MAX17681EVKITE#

MAX17681 Evaluation Kit General Description The MAX17681E 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. The EV kit operates over a wide inputvoltage range of 17V to 36V and uses primary-side feedback to regulate the output voltage. The EV kit output is programmed to ±15V, 75mA each and ±7.5V, 75mA each with ±10% regulation. The EV kit comes installed with the MAX17681 in a 10-pin (3mm x 2mm) TDFN package. Evaluates: MAX17681 for Isolated ±15V and ±7.5V Output Configuration Quick Start Recommended Equipment ●● One 15V–60V DC, 0.5A power supply ●● Four resistive loads, each 75mA sink capacity ●● Four digital multimeters (DMM) Caution: Do not turn on the power supply until all connections are completed. Test Procedure 1) Verify that J1 is open. Features 2) Set the power supply output to 24V. Disable the power supply. ●● ±15V, 75mA Each and ±7.5V, 75mA Each Continuous Current 3) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the nearest PGND PCB pad. ●● 17V to 36V Input Voltage Range ●● EN/UVLO Input ●● 200kHz Switching Frequency ●● 86.9% Peak Efficiency ●● Overcurrent Protection ●● No Optocoupler ●● Delivers Up to 3.4W Output Power ●● Overtemperature Protection ●● Proven PCB layout Ordering Information appears at end of data sheet. 4) Connect the first resistive load across the +15V PCB pad and the GND0 PCB pad. Connect the second 75mA resistive load across the -15V PCB pad and the GND0 PCB pad. 5) Connect the third 75mA resistive load across the +7V PCB pad and the GND0 PCB pad. Connect the fourth 75mA resistive load across the -7V PCB pad and the GND0 PCB pad. 6) Connect two DMMs configured in voltmeter mode across the ±15V PCB pads and the nearest GND0 PCB pad. Also, connect another two DMMs configured in voltmeter mode across the ±7 PCB pads and the nearest GND0 PCB pad. 7) Enable the input power supply. 8) Verify that output voltages are at ±15V and ±7.5V (with allowable tolerance of ±10%) with respect to GND0. 9) If required, vary the input voltage from 17V to 36V, and the load current from 0mA to 75mA and verify that output voltages are ±15V and ±7.5V. 19-7669; Rev 0; 5/16 MAX17681 Evaluation Kit Evaluates: MAX17681 for Isolated ±15V and ±7.5V Output Configuration Detailed Description The MAX17681E 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 3.4W. The EV kit generates either ±15V or ±7.5V, 75mA each output voltages, from a 17V to 36V input supply. The EV kit features a forced-PWM control scheme that provides constant switching-frequency 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 primary output voltage (VPRI). RESET pulls low if FB voltage drops below 92.5% of its set value. RESET goes high-impedance 1024 clock cycles after 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. Jumper J1 configures the EV kit’s output for turn-on/turn-off control. Install a shunt across jumper J1 pins 2-3 to disable VOUT. See Table1 for proper J1 jumper configurations. NOTE 1: The secondary output diodes D1, D2, D3, and D4 are rated to carry short-circuit current only for few 100’s of ms and is not rated to carry the continuous shortcircuit 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, U3 sinks the minimum load current required to regulate the output voltages within ±10% regulation. Table1. Enable Control (EN/UVLO) (J1) Jumper Settings SHUNT POSITION EN/UVLO PIN VOUT OUTPUT J1 1-2 Connected to VIN Enabled 2-3 Connected to GND