DEMO MANUAL DC1667A LTC3600 16V, 1.5A Synchronous Step-Down Regulator with Programmable Reference DESCRIPTION Demonstration circuit DC1667A is a step-down DC/ DC converter using LTC®3600 monolithic synchronous buck regulator. DC1667A has an input voltage range of 4.5V to 15V, and is capable of delivering up to 1.5A of output current. The output voltage of the DC1667 can be set by a single resistor from 0V to (VIN – 0.5)V. At light load conditions, DC1667 can operate in discontinuous mode to improve the efficiency. During shutdown mode, LTC3600 consumes less than 1µA. The switching frequency of LTC3600 is programmable from 200kHz to 4MHz. DC1667A uses low profile surface mount components. PERFORMANCE SUMMARY PARAMETER These features and the availability of LTC3600 in a 12-lead DFN/MSOP package, make it ideal for use in point-of-load power supplies, battery-powered equipments and voltage tracking systems. The LTC3600 data sheet must be read in conjunction with this demo manual for working on or modifying the demo circuit DC1667A. Design files for this circuit board are available at http://www.linear.com/demo/DC1667A L, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. (TA = 25°C) CONDITIONS Input Voltage Range Default Output Voltage VOUT VALUE 4.5V to 15V VIN = 4.5V to 15V, IOUT = 0A to 1.5A, JP10: CCM 1.215V ± 2% (1.19V to 1.24V) Maximum Continuous Output Current 1.5A Default Operating Frequency 1MHz Typical Output Voltage Ripple VIN = 5V, VOUT = 1.2V, IOUT = 1.5A, fSW = 1MHz <10mV (See Figure 4) Efficiency VIN = 5V, VOUT = 1.2V, IOUT = 1.5A, fSW = 1MHz 78% (See Figure 3) dc1667afa 1 DEMO MANUAL DC1667A QUICK START PROCEDURE Demonstration circuit DC1667A is easy to set up to evaluate the performance of the LTC3600. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1.Place jumpers in the following positions for a typical 1.2V output application: JP2 JP7 JP8 JP9 JP10 1.2V COMP PGOOD RUN MODE/SYNC 1.2V EXT DIS OFF CCM 2.With power off, connect the input power supply, load and meters as shown in Figure 1. Preset the load to 0A and VIN supply to 5V. 3.Turn on the power supply at the input. Measure and make sure the input voltage is 5V. Turn on the circuit by inserting the shunt in header JP9 to the ON position. The output voltage should be 1.215V ± 2% (1.19V to 1.24V). 4.Once the proper output voltage is established, adjust the load within the operating range and observe the output voltage regulation, output voltage ripple, efficiency and other parameters. Refer to Figure 2 for proper input/ output voltage ripple measurement. 5.To select other output voltages, LTC3600 has to be shut down by putting RUN pin jumper to the OFF position or turning off the input supply. After the IC is shut down, move the shunt to other output voltage selections, such as 1.8V or 3.3V, and repeat tests 1 through 4. The output voltage tolerance should remain at VOUT ± 2%. LOAD (0A TO 1.5A) VIN 4.5V TO 15V + + – – – – + VOUT + + – DC1667A F01 Figure 1. Proper Equipment Measurement Setup INPUT OR OUTPUT CAPACITOR Figure 2. Scope Probe Placements for Measuring Input or Output Ripple 2 dc1667afa DEMO MANUAL DC1667A