DEMO MANUAL DC1821B LTC3114EDHC-1 40V, 1A Synchronous Buck-Boost DC/DC Converter with Output Current Limit DESCRIPTION Demonstration circuit 1821B features the LTC®3114-1, a wide operating range synchronous monolithic buck-boost converter with programmable average output current. In PWM mode, the LTC3114-1 operates at 1.2MHz to optimize small size with high efficiency operation. The DC1821B demo board has two user selectable operating modes: Burst Mode® operation and Fixed Frequency PWM (JP2). There is also an accurate programmable RUN pin which is used to ENABLE the converter (JP1). The demo board also incorporates diode D1 to backfeed VCC to improve efficiency in some applications. If the demo board output voltage is changed to a higher voltage, D1 should be removed. Consult the data sheet for more information. The LTC3114-1 uses average current mode control to simplify voltage loop compensation and provide good line and load transient response. Figure 1 shows typical demo board efficiency. Figure 2 shows the response to an input voltage step while Figure 3 shows the load step response. The DC1821B operates with a 2.7V to 40V input voltage range. The demo board has been designed with the output voltage set to 5V. The LTC3114-1 incorporates a proprietary low noise switching algorithm which optimizes efficiency with input voltages above, below or equal to the output voltage and ensures seamless transitions between operating modes. The LTC3114-1 data sheet has detailed information about the operation, specifications, and applications of the part. The data sheet should be read in conjunction with this Quick Start Guide. PERFORMANCE SUMMARY Design files for this circuit board are available at http://www.linear.com/demo/DC1821B L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C PARAMETER TYP Input Voltage Range 2.7V to 40V 5V VOUT IOUT (See Note 1) 1A for VIN > 6V Efficiency See Figure 1 NOTE 1: The demo board output current is a function of VIN. Please refer to the data sheet for more information. dc1821bf 1 DEMO MANUAL DC1821B DESCRIPTION DC1821B Typical Efficiency in Auto Burst Mode Operation 100 EFFICIENCY (%) 90 80 70 250mA LOAD 500mA LOAD 750mA LOAD 1A LOAD 60 50 0 5 10 15 20 25 VIN (V) 30 35 40 dc1821a F01 Figure 1. DC1821B Efficiency in Auto Burst Mode Operation VOUT: 500mV/DIV VIN: 5V/DIV dc1821a F02 Figure 2. DC1821B Input Voltage Step Response. VIN Stepped from 3.3V to 12V IOUT is 500mA VOUT: 100mV/DIV IOUT: 500mA/DIV dc1821a F03 Figure 3. DC1821B Step Load Response. VIN = 12V Load Step is from 250mA to 750mA 2 dc1821bf DEMO MANUAL DC1821B QUICK START PROCEDURE Using short twisted pair leads for any power connections and with all loads and power supplies off, refer to Figure 4 for the proper measurement and equipment setup. The battery/power supply (PS1) should not be connected to the circuit until told to do so in the procedure below. 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 5), or by using an oscilloscope probe tip jack. 1. Jumper and PS1 settings to start: PS1: OFF JP1: RUN ON JP2: MODE FIXED FREQUENCY 2. With power OFF connect the power supply (PS1) as shown in Figure 4. If accurate current measurements are desired (for efficiency calculations for example) connect an ammeter in series with the supply as shown. The ammeter is not required however. 3. Connect a 500mA load to VOUT as shown in Figure 4 (10Ω for VOUT = 5V). Connect an ammeter if accurate current measurement or monitoring is desired. 