MAX17681EVKITF#

Click here for production status of specific part numbers. MAX17681EVKITF# Evaluation Kit General Description The MAX17681EVKITF is a fully assembled and tested circuit board that demonstrates the performance of the MAX17681 high-efficiency, iso-buck DC-DC Converter. The EV kit operates over a wide input-voltage range of 17V to 36V and uses primary-side feedback to regulate the output voltage. The EV kit output is programmed to +24V at 100mA, with ±8% output voltage regulation. The EV kit comes installed with the MAX17681 in a 10-pin (3mm x 2mm) TDFN package. Features Evaluates: MAX17681 for Isolated +24V Output Configuration Quick Start Recommended Equipment ●● One 15V to 60V DC, 0.5A power supply ●● One resistive load 100mA sink capacity ●● Two digital multimeters (DMM) Caution: Do not turn on the power supply until all connections are completed. Test Procedure The EV kit comes with the default output configuration programmed to +24V. ●● 17V to 36V Input-Voltage Range 1) Verify that J1 is open. ●● +24V, 100mA Continuous Current 2) Verify that R7 is not installed. ●● EN/UVLO Input 3) Set the power supply output to 24V. Disable the power supply. ●● 200kHz Switching Frequency ●● Overcurrent Protection ●● No Optocoupler ●● Delivers up to 2.4W Output Power ●● Overtemperature Protection ●● Proven PCB Layout 4) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the nearest PGND PCB pad. Connect a 100mA resistive load across the +24V PCB pad and the GND0 PCB pad. 5) Connect a DMM configured in voltmeter mode across the +24V PCB pad and the nearest GND0 PCB pad. 6) Enable the input power supply. Ordering Information appears at end of data sheet. 7) Verify that output voltage is at +24V (with allowable tolerance of ±8%) with respect to GND0. 8) If required, vary the input voltage from 17V to 36V, the load current from 0mA to 100mA, and verify that output voltage is at +24V (with allowable tolerance of ±8%). 19-8438; Rev 2; 5/18 Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681EVKITF# Evaluation Kit Detailed Description The MAX17681EVKITF evaluation kit (EV kit) is a fully assembled and tested circuit board that demonstrates the performance of the MAX17681 high efficiency, iso-buck DC-DC converter designed to provide an isolated power up to 2.4W. The EV kit generates +24V, 100mA from a 17V to 36V input supply. The EV kit features a forced PWM control scheme that provides constant switchingfrequency of 200kHz operation at all load and line conditions. The EV kit includes an EN/UVLO PCB pad to monitor and program the EN/UVLO pin of the MAX17681. The VPRI PCB pad helps measure the regulated primary output voltage (VPRI). An additional RESET PCB pad is available for monitoring the health of the primary output voltage (VPRI). RESET is pulled low if the FB voltage drops below 92.5% of its set value. RESET goes high impedance 1024 clock cycles after the FB voltage rises above 95.5% of its set value. The programmable soft-start feature allows users to reduce the input inrush current. The iso-buck is a synchronous-buck-converter-based topology, useful for generating isolated outputs at low power level without using an optocoupler. The detailed procedure for setting the soft-start time, ENABLE/UVLO divider, primary output voltage (VPRI) selection, adjusting the primary output voltage, primary inductance selection, turns-ratio selection, output capacitor selection, output diode selection, and external loop compensation are given in the MAX17681 IC data sheet. Enable Control (J1) The EN/UVLO pin on the device serves as an on/off control while also allowing the user to program the input undervoltage-lockout (UVLO) threshold. J1 configures the EV kit’s output for turn-on/turn-off control. Install a shunt across J1 pins 2-3 to disable VOUT. See Table 1 for proper J1 configurations. NOTE 1: The secondary output diodes D1 is rated to carry short-circuit current only for a few 100’s of ms and is not rated to carry the continuous short-circuit current. NOTE 2: The iso-buck converter typically needs 10% minimum load to regulate the output voltage. In this design when the +24V rail is healthy, the U2 sinks the minimum load current required to regulate the output voltages within ±8% regulation. Table 1. Enable Control (EN/UVLO) (J1) Jumper Settings SHUNT POSITION EN/UVLO PIN VOUT J1 1-2 Connected to VIN Always Enabled 2-3 Connected to GND Always Disabled Connected to midpoint of R1, R2 resistor-divider Enabled at VIN ≥ 15.5V Open* *Default position. www.maximintegrated.com Maxim Integrated │  2 Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681EVKITF# Evaluation