DEMO MANUAL DC1877A LTC3630AEDHC High Efficiency High Voltage 500mA Synchronous Step-Down Converter Description Demonstration circuit 1877A is a 500mA output DC/DC power supply featuring LTC®3630A (DFN package), with 4V to 76V input range. The LTC3630A operates in a high efficiency Burst Mode® operation and includes internal high and low side switches. The board provides jumper selected output voltages of 1.8V, 3.3V, 5V and an option for additional voltages. LTC3630A has internal soft-start and a provision for increasing soft-start time. Included on the board is an ON/OFF jumper that can also be configured as a precision undervoltage lockout. Additional pc pads are included for programming current limit to optimize efficiency and for reducing output voltage ripple and reducing component size. A terminal (FBO) is available to allow multiple boards to be paralleled for increasing output current. Output voltage between 800mV and VIN can be programmed using optional resistors. (Higher voltage output capacitors may be required.) The LTC3630A data sheet gives a complete description of the operation and application information. The data sheet must be read in conjunction with this demo manual. Design files for this circuit board are available at http://www.linear.com/demo/DC1877A 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. Performance Summary Table 1. Specifications are at TA = 25°C PARAMETER CONDITION VALUE Input Voltage Range (1.8V, 3.3V Outputs) 4V to 76V 1.8V Output VIN = 76V, IOUT = 500mA 1.8V ±2% 3.3V Output VIN = 76V, IOUT = 500mA 3.3V ±2% 5V Output VIN = 76V, IOUT = 500mA 5V ±2% Maximum Output Current VIN = 76V, VOUT = 5V 500mA Typical Output Voltage Ripple VIN = 76V, VOUT = 5V 84mVP-P Typical Efficiency (See Figure 3) dc1877af 1 DEMO MANUAL DC1877A Quick Start Procedure This demonstration circuit 1877A can be evaluated using the setup shown in Figure 1. 1.Connect the DVMs to the input and output. Select 5V setting using jumper JP1 (B position) and JP2 (A position), select ON position for JP3. 2.With input power supply set for 0V, connect the supply to VIN and GND terminals using short (less than 10 inches) leads, preferably twisted leads. Connect a suitable load to VOUT and GND terminals. 3.Slowly increase the input power supply to 10V. Observe output voltage and verify that it meets the specifications in Table 1. Measure output voltage with and without the load. 4.Move jumpers JP1 and JP2 to the other two fixed voltage settings and verify that each output voltage meets the values as shown in Table 1. 5.Once the proper output voltages are established, adjust the load and input voltage within the operating range and observe the output voltage regulation, ripple voltage and other parameters. Notes: 1. IMPORTANT: 60V or higher voltage can result in an electric shock if care is not taken. Also, hot plugging the circuit to a power supply that has more than 40V present at its output can produce a high voltage transient exceeding the absolute maximum input voltage which can damage the LTC3630A. 2. 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. Load Figure 1. Proper Measurement Equipment Setup dc1877af 2 DEMO MANUAL DC1877A Quick Start Procedure Circuit Options RUN Pin Components: The converter is enabled when the RUN pin voltage exceeds 1.21V and is disabled when dropping below 1.1V. Pulling the RUN pin below 700mV forces a low quiescent current shutdown. Moving JP3 to the ON position allows an internal current to pull the RUN pin up to 5V. R1 and R2 are used to program input undervoltage lockout. Select suitable resistors to divide the input voltage down to the precision threshold voltage levels that enable and disable the converter. Note that the maximum voltage on the RUN pin is 6V, therefore a nominal 5V zener diode (D1) is required to limit the RUN pin voltage when high input voltages are used. 12VIN 36VIN 76VIN 0.01 0.1 LOAD CURRENT (A) 1 DC1788a F03a EFFICIENCY (%) ISET Components: C3, R3 and R4 are used to provide a number of features and circuit enhancements such as, output current limit, input current limit, optimizing output ripple voltage reduction and efficiency improvement. R4 sets maximum output current, see Figure 2 in LTC3630A data sheet, leave open for maximum load current. R3 and R4 can be used to set input current limit. C3 is used to reduce output voltage ripple and optimize efficiency. See data sheet for details. 