4. Turn on PS1 and slowly increase voltage until the voltage at VIN is 4V. 5. Verify VOUT is ~5V. 6. VIN can now be varied between 2.7V and 40V. IOUT may need to be reduced for VIN < 4V. 7. Load current (IOUT) can also be varied. The maximum IOUT is a function of VIN and the current limit. Consult the data sheet for more information on IOUT vs VIN. In general for VIN > 5V IOUT can be increased to 1A. 8. For operation in Burst Mode operation move Jumper JP2 to BURST. See the data sheet for more information. 9. NOTE: If VOUT drops out of regulation, check to be sure the maximum load has not been exceeded, or that VIN is not below the minimum value for regulation (see data sheet) 10. NOTE: If VOUT is changed to a voltage higher than 5V, D1 should be removed or the LTC3114-1 could be damaged. GND VIN Figure 4. Proper Measurement Equipment Setup Figure 5. Measuring Input or Output Ripple dc1821bf 3 DEMO MANUAL DC1821B PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 C1, C2 CAP CER 0.068μF 16V 10% X7R 0402 TDK, C1005X7R1C683K 2 1 C3 CAP CER 4.7μF 6.3V X5R 20% 0603 TDK, C1608X5R0J475M 3 2 C4, C13 CAP CER 22μF 25V X7R 20% 1812 TDK, C4532X7R1E226M 4 1 C5 CAP CER 1.0μF 25V X5R 0603 TDK, C1608X5R1E105M 5 1 C6 CAP CER 10μF 50V 20% X7R 2220 TDK, C5750X7R1H106M230KB 6 1 C8 CAP CER 1.0μF 50V X7R 20% 1206 TDK, C3216X7R1H105M 7 1 C9 CAP CER 4700pF 25V X7R 10% 0402 TDK, C1005X7R1E472K 8 1 C10 CAP CER 10pF 50V C0G 0402 TDK, C1005C0G1H100D 9 1 C11 CAP CER 0.047μF 25V 20% X7R 0402 TDK, C1005X7R1E473M050BC 10 1 D1 DIODE SCHOTTKY 20V NXP, PMEG2010AEH 11 1 D2 DIODE SCHOTTKY 60V, 2A NXP, PMEG6020ER,115 12 1 L1 INDUCTOR, 6.8μH ±30% COILCRAFT, MSS1048-682NLB 13 1 R1 RES 2.00M 1/16W 1% 0402 SMD VISHAY, CRCW04022M00FKED 14 1 R2 RES 499k 1/16W 1% 0402 SMD VISHAY, CRCW0402499KFKED 15 1 R3 RES SMD 10k 1% 1/16W 0402 VISHAY,CRCW040210K0FKED 16 1 R4 RES 27.4k 1/16W 1% 0402 SMD VISHAY, CRCW040227K4FKED 17 1 R5 RES 1.00M 1/16W 1% 0402 SMD VISHAY, CRCW04021M00FKED 18 1 R8 RES 49.9Ω 1/16W 1% 0402 SMD VISHAY, CRCW040249R9FKED 19 1 U1 40V, 1A BUCK-BOOST DC/DC CONVERTER WITH PROGRAMMABLE OUTPUT CURRENT LINEAR TECHNOLOGY, LTC3114MDHC-1 Additional Demo Board Circuit Components 20 0 C7 CAP 330μF 63V ELECT MVA SMD UNITED CHEMI-CON EMVA630ADA331MKG5S 21 0 C12 CAP CER 1000pF 25V X7R 0402 TDK, C1005X7R1E102M 22 0 C14 DNP 23 0 R6, R7 DNP Hardware for Demo Board Only 24 4 E1, E2, E3, E4 TURRET, 0.09" DIA MILL-MAX, 2501-2-00-80-00-00-07-0 25 2 JP2, JP1 HEADERS, 3 PINS, 2mm CTRs SULLINS, NRPN031PAEN-RC 26 2 XJP1, XJP2 SHUNT, 2mm CTRs SAMTEC, 2SN-BK-G 27 4 STAND OFF STAND-OFF, NYLON 0.50" TALL KEYSTONE, 8832 (SNAP ON) 4 dc1821bf 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 VIN OFF ON E2 JP1 RUN GND 1 2 3 C6 10uF 50V 2.7V - 40V E1 5 DNP R6 + R5 1M C7 OPT VIN PROG MODE RUN BURST MODE FIXED FREQ R3 10k 5 16 4 PVIN VIN BST1 CUSTOMER NOTICE RUN VIN C11 47nF MODE RUN 14 10 13 JP2 MODE 1 2 3 VC FB LDO PLDO PVOUT BST2 LTC3114-1 6.8uH L1 4 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 3 MODE LDO GND R4 27.4k C9 4700pF C2 68nF 3 SCALE = NONE J.NOON NC APPROVALS U1 6 7 9 11 3 12 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. C12 DNP C8 1uF 50V C1 68nF D2 PMEG6020ER 4 15 SW1 GND 8 GND 17 2 SW2 PGND 1 D 5 C10 10pF R2 499k 1% R1 2M 1% R8 49.9 1% DESCRIPTION DNP C14 DNP R7 C4 22uF 25V VOUT C13 22uF 25V J.NOON VOUT 6-6-16 DATE E4 GND 5.0V / 1A C5 1uF 25V E3 APPROVED 1 DATE: N/A SIZE 11 - 7 - 15 IC NO. 2 LTC3114-1EDHC DEMO CIRCUIT 1821B 1 SHEET 1 OF 1 1 40V, 1A SYNCHRONOUS BUCK - BOOST DC / DC CONVERTER WITH PROGRAMMABLE OUTPUT CURRENT REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only PRODUCTION REVISION HISTORY TECHNOLOGY LDO REV TITLE: SCHEMATIC C3 4.7uF 6.3V D1 PMEG2010AEH - ECO 2 A B C D DEMO MANUAL DC1821B SCHEMATIC DIAGRAM dc1821bf 5 DEMO MANUAL DC1821B 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 dc1821bf Linear Technology Corporation LT 0716• PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2016