Kit EV Kit Performance Report EFFICIENCY vs. LOAD CURRENT toc1 OUTPUT VOLTAGE vs. LOAD CURRENT 25.5 +24V OUTPUT 90 25.0 70 OUTPUT VOLTAGE (V) EFFICIENCY (%) 80 VIN = 36V 60 VIN = 24V 50 VIN = 17V 40 30 20 10 0 +24V OUTPUT 0 10 20 30 40 50 60 70 80 VIN = 36V 24.5 24.0 VIN = 17V 23.5 23.0 90 100 VIN = 24V toc2 100 0 10 LOAD CURRENT (mA) 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA) LOAD TRANSIENT RESPONSE (LOAD CURRENT FROM 50mA TO 100mA ON +24V) toc3 VOUT (AC) 1V/div 50mA/div IOUT 400µs/div www.maximintegrated.com Maxim Integrated │  3 MAX17681EVKITF# Evaluation Kit Ordering Information Component Suppliers SUPPLIER Wurth Electronik Evaluates: MAX17681 for Isolated +24V Output Configuration WEBSITE www.we-online.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com PART MAX17681EVKITF# TYPE EVKIT #Denotes RoHS compliant. Note: Indicate that you are using the MAX17681 when contacting these component suppliers. www.maximintegrated.com Maxim Integrated │  4 www.maximintegrated.com T1 U1 U2 24 25 J1 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 C10 D1 C9 C8 C7 C6 C5 C4 C3 C2 C1 23 13 14 15 16 17 18 19 20 21 22 12 11 10 9 8 7 6 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 MAX17681 TDFN10 3*2mm Iso buck DC-DC converter Shunt regulator SOT25 EP10, 8-pin SMT, 80µH,1.2A,2.4:1 3.01M Ohm±1% resistor (0402) 261K Ohm±1% resistor (0402) 110K Ohm±1% resistor (0402) 10.5kΩ ±1% resistor (0402) 3.74kΩ ±1% resistor (0402) 100kΩ ±5% resistor (0402) OPEN (0402) 22Ω ±1% resistor (0402) 90.9kΩ ±1% resistor (0402) 10kΩ ±1% resistor (0402) 3-pin headers 1000pF±10%, 1500V, X7R ceramic capacitor (1206) 200V/1A, PowerDI®123 2.2uF±10%,50V, X7R ceramic capacitor (1206) 0.01uF±10%, 50V, X7R ceramic capacitor (0402) 22uF, 20%, 50V, ALUMINUM ELECTROLYTIC CAPACITOR 6.60*6.60mm, 10uF±10%,16V, X7R ceramic capacitor (1206) 820pF±5%,50V,X7R ceramic capacitor (0402) 0.033UFnF±10%,25V, X7R ceramic capacitor (0402) 0.082UFnF±10%,16V, X7R ceramic capacitor (0402) 1µF±10% 16V X7R Ceramic capacitor (0603) 1µF±10%, 50V,X7R Ceramic capacitor (1206) S NO Designation Qty Description MAX17681ATB+ Diode Inc. TL431BW5 WURTH ELECTRONICS INC. 750342860 VISHAY DALE CRCW040222R0FK PANASONIC ERJ-2RKF9092X VISHAY DALE CRCW040210K0JN AVX 1206SC102KAT Diode Inc. DFLS2100-7 SULLINS ELECTRONICS CORP PEC03SAAN VISHAY DALE CRCW04023M01FK VISHAY DALE CRCW0402261KFK VISHAY DALE CRCW0402110KFK PANASONIC ERJ-2RKF1052 PANASONIC ERJ2RKF3741 PANASONIC ERJ-2GEJ104X Murata GRM31CR71H225KA88 Panasonic EEEFK1H220P Murata GRM155R71H103KA88 Murata GRM31CR71C106KAC7 Murata GRM155R71H821K Murata GRM155R71C823K Murata GRM155R71E333KA88 Murata GRM188R71C105KA12 Murata GRM31CR71H105KA61 Manufacturer Partnumber-1 TAIYO YUDEN UMK316B7225K KEMET C0402C103K5RAC KEMET C0402C821K5RAC KEMET C0402C823K4RAC KEMET C0603C105K4RAC KEMET C1206C105K5RAC Manufacturer Partnumber-2 TDK C1608X7R1C105K Murata GRM31MR71H105KA88 Manufacturer Partnumber-3 TAIYO YUDEN EMK107B7105KA Manufacturer Partnumber-4 MAX17681EVKITF# Evaluation Kit Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681 EV Kit Bill of Materials Maxim Integrated │  5 RESET EN/UVLO SGND VIN PGND 2 + J1 1 C8 22UF 1 3 www.maximintegrated.com R1 C7 3.01M RESET EN/UVLO 0.01UF 2 1UF C1 261K R2 1UF C2 EN/UVLO VIN VCC 5 4 3 2 1 FB VCC EN/UVLO VIN EP 9 8 7 6 GND RESET COMP SS 0.033UF C3 RESET 10 LX U1 MAX17681ATB+ PGND 820PF C5 SGND 0.082UF C4 3.74K R5 100K R6 VCC 10UF C6 PGND 10.5K R4 110K R3 1 PRI 4 1000PF C10 750342860 PGND R7 PACKOUT 1 4 T1 5 8 5 GND0 8 SEC A D1 C U2 2 1 4 22 R8 3 11 VPRI 10K R10 90.9K R9 2.2UF C9 GND0 GND0 +24V MAX17681EVKITF# Evaluation Kit Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681 EV Kit Schematic 5 Maxim Integrated │  6 MAX17681EVKITF# Evaluation Kit Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681 EV Kit PCB Layout Diagrams MAX17681 EV Kit—Top Silkscreen MAX17681 EV Kit—Top www.maximintegrated.com Maxim Integrated │  7 MAX17681EVKITF# Evaluation Kit Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681 EV Kit PCB Layout Diagrams (continued) MAX17681 EV Kit—Bottom www.maximintegrated.com Maxim Integrated │  8 Evaluates: MAX17681 for Isolated +24V Output Configuration MAX17681EVKITF# Evaluation Kit Revision History REVISION NUMBER REVISION DATE 0 3/16 1 4/16 2 5/18 PAGES CHANGED DESCRIPTION Initial release Updated General Description, Test Procedure, Detailed Description, and Enable Control (J1) sections, and Bill of Materials Updated title and the Bill of Materials — 1–2 1–9 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2018 Maxim Integrated Products, Inc. │  9