DEMO MANUAL DC2045A LTC3118EUFD 18V, 2A Buck-Boost DC/DC Converter with Low-Loss Dual Power Path Description Demonstration Circuit 2045A featuring the LTC3118 is a dual input fixed frequency synchronous buck-boost converter with an intelligent integrated low-loss Power-Path™. The unique all N-Channel architecture provides efficient operation from either input source to a programmable output voltage above, below or equal to the input. Voltage capability of up to 18V provides flexibility and voltage margin for a variety of applications and power sources. The LTC3118 uses a low noise, current mode architecture with a fixed 1.2MHz PWM mode frequency that minimizes the solution footprint. For high efficiency at light loads, automatic Burst Mode™ operation can be selected consuming only 50μA of quiescent current in sleep. Typical efficiencies for both Burst Mode and fixed frequency are shown in Figure 1. JP2 in the FIXED FREQ position results in low output ripple but also lower efficiency at light loads. Moving the JP2 position to AUTOBURST enables Burst Mode operation which improves efficiency at light load. System level features include selectable IDEAL DIODE Mode (shown in Figure 2) or PRIORITY mode operation (shown in Figure 3) The system can be monitored through V1GD, V2GD and PGD (power good) indicators There are accurate RUN comparators to program independent UVLO thresholds, and output disconnect in shutdown. Other features include 2μA shutdown current, short-circuit protection, soft-start, inductor current limit and thermal overload protection. The DC2045A circuit has excellent transient load response in both fixed frequency and automatic Burst Mode operation as shown in Figures 4 and 5. The LTC3118 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. Design files for this circuit board are available at http://www.linear.com/demo/DC2045A L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Performance Summary Specifications are at TA = 25°C Input Voltage Range: 2.5V to 18.0V VOUT 5.0V IOUT 2.0A for VIN > 5.0V dc2045af 1 DEMO MANUAL DC2045A Quick Start Procedure 100 90 80 EFFICIENCY (%) 70 60 50 VIN=3.3V, BURST MODE 40 VIN=5V, BURST MODE 30 VIN=12V, BURST MODE 20 VIN=3.3V, FIXED FREQ VIN=5V, FIXED FREQ 10 VIN=12V, FIXED FREQ 0 1 10 100 1000 10000 LOAD (mA) Figure 1. Typical Efficiency as a Function of Input Voltage and Load Current VOUT = 100mV/DIV VOUT DC = 5V VIN1 = 2V/DIV VIN1 PEAK = 10V VIN1 VALLEY = 4V VIN2 = 2V/DIV VIN2 DC = 8V Figure 2. Ideal Diode Mode Operation VIN1 = 2V/DIV VOLTAGE PEAK = 10V VOLTAGE VALLEY = 1V VOUT = 500mV/DIV VOUT DC = 5V IIN1 = 500mA/DIV VIN2 = 14V and is Not Shown on Screen Figure 3. Transitioning from VIN1 to VIN2 and Back in PRIORITY Mode Operation with VIN2 at 14V 2 dc2045af DEMO MANUAL DC2045A Quick Start Procedure OUTPUT VOLTAGE OUTPUT CURRENT Figure 4. 100mA to 600mA Load Transient with VIN1 = 3.5V in Fixed Frequency Mode OUTPUT VOLTAGE OUTPUT CURRENT Figure 5. 50mA to 600mA Load Transient with VIN1 = 3.5V in Burst Mode dc2045af 3 DEMO MANUAL DC2045A Quick Start Procedure Using short twisted pair leads for any power connections and with all loads and power supplies off, refer to Figure 6 for the proper measurement and equipment setup. The Power Supplies 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. The indicators for PGD, V1GD and V2GD are negative logic. PGD indicates the output voltage is good if it is pulled to ground and V1GD and V2GD indicate that the input voltage on the respective sources are good if the pins are pulled to ground. 1. JP1 and JP2 settings to start: JP1 SELECT = IDEAL DIODE (VCC) JP2 MODE = FIXED FREQ (VCC) 2. With power OFF connect the power supplies (PS1, PS2) as shown in Figure 6. If accurate current measurements are desired (for efficiency calculations for example) then connect the ammeters in series with the supplies as shown. The ammeters however, are not required. 3. Connect the load, set at 50Ω, to VOUT as shown in Figure 6. Again, connect an ammeter if accurate current measurement or monitoring is desired. 