Development Board EPC9118 Quick Start Guide

Development BoardEPC9118Quick Start GuideEPC2001C/EPC202148 V Buck ConverterRevision 1.0

QUICK START GUIDEDESCRIPTIONThe EPC9118 demonstration board is a 5 V output, 400 kHz buck converterwith a 20 A maximum output current [25 A with convection cooling] and30 V to 60 V input voltage range (48 V nominal). The demonstration boardfeatures the EPC2001C/ EPC2021 enhancement mode (eGaN ) field effecttransistors (FETs), as well as the LTC3891 Buck controller intended for usewith MOSFETs.The EPC9118 board contains the complete power stage (including eGaNFETs, driver, inductor and input/output caps) in a compact 1” x 1.3” layoutto showcase the performance that can be achieved using the eGaN FETsand a traditional MOSFET controller together.The EPC9118 demonstration board is 2 ½” square and contains a fullyclosed-loop buck converter with optimized control loop.There are also various probe points to facilitate efficiency calculation.A complete block diagram of the circuit is given in figure 1. For moreinformation on the EPC2001C/EPC2021 eGaN FETs or LTC3891 controller,please refer to the datasheet available from EPC at epc-co.com andlinear.com. These datasheets should be read in conjunction with thisquick start guide.Demonstration System EPC9118Table 1: Performance Summary (TA 25 C)SymbolParameterVINIOUTBus Input VoltageRangeSwitch Node OutputVoltageSwitch Node OutputCurrentfSWSwitching Frequency400kHzUVLOUnder Voltage LockOut on VIN, Rising29V92.8%92.3%VOUTPeak EfficiencyFull Load EfficiencyMin Typ Max Units30605V20*48 VIN, 13 A IOUT , 200LFM48 VIN, 20 A IOUT , 200LFMVA* Maximum limited by thermals.VIN30 V -EXT60VCCVEXT VCCEXT VCCLTC3891controllerQUICK START PROCEDUREDemonstration board EPC9118 is easy to set up to evaluate the performance of the EPC2001C/EPC2021 eGaN FETs and directly drivenfrom the controller IC. Refer to figure 2 for proper connect andmeasurement setup and follow the procedure below:ConditionsVOUT5 V / 0-20 AGNDGND1. With power off, connect the input power supply bus between VIN andGND banana jacks as shown.Figure 1: Block diagram of demonstration board2. With power off, connect the active (constant current) load asdesired between VOUT and GND banana jacks as shown.3. Turn on the supply voltage beyond UVLO to the required value(do not exceed the absolute maximum voltage of 60 V on VIN ).5. Turn on active load to the desired load current while staying belowthe maximum current (20 A)6. Once operational, adjust the bus voltage and load current within theallowed operating range and observe the output switching behavior,efficiency and other parameters.IOUTIIN4. Measure the output voltage to make sure the board is fullyfunctional and operating no-load.AAA 60 VVIN supply– – VVINVOUT–V 20AActive load7. For shutdown, please follow steps in reverse.NOTE. When measuring the high frequency content switch node, care must betaken to avoid long ground leads. Measure the switch node by placing the oscilloscope probe tip on the top pad and bottom pads of D2. See figure 3 for properscope probe technique. Measuring the switch node with a high bandwidth ( 500MHz) probe and high bandwidth scope ( 1GHz) is recommended.EPC – POWER CONVERSION TECHNOLOGY LEADER EPC-CO.COM 2020 Figure 2: Proper connection and measurement setup 2

QUICK START GUIDEDemonstration System EPC9118Do not use probe ground leadDo not let probe tiptouch the low-side die!Minimize loopD2Place probetip on padFigure 3: Proper measurement of switch nodeFigure 4: Typical waveforms for 48 V to 5 V / 20 A (400 kHz) CH4: switch node voltageEPC – POWER CONVERSION TECHNOLOGY LEADER EPC-CO.COM 2020 3

QUICK START GUIDEDemonstration System EPC9118CIRCUIT PERFORMANCETHERMAL CONSIDERATIONSThe EPC9118 demonstration circuit was designed to showcase the sizeand performance that can readily be achieved at 400 kHz operation usingeGaN FETs for supply voltages up to 48 V or more. Since a closed loopcontroller is included on board, the associated losses must also be lumpedinto any efficiency measurement that is performed. In an effort to mitigatethese losses and focus on the efficiency of the power stage, the controlleris powered directly from the output. Thus the controller and gate drivelosses are still included, but the associated conversion loss from the inputsupply is improved.The EPC9118 demonstration board thermal image for steady state fullload operation is shown in figure 6. The EPC9118 is intended for benchevaluation with low ambient temperature and convection cooling.The addition of heat-sinking and forced air cooling could increase thecurrent capability of the demonstration circuit, but care must be takento not exceed the absolute maximum die temperature of 150 C and staywithin the constraints of the other components within the circuit, mostnotably the saturation of the output inductor.NOTE. The EPC9118 demonstration board does not have any thermal protectionon board.9636 V9448 VEfficiency (%)9256 V9088868482800510152025Output Current (A)Figure 5: Typical efficiency curves for 36 V, 48 V and 56 V inputshort term operation above 20 AFigure 6: Thermal image of EPC9118 under full load condition: 48 VIN , 20 AOUT with minimal airflowEPC – POWER CONVERSION TECHNOLOGY LEADER EPC-CO.COM 2020 4