100 3.3VOUT 95 90 85 80 75 70 65 60 55 50 45 40 35 30 0.001 12VIN 36VIN 76VIN 0.01 0.1 LOAD CURRENT (A) 1 DC1788a F03b EFFICIENCY (%) Optional Output Voltage: Additional output voltages can be programmed by selecting proper resistors for the R6 and R7 feedback network. C5 is a feedforward capacitor to optimize transient response and increase stability. Both JP1 and JP2 must be in A position if R6 and R7 are used. The 10V rated output capacitors should be replaced with suitable voltage ratings. EFFICIENCY (%) Detailed information is contained in the data sheet. 100 1.8VOUT 95 90 85 80 75 70 65 60 55 50 45 40 35 30 0.001 100 5VOUT 95 90 85 80 75 70 65 60 55 50 45 40 35 30 0.001 12VIN 36VIN 76VIN 0.01 0.1 LOAD CURRENT (A) 1 DC1788a F03c Figure 3. Efficiency Curves Figure 2. Measuring Input or Output Voltage Ripple dc1877af 3 DEMO MANUAL DC1877A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 CAP, 0.22µF, X7R, 100V, 10%, 0805 MURATA, GRM21AR72A224KAC5L 2 1 C2 CAP, 4.7µF, X7R, 100V, 20%, 2220 TDK, C5750X7R2A475M230KA 3 1 C3 CAP, 220pF, X7R, 50V, 10%, 0603 AVX, 06035C221KAT2A 4 1 C4 CAP, 0.047µF, X7R, 25V, 10%, 0603 AVX, 06033C473KAT2A 5 2 C6, C7 CAP, 100µF, X5R, 10V, 20%, 1210 MURATA, GRM32ER61A107ME20L 6 1 C9 CAP, 0.1µF, X7R, 25V, 10%, 0603 AVX, 06033C104KAT2A 7 1 L1 IND, POWER, 68µH, 1.6A, 30%, SMD SUMIDA, CDRH105RNP-680NC 8 1 R4 RES, 220k, 1/10W, 5%, 0603 VISHAY, CRCW0603220KJNEA 9 1 R5 RES, 4.7Ω, 1/8W, 5%, 0805 VISHAY, CRCW08054R70JNEA 10 2 R6 RES, 0Ω, 1/10W, 0603 VISHAY, CRCW06030000Z0EA 11 1 U1 IC, LTC3630AEDHC, DFN 5mm x 3mm LINEAR TECHNOLOGY, LTC3630AEDHC#PBF Additional Demo Board Circuit Components 1 0 C5 CAP, OPTION, 0603 2 0 C8, C10, C11 CAP, OPTION, 1210 3 0 D1 DIODE, OPTION 4 0 R1, R2, R3, R7 RES, OPTION, 0603 Hardware: For Demo Board Only 1 6 E1, E2, E3, E4, E5, E6 TEST POINT, TURRET, 0.094" MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07-0 2 3 JP1, JP2, JP3 CONN, HEADER, 1 x 3, 2mm SAMTEC, TMM-103-02-L-S 3 3 JP1, JP2, JP3 SHUNT, 2mm SAMTEC, 2SN-BK-G 4 1 PCB, DC1877A DEMO CIRCUIT 1877A 5 2 STENCIL, DC1877A (TOP AND BOTTOM) STENCIL DC1877A dc1877af 4 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 E5 E4 R5 4.7 0805 VIN OPT D1 C1 220nF 100V 0805 R3 OFF R2 OPT ON OPT R1 OPT 2 JP3 R4 220k 3 1 2 B A A B A 3.3V 5.0V EXT. R 5 3. FOR 5V OUTPUT, VIN RANGE IS 6V-76V. A B B 1.8V JP2 JP1 VOUT VIN 11 12 5 3 NC NC NC NC ISET FBO RUN VIN SS VPRG2 VPRG1 VFB SW CUSTOMER NOTICE 2 C3 4 220pF 13 15 C2 4.7uF 100V 2220 U1 LTC3630AEDHC 10 6 7 9 1 3 4 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. L1 2 B A 2 B A 1 1 2 JP2 2 JP1 R7 OPT ECO C5 OPT 1 SCALE = NONE DESCRIPTION C10 OPT 1210 VOUT C6 100uF 10V 1210 C8 OPT 1210 E2 DATE 7-9-13 E6 E3 GND GND VOUT C9 1.8V/3.3V/5V 0.1uF 500mA Charlie Z. APPROVED 1 DATE: 2 Friday, December 12, 2014 1 SHEET 1 OF 1 HIGH EFFICIENCY, 76V, 500mA SYNCHRONOUS STEP-DOWN CONVERTER IC NO. REV. SIZE LTC3630AEDHC 1 N/A DEMO CIRCUIT 1877A 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only C11 OPT 1210 C7 100uF 10V 1210 PRODUCTION REVISION HISTORY TECHNOLOGY REV 2 Charlie Z. TITLE: SCHEMATIC HZ APPROVALS C4 47nF 3 3 R6 0 VOUT 68uH SUMIDA CDRH105 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. 1. ALL RESISTORS AND CAPACITORS ARE 0603. NOTE: UNLESS OTHERWISE SPECIFIED FBO GND VIN 4V - 76V E1 4 GND 8 GND 16 GND 14 GND 17 D 5 A B C D DEMO MANUAL DC1877A Schematic Diagram dc1877af 5 DEMO MANUAL DC1877A 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 dc1877af 6 Linear Technology Corporation LT 0115 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015