 16V – 55V <1mA dc1998afb 1 DEMO MANUAL DC1998A Quick Start Procedure Demonstration circuit 1998A is easy to set up to evaluate the performance of the LTC3892. For proper measurement equipment configuration, set up the circuit according to the diagram in Figure 1. Before proceeding to test, insert shunts into JP2, JP3 (RUN1, 2) into OFF position, which connects the RUN pins to ground (GND), and thus shuts down the outputs. Set jumper JP1 (MODE) into FC (forced continuous mode) position. 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 the DC1998A set up according to the proper measurement and equipment in Figure 1, apply 20V at VIN. Measure VOUT; it should read 0V. If desired, one can measure the shutdown supply current at this point. The supply current will be approximately 5µA, or less, in shutdown. voltage should be regulating. Measure VOUT1, it should measure 5V ±2% (do not apply more than the rated maximum voltage of 60V to the board or the part may be damaged). Vary the VOUT1 load, which should not exceed 8A. Vary the input voltage from 6V to 55V. VOUT1 should measure 5V ±2%. 3.Turn on VOUT2 of the circuit by inserting the shunt in header JP3 (RUN2) into the ON position. The output voltage should be regulating. Measure VOUT2, it should measure 12V ±2% (do not apply more than the rated maximum voltage of 60V to the board or the part may be damaged). Vary the VOUT2 load, which should not exceed 5A. Vary the input voltage from 16V to 55V. VOUT2 should measure 12V ±2%. 4.Set output current to zero and move jumper JP1 (MODE) into BURST MODE position and measure VOUT1 and VOUT2. 5.Set output current to zero and move jumper JP1 (MODE) into PLS SKIP position and measure VOUT1 and VOUT2. 2.Turn on VOUT1 of the circuit by inserting the shunt in header JP2 (RUN1) into the ON position. The output dc1998afb 2 DEMO MANUAL DC1998A Quick Start Procedure Figure 1. Proper Measurement Equipment Setup GND VIN Figure 2. Measuring Input or Output Ripple dc1998afb 3 DEMO MANUAL DC1998A Quick Start Procedure 98 96 94 96 94 PERCENT (%) PERCENT (%) 92 90 88 90 86 16V 24V 36V 48V 84 82 0.5 92 1.5 2.5 4.5 3.5 CURRENT (A) 5.5 6.5 16V 24V 36V 48V 88 7.5 86 0.5 1 1.5 2 2.5 3 3.5 CURRENT (A) 4.5 5 DC1998A F04 DC1998A F03 Figure 3. Efficiency vs Input Voltage, VOUT1, Burst Mode Operation 4 Figure 4. Efficiency vs Input Voltage, VOUT2, Burst Mode Operation DC1998A F05 Figure 5. Thermal Map, VIN 60V, IOUT1 5V at 8A, IOUT2 12V at 5A No Air Flow dc1998afb 4 DEMO MANUAL DC1998A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP, ALUM, 47µF, 63V, 20%, 10 X 10.5 SUN ELECT, 63HVH47M Required Circuit Components 1 1 CIN1 2 7 C2, C3, C4, C19, C20, C36, C37 CAP, 2.2µF, X7R, 100V, 10%, 1210 AVX, 12101C225KAT2A 3 1 C5 CAP, 0.1µF, X7R, 100V, 10%, 0805 