QUICK START GUIDEDemonstration System EPC9118Table 2: Bill of MaterialsItemQtyReferencePart DescriptionManufacturerPart Number14C1, C2, C3, C4Capacitor, 4.7 µF, 100 V, 10%, X7STDKCGA6M3X7S2A475K200AB22C6, C7Capacitor, 1 µF, 25 V 10%, X5RMurataGRM188R61E105KA12D31C9Capacitor, 100 nF, 100 V, 10%, X7RMurataGRM188R72A104KA35D41C12Capacitor, 4.7 nF, 10%, 50 V, X7RMurataGRM1885C1H472JA01D51C14Capacitor, 22 pF, 5%, 50 V, NP0MurataGRM1885C1H220JA01D61C21Capacitor, 1000 pF, 5%, 50 V, NP0MurataGRM1885C1H102JA01D74C10, C18, C19, C20Capacitor, 1 µF, 100 V, 10%, X7STDKCGA4J3X7S2A105K125AE82C8, C13Capacitor, 100 nF, 25 V, 10%, X5RTDKC1005X5R1E104K93C15, C16, C17Capacitor, 47 µF, 10 V, 20%, X5RTDKC2012X5R1A476M125AC101D1Schottky Diode, 100 V, 200 mASTMicroelectronicsBAT41KFILM111D2Schottky Diode, 100 V, 2ADiodes Inc.DFLS2100121D3Zener, 5.1 V, 150 mWBourns Inc.CD0603-Z5V1137E1, E2, E3, E6, E7, E9, E10Test PointKeystone5015144J1, J2, J3, J4Banana Jacks, FemaleKeystone575-4151L1Inductor, 1.2 µH, 20%, 36 N FETEPCEPC2001C171Q2eGaN FETEPCEPC2021181R1Resistor, 2.2 Ω, 1% 1/16 WYageoRC0402FR-072R2L195R2, R18, R19, R23, R24Resistor, 0 Ω, 1/16 WStackpoleRMCF0402ZT0R00201R4Resistor, 100 K, 1%, 1/16 WStackpoleRMCF0402FT100K211R14Resistor, 470 K, 1%,1/10 WStackpoleRMCF0603FT470K221R17Resistor, 3.32 K, 1%,1/10 WStackpoleRMCF0603FT3K32231R5Resistor, 105 K, 1%, 1/10 WStackpoleRMCF0603FT105K241R6Resistor, 61.9 K, 1%, 1/10 WStackpoleRMCF0603FT61K9252R7, R16Resistor, 20 K, 1%,1/10 WStackpoleRMCF0603FT20K0261R8Resistor, 0 Ω, 1/10 WStackpoleRMCF0603ZT0R00271R11Resistor, 10 Ω, 1%, 1/16 WStackpoleRMCF0402FT10R0281R13Resistor, 6.49 K, 0.1%, 1/10 WStackpoleRMCF0603FT6K49Linear TechnologyLTC3891EUDC291U1PWM buck controller300C5, C11Optional310R20, R21, R22OptionalEPC – POWER CONVERSION TECHNOLOGY LEADER EPC-CO.COM 2020 5

QUICK START GUIDEEPC – POWER CONVERSION TECHNOLOGY LEADER EPC-CO.COM 2020 E1VINVINJ1VIN30 V - 60 VJ2GNDR1C1 C2C3 C44.7µF100V1210VIN 2.2C9100nF100VINTVCCR20 OHM0402GNDN2R4100kE2LTC3891EUDCPGOODVOUTE317R80 -TRACK/SSPLLMODE 1SENSE 14BOOSTSGNDPGNDTGR21OPTSENSE 0603R720.0KC6R13C211000pF50VR1112 BOOST1010ILIMBG11136.49KINTVCCBAT41KR230 OHM0402VINQ1EPC2001CC10 C18C19 G R240 SENSE-SGNDINTVCCR190 OHMS04025ITH21R22OPTE10R661.9KC8100nFRUNR180 620.0kFREQINTVCCC71µFVINVINC5OPT1.2µHSER2010 122MLD2DFLS2100J3VOUTC15C16C1747µF10 V0805E7Development Board SchematicEPC9118Revision 1.1GNDGNDDemonstration System EPC9118J45 V / 20 A 6

For More Information:Please contact info@epc-co.comor your local sales representativeVisit our website:epc-co.comSign-up to receiveEPC updates atbit.ly/EPCupdatesor text “EPC” to 22828EPC Products are distributed through Digi-Key.www.digikey.comDemonstration Board NotificationThe EPC9118 board is intended for product evaluation purposes only. It is not intended for commercial use nor is it FCC approved for resale. Replace components on theEvaluation Board only with those parts shown on the parts list (or Bill of Materials) in the Quick Start Guide. Contact an authorized EPC representative with any questions. This board isintended to be used by certified professionals, in a lab environment, following proper safety procedures. Use at your own risk.As an evaluation tool, this board is not designed for compliance with the European Union directive on electromagnetic compatibility or any other such directives or regulations. As boardbuilds are at times subject to product availability, it is possible that boards may contain components or assembly materials that are not RoHS compliant. Efficient Power Conversion Corporation (EPC) makes no guarantee that the purchased board is 100% RoHS compliant.The Evaluation board (or kit) is for demonstration purposes only and neither the Board nor this Quick Start Guide constitute a sales contract or create any kind of warranty, whether expressor implied, as to the applications or products involved.Disclaimer: EPC reserves the right at any time, without notice, to make changes to any products described herein to improve reliability, function, or design. EPC does not assume any liabilityarising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, or other intellectual property whatsoever, nor therights of others.

quick start guide. QUICK START PROCEDURE Demonstration board EPC9118 is easy to set up to evaluate the per-formance of the EPC2001C/EPC2021 eGaN FETs and directly driven from the controller IC. Refer to figure 2 for proper connect and measurement setup and follow the procedure below: 1.