7. Turn off PS1 and repeat steps 3 to 6 with PS2. The part will turn on with PS2 at approximately 4.5V. Once on, PS2 can be varied between 3.8V and 18V. The voltage measurements of step 5 will change where V1GD will be at VCC and V2GD will be pulled low. Set the load to 50Ω. 8. Set PS2 to 7V and turn on PS1 slowly increasing the voltage from 0V to 8V. Note that PS1 starts to supply the power as the voltage of PS1 exceeds the voltage on PS2 by at least 400mV. 9. Now decrease the voltage on PS1 and observe that when the voltage on VIN1 falls below the voltage on PS2, PS1 stops supplying the power and PS2 takes over. See Figure 2 for typical performance for steps 8 and 9. 10. Turn off PS1 and PS2. Change the SELECT jumper (JP1) to VCC (the PRIORITY position). Turn on PS2 and adjust it to 14V. 11. By cycling the voltage on PS1 from 1V to 10V you can observe the transition of power from PS2 to PS1 and back as the voltage on VIN1 goes through its startup (approximately 2.9V) and shutdown (approximately 2.5V) thresholds. Typical response is shown in Figure 3. Turn off PS1 and PS2. Steps 12 and 13 are optional for looking at load step response if desired. 4. Turn on the Power Supply, PS1, and slowly increase the voltage. The converter will start at approximately 2.9V. 12. With JP2 in the FIXED FREQ position and PS1 at 3.5V switch the load from 100mA to 600mA and back. Note the output voltage response. (Figure 4). 5. Verify VOUT is ~5.0V, and that V2GD is pulled high by VCC and PGD and V1GD are pulled low. 13. With JP2 in AUTOBURST and PS1 at 12V switch the load from 50 mA to 600 mA and back. Note the output voltage ripple. (Figure 5). See the data sheet for more information. 6. PS1 can now be varied between 2.5V and 18.0V. VOUT will remain in regulation for load currents up to 2 amps with VIN greater than VOUT. As VIN1 falls below VOUT the input current may increase to the maximum average inductor current, depending on the load, which will then limit the load current and the output voltage. 4 Note: Remove D1 for VOUT > 5V to prevent damage to the converter. dc2045af DEMO MANUAL DC2045A Quick Start Procedure PGD AM2 10k PS2 AM3 VM2 VM3 LOAD AM1 10k PS1 VM1 V2GD V1GD Figure 6. Measurement Setup dc2045af 5 DEMO MANUAL DC2045A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., 22µF, X7R, 25V, 20%, 1812 TDK, C4532X7R1E226M250KC Required Circuit Components 1 2 C1, C4 2 3 C2, C5, C9 3 0 C3, C6 4 2 5 6 7 CAP., 1µF, X7R, 25V, 10%, 0603 TDK, C1608X7R1E105K080AB CAP., ALUM., RADIAL, 150µF, 50V, 20% PANASONIC, EEU-FM1H151 C7, C8 CAP., 47µF, X5R, 10V, 20%, 1812 TDK, C4532X5R1A476M280KA 1 C10 CAP., 1800pF, C0G, 50V, 5%, 0603 TDK, CGJ3E2C0G1H182J080AA 1 C11 CAP., 22PF, NPO, 25V, 10%, 0603 KEMET, C0603C220K3GACTU 2 C12, C13 CAP., CER 0.1µF, 25V, 10%, X7R, 0603 TDK, C1608X7R1E104K (OPT) 8 2 C14, C17 CAP., CER 0.047µF, 50V, 10%, X7R, 0603 TDK, C1608X7R1H473K080AA 9 2 C15, C16 CAP., 0.01µF, X7R, 25V, 10%, 0603 TDK, C1608X7R1E103K080AA TDK, C1608X5R0J475M080AB 10 1 C18 CAP., 4.7µF, X5R, 6.3V, 20%, 0603 11 0 C19, C20, C21 (OPT) CAP., OPTION, 0603 12 1 D1 DIODE, SCHOTTKY, 30V, 0.2A, SOD-523F FAIRCHILD SEMI., BAT54XV2 13 1 L1 INDUCTOR, PWR., SHIELED, 3.3µH. XAL 40xx Series COILCRAFT, XAL4030-332MEC 14 1 R1 RES., 402k, 1/16W, 1%, 0402 VISHAY, CRCW0402402KFKED 15 1 R2 RES., 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED 16 1 R3 RES., 40.2k, 1/16W, 1%, 0402 VISHAY, CRCW040240K2FKED 17 5 R4, R6, R8, R9, R10 RES., 1M, 1/16W, 1%, 0402 VISHAY, CRCW04021M00FKED 18 1 R5 RES., 715k, 1/16W, 1%, 0402 VISHAY, CRCW0402715KFKED 19 1 R7 RES., 374k, 1/16W, 1%, 0402 VISHAY, CRCW0402374KFKED 20 1 R11 RES., 49.9Ω, 1/16W, 1%, 0402 VISHAY, CRCW040249R9FKED 21 0 R12 RES., OPTION, 0402 22 1 U1 I.C.,18V, 2A BUCK-BOOST DC/DC CONVERTER WITH LOW-LOSS DUAL INPUT POWERPATH LINEAR TECHNOLOGY, LTC3118EUFD*PBF 23 12 E1-E12 TP, TURRET, 0.094", MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07-0 24 2 JP1, JP2 CONN., HEADER, 1×3, 2mm SAMTEC, TMM-103-02-L-S 25 2 XJP1-XJP2 SHUNT, 2mm SAMTEC, 2SN-BK-G 26 4 STAND OFF STANDOFF, NYLON, SNAP-ON, 0.625" KEYSTONE, 8834 (SNAP ON) 27 1 PCB, DC2045A DEMO CIRCUIT 2045A-2 28 2 STENCILS, DC2045A (TOP & BOTTOM) STENCILS, DC2045A-2 - TOP & BOTTOM 6 dc2045af DEMO MANUAL DC2045A Schematic Diagram dc2045af 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. 7 DEMO MANUAL DC2045A 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 8 dc2045af Linear Technology Corporation LT 0315 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015