AVX, 08051C104KAT2A 4 1 C6 CAP, 4.7µF, X5R, 50V, 10%, 0805 MURATA, GRM21BR61E475KA12L 5 3 C8, C21, C22 CAP, 0.1µF, X7R, 100V, 10%, 0603 MURATA, GRM188R72A104KA35D 6 1 C9 CAP, 1µF, X5R, 35V, 10%, 0603 TAIYO YUDEN, GMK107BJ105KA-T 7 1 C10 CAP, 27pF, NP0, 25V, 5%, 0603 AVX, 06033A270JAT2A 8 2 C11, C12 CAP, 1800pF, C0G, 50V, 5%, 0603 MURATA, GRM1885C1H182JA01D 9 2 C17, C18 CAP, 1000pF, NP0, 50V, 10%, 0603 AVX, 06035A102KAT2A 10 2 C13, C14 CAP, 100pF, NP0, 100V, 10%, 0603 AVX, 06031A101KAT2A 11 2 C15, C16 CAP, 0.01µF, X7R, 100V, 10%, 0603 AVX, 06031C103KAT2A 12 2 C24, C27 CAP, 10µF, X5R, 35V, 10%, 1206 TAIYO YUDEN, GMK316BJ106KL-T 13 1 C31 CAP, POSCAP, 150µF, 16V, 7343 PANASONIC, 16TQC150MYF 14 1 C32 CAP, POSCAP, 470µF, 6.3V 7343 PANASONIC, 6TPE470MI 15 1 L1 IND, PWR, 5.6µH, 20%, XAL1010 SERIES COILCRAFT, XAL1010-562MED 16 1 L2 IND, PWR, 15µH, 20%, XAL1010 SERIES COILCRAFT, XAL1010-153MED 17 2 Q1, Q2 XSTR, MOSFET, N-CH, 80V, 100A, TDSON-8 INFINEON, BSC057N08NS3 G 18 2 Q3, Q5 XSTR, MOSFET, N-CH, 75V, 100A, TDSON-8 INFINEON, BSC036NE7NS3 G 19 1 RS1 RES, SENSE, 0.005Ω 1% 1/4W,1206 VISHAY, WSL12065L000FEA 20 1 RS2 RES, SENSE, 0.008Ω 1% 1/4W,1206 VISHAY, WSL12068L000FEA 21 2 R8, R24 RES, 100k, 1%, 1/10W, 0603 VISHAY, CRCW0603100KFKEA 22 2 R9, R15 RES, 1M, 1%, 1/10W, 0603 VISHAY, CRCW06031M00FKEA 23 1 R14 RES, 35.7k, 1%, 1/10W, 0603 VISHAY, CRCW060335K7FKEA 24 1 R21 RES, 20k, 1/10W, 1%, 0603 VISHAY, CRCW060320K0FKEA 25 1 R22 RES, 10k, 1/10W, 1%, 0603 VISHAY, CRCW060310K0FKEA 26 1 R25 RES, 7.15k, 1/10W, 1%, 0603 VISHAY, CRCW06037K15FKEA 27 1 U1 IC, LTC3892EUH#PBF, QFN32UH-5X5 LINEAR TECHNOLOGY, LTC3892EUH#PBF dc1998afb 5 DEMO MANUAL DC1998A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Additional Demo Board Circuit Components 1 0 CIN2 CAP, OPTION, 10 X 10.5 OPT 2 0 C1, C7, C29, C30 CAP, OPTION, 0603 OPT 3 0 C23, C28, C34, C35 CAP, OPTION, 1206 OPT 4 0 C25 CAP, OPT, OSCON-SVP-F8 OPT 5 0 C26 CAP, OPT, OSCON-SVP-C6 OPT 6 0 C33 CAP, OPTION, 0805 OPT 7 0 D1, D2 DIODE, OPT, DI-123 OPT 8 0 L3 IND, OPT OPT 9 0 Q4, Q6 XSTR, OPT, WPACKV OPT 10 1 R1 RES, 0Ω, JUMPER 1/18W, 0805 VISHAY, CRCW08050000Z0EA 11 16 R2, R3, R5, R6, R16, R18, R19, R23, R29, R30, R32, R33, R34, R35, R40, R41 RES, 0Ω, JUMPER 1/18W, 0603 VISHAY, CRCW06030000Z0EA 12 0 R4, R7, R10, R11, R12, R13, R17, R20, R26, R27, R28, R31, R38, R39 RES, OPTION, 0603 OPT 13 0 R36, R37 RES, OPTION, 0805 OPT 14 0 TP1, TP2 TEST PAD SMD OPT Hardware/Components (For Demo Board Only) 1 12 E1 TO E12 TESTPOINT, TURRET, 0.094" MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 JP1 CONN, HEADER, 2 x 3, 2mm SULLINS, NRPN032PAEN-RC 3 2 JP2, JP3 CONN, HEADER, 1 x 3, 2mm SULLINS, NRPN031PAEN-RC 4 3 XJP1, XJP2, XJP3 SHUNT, 2mm SAMTEC, 2SN-BK-G 5 4 MTGS AT 4 CORNERS STANDOFF, NYLON, SNAP-ON, 