QUICK START PROCEDURE 100 90 EFFICIENCY (%) 80 70 60 50 40 30 5VIN , 1.2VOUT DCM 12VIN , 1.2VOUT DCM 5VIN , 1.2VOUT CCM 12VIN , 1.2VOUT CCM 20 10 0 0.01 0.1 LOAD CURRENT (A) 1 DC1667A F03 Figure 3. Measured Efficiency (VOUT = 1.2V) 20MHz BW LIMIT VOUT 10mV/DIV SWITCHING NODE 5V/DIV 1µs/DIV DC1667A F04 Figure 4. Measured Output Voltage Ripple at 5V Input, 1.2V Output, 1.5A with Standard Demo Circuit Default Setup dc1667afa 3 DEMO MANUAL DC1667A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CIN2 Capacitor, X5R 22µF 16V 20% 1210 TDK C3225X5R1C226M 2 1 COUT1 Capacitor, X5R 47µF 6.3V 20% 1210 Taiyo Yuden JMK325BJ476MM-T 3 1 C3 Capacitor, X5R 4.7µF 16V 20% 0805 Taiyo Yuden EMK212BJ475MG 4 1 C4 Capacitor, X7R 0.1µF 25V 10% 0603 AVX 06033C104KAT2A 5 1 L1 Inductor, 2.2µH IHLP-2020CZ-01 Vishay IHLP-2020CZ-ER 2R2M01 6 1 R2 Resistor, Chip 24.3K 0.06W 1% 0603 Vishay CRCW060324K3FKEA 7 1 R9 Resistor, Chip 36.5K 0.06W 1% 0402 Vishay CRCW040236K5FKED 8 1 U1 I.C., Voltage Regulator DFN(12)(DD) 3mm × 3mm Linear Technology Corporation LTC3600EDD Additional Demo Board Circuit Components 1 1 CIN1 Capacitor, Tantalum 3.3µF 35V 20% 6032 AVX TAJW335M035R 2 1 CIN3 Capacitor, X5R 22µF 16V 20% 1210 TDK C3225X5R1C226M 3 2 COUT2, COUT3 Capacitor, 1210 4 1 C1 Capacitor, NPO 68pF 50V 10% 0603 5 1 C2 Capacitor, 0402 6 1 C5 Capacitor, X7R 0.01µF 16V 20% 0402 7 1 C6 Capacitor, 0805 8 1 RSD Resistor, Chip 1M 0.06W 5% 0603 Vishay CRCW06031M00JNEA 9 1 R1 Resistor, Chip 16.2k 0.06W 1% 0603 Vishay CRCW060316K2FKEA 10 1 R3 Resistor, Chip 35K7 0.06W 1% 0603 Vishay CRCW060335K7FKEA 11 1 R4 Resistor, Chip 66.5k 0.06W 1% 0603 Vishay CRCW060366K5FKEA 12 1 R5 Resistor, 0603 13 1 R6 Resistor, Chip 56k 0.06W 5% 0603 Vishay CRCW060356K0JKEA 14 1 R7 Resistor, Chip 100k 0.06W 5% 0603 Vishay CRCW0603100KJNEA 15 1 R8 Resistor, 0402 16 2 R10, R11 Resistor, 0603 17 1 R12 Resistor/Jumper, Chip 0Ω 1/8W 1A 0805 Vishay CRCW08050000ZOEA AVX 06035A680KAT1A AVX 0402YC103MAT2A Hardware-For Demo Board Only 1 7 E1-E7 Turret, Testpoint .062 Thick Board Mill Max 2501-2-00-80-00-00-07-0 2 4 JP1–JP3, JP5 Jumper, 2 Pins 2mm Ctrs. Samtec TMM-102-02-L-S 3 1 JP6 4 3 JP7–JP9 Headers, Single Row 3 Pins 2mm Ctrs. Samtec TMM-103-02-L-S 5 1 JP10 Headers, Double Row 2mm × 3 2mm Ctrs. Samtec TMM-103-02-L-D 6 5 XJP2, XJP7–XJP10 Shunt, 2mm Ctrs. Samtec 2SN-BK-G 7 1 Stencil Stencil DC1667A 4 Samtec TMM-102-02-L-S dc1667afa 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 INTVCC INTVCC VIN INTVCC VOUT INTVCC B A 1. ALL RESISTORS 0402. 2. ALL CAPACITORS 0402. B NOTE: UNLESS OTHERWISE SPECIFIED. A REV D JEFF Z. SCALE = NONE PCB DES. APP ENG. D DATE DATE: E IC NO. SHEET 1 OF 1 4 REV. SIZE APPROVED E TECHNOLOGY TITLE: SCHEMATIC APPROVALS VOUT + VIN INTVCC DESCRIPTION REVISION HISTORY THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. C ECO INTVCC CUSTOMER NOTICE 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. C 1 2 3 4 DEMO MANUAL DC1667A SCHEMATIC DIAGRAM dc1667afa 5 DEMO MANUAL DC1667A 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 6 dc1667afa Linear Technology Corporation LT 1214 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2011