0.500" TALL KEYSTONE, 8833 dc1998afb 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 E7 E9 7343 TP2 E12 E11 C10 C34 OPT C35 OPT C25 OPT OPT L3 C16 .01uF R24 100k 27pF 5 1. ALL RESISTORS AND CAPACITORS ARE 0603. C36 2.2uF 100V 1210 R21 INTVCC 15uH L2 OPT OFF ON Q1 JP2 3 2 1 RUN1 4 R40 0 VIN 4 OPT R38 R36 OPT 0805 RUN1 VIN Q4 OPT 4 4 0 R32 0 C6 DRVCC C5 0.1uF 100V 0805 C29 OPT C21 JP3 1 3 2 1 RUN2 0.1uF OFF ON C17 1nF 19 17 16 10 9 6 15 12 11 21 4 3 20 22 2 R41 0 VIN D1 OPT 0 R34 18 RUN1 EXTVCC 4.7uF 0805 R29 C19 VIN 2.2uF 1210 100V C13 100pF 1 Meg R15 1 Meg R9 BSC057N08NS3 G 20K C12 1800pF R1 0 0805 + CIN1 + CIN2 47uF/63V OPT 63HVH47M 63HVH47M INTVCC C37 2.2uF 100V 1210 C24 10uF 35V Q3 1206 BSC036NE7NS3 G 0.008 1206 RS2 C33 VIN C23 OPT 1206 R25 7.15k R17 OPT VOUT1 C4 2.2uF 100V 1210 C9 1uF NOTE: UNLESS OTHERWISE SPECIFIED GND GND GND + + OPT R28 OPT VOUT2 Vin_EMI TP1 GND 0 R23 C3 2.2uF 100V 1210 R16 0 VOUT2 C2 2.2uF 100V 1210 R26 E6 E5 E4 E3 E1 C31 150uF 16V 12V / 5A VOUT2 VOUT1 VOUT2 EXTVCC PGOOD2 PGOOD1 GND 6V UP TO 60V VIN 4 5 VIN 5 3 2 1 3 OPT R39 RUN2 R37 OPT 0805 VIN DRVCC BOOST2 BG2 SW2 TG2 SENSE2+ SENSE2- RUN1 TRACK/SS2 ITH2 VFB2 EXTVCC PGOOD2 PGOOD1 DRVCC VIN FREQ DRVUV DRVSET ILIM VPRG1 C30 OPT DRVCC BOOST1 BG1 SW1 TG1 SENSE1+ SENSE1- RUN2 TRACK/SS1 ITH1 VFB1 INTVCC PLLIN/MODE U1 LTC3892EUH 3 GND 33 1 4 4 Q5 BSC036NE7NS3 G 0.1uF C22 0 2 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE VICTOR K. LT L1 1 3 5 C27 10uF 35V 1206 0.005 1206 RS1 BURST 2 4 6 C26 OPT + + E10 DATE: N/A SIZE LTC3892EUH 1 DEMO CIRCUIT 1998A Monday, May 18, 2015 IC NO. SHEET 1 2 OF 1 REV. LOW IQ DUAL OUTPUT HIGH VOLTAGE STEP-DOWN CONVERTER LTC Confidential-For Customer Use Only 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com GND 5V / 8A C32 470uF 6.3V 7343 VOUT1 VOUT2 E8 DATE 5-18-15 SYNC VOUT1 VOUT1 OPT R27 C15 R31 .01uF OPT 10K C11 1800pF 0 0 R22 R19 R18 TECHNOLOGY Fax: (408)434-0507 C28 OPT 1206 C14 100pF INTVCC C7 OPT 100K R8 INTVCC R20 OPT JP1 MODE 0 E2 VICTOR K. R2 APPROVED PRODUCTION 2 1 DESCRIPTION REVISION HISTORY REV TITLE: SCHEMATIC Q6 OPT APPROVALS 4 FC C1 OPT __ ECO PLS SKIP 5.6uH R14 35.7K R7 OPT INTVCC BSC057N08NS3 G Q2 C20 2.2uF 100V 1210 R13 OPT R12 OPT VIN 0 R33 R30 0.1uF CUSTOMER NOTICE D2 OPT 0 R35 R11 OPT C8 C18 1nF INTVCC RUN2 ILIM R10 OPT R4 OPT R6 0 R5 0 2 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 APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 2 24 23 25 26 31 32 7 27 29 30 5 2 1 13 14 8 28 R3 0 5 1 2 3 5 1 2 3 3 2 1 5 3 2 1 5 1 2 3 5 A B C D DEMO MANUAL DC1998A Schematic Diagram dc1998afb 7 DEMO MANUAL DC1998A 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 dc1998afb 8 Linear Technology Corporation LT 0516 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015