Disabled Connected to midpoint of R1, R2 resistor-divider Enabled at VIN ≥ 15.5V Open* *Default position. www.maximintegrated.com Maxim Integrated │  2 MAX17681 Evaluation Kit Evaluates: MAX17681 for Isolated ±15V and ±7.5V Output Configuration EV Kit Performance Report EFFICIENCY vs. LOAD CURRENT 100 toc1 17 90 OUTPUT VOLTAGE (V) EFFICIENCY (%) 70 VIN = 36V 60 50 VIN = 24V 40 30 VIN = 17V 20 VIN = 24V 16 VIN = 36V 15.5 15 14.5 VIN = 17V 14 10 0 10 20 30 40 50 60 13.5 70 0 10 20 OUTPUT VOLTAGE vs. LOAD CURRENT -14 toc3 8 OUTPUT VOLTAGE (V) -15 -15.5 VIN = 36V -16 50 60 70 toc4 +7.5V output VIN = 24V 7.8 VIN = 24V VIN = 17V 40 OUTPUT VOLTAGE vs. LOAD CURRENT 8.2 -15V output -14.5 30 LOAD CURRENT (mA) LOAD CURRENT (mA) OUTPUT VOLTAGE (V) toc2 +15V output 16.5 80 0 OUTPUT VOLTAGE vs. LOAD CURRENT VIN = 36V 7.6 7.4 7.2 7 VIN = 17V 6.8 -16.5 0 10 20 30 40 50 60 70 6.6 LOAD CURRENT (mA) 10 20 30 40 50 60 70 LOAD CURRENT (mA) OUTPUT VOLTAGE vs. LOAD CURRENT -6.8 0 LOAD TRANSIENT RESPONSE (LOAD CURRENT FROM 37mA TO 75mA ON +15V) toc5 toc6 -7.5V OUTPUT OUTPUT VOLTAGE (V) -7 VIN = 24V -7.2 VOUT (AC) VIN = 17V 500mV/div -7.4 -7.6 -8 50mA/div VIN = 36V -7.8 0 10 20 30 40 50 LOAD CURRENT (mA) www.maximintegrated.com IOUT 60 70 1mS/div Maxim Integrated │  3 MAX17681 Evaluation Kit Evaluates: MAX17681 for Isolated ±15V and ±7.5V Output Configuration Component Suppliers SUPPLIER WEBSITE Wurth Electronik www.we-online.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com Note: Indicate that you are using the MAX17681 when contacting these component suppliers. Component Information, PCB Layout, and Schematic See the following links for component information, PCB layout diagrams, and schematic. ●● MAX17681E EV BOM Ordering Information PART TYPE MAX17681EVKITE# EVKIT #Denotes RoHS compliant. ●● MAX17681E EV PCB Layout ●● MAX17681E EV Schematic www.maximintegrated.com Maxim Integrated │  4 MAX17681 Evaluation Kit Evaluates: MAX17681 for Isolated ±15V and ±7.5V Output Configuration Revision History REVISION NUMBER REVISION DATE 0 5/16 DESCRIPTION Initial release PAGES CHANGED — 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. © 2016 Maxim Integrated Products, Inc. │  5 S NO Designation Qty Description 1 1 4.7µF±10%, 50V,X7R Ceramic capacitor   (1206) 1 1µF±10% 16V X7R Ceramic capacitor  (0603) C1 2 C2 3 4 5 6 7 C3 C4 C5 C6 C7 8 1 1 1 1 1 1 C8 9 10 11 12 13 14 15 16 17 18 19 20 C9,C10 C11,C12 C13 D1,D2 D3,D4 J1 R1 R2 R3 R4 R5 R6 2 2 1 0.033µFnF±10%,25V, X7R ceramic  capacitor (0402) 0.047µFnF±10%,25V, X7R ceramic  capacitor (0402) 470pF±5%,50V,COG ceramic capacitor  (0402) 22µF±10%,25V, X5R ceramic capacitor  (1206) 0.01µF±10%, 50V, X7R ceramic capacitor  (0402) 22µF, 20%, 50V, ALUMINUM  ELECTROLYTIC CAPACITOR 6.60*6.60mm, 4.7µF±10%,16V,  X7R ceramic capacitor  (1206) 2.2µF±10%,50V,  X7R ceramic capacitor  (1206) 1000pF±10%,1500V,  X7R ceramic  capacitor (1206) 2 200V/1A, PowerDI®123 2 100V/2A, PowerDI®123 1 3‐pin headers 1 3.01M Ohm±1%  resistor (0402)  1 261K Ohm±1%  resistor (0402)  1 86.6K Ohm±1%  resistor (0402)  1 11kΩ ±1% resistor (0402)  1 7.15kΩ ±1% resistor (0402)  1 100kΩ ±5% resistor (0402) Mfg Part #1 Mfg Part #2 Mfg Part #3 Mfg Part #4 KEMET C0603C105K4RAC TDK  C1608X7R1C105 TAIYO YUDEN  K EMK107B7105KA Murata GRM31CR71H475KA12 Murata GRM188R71C105KA12 Murata GRM155R71E333KA88 TDK C1005X7R1E473K Murata GCM1555C1H471JA16 Murata GRM155R71E473K KEMET  GRM1555C1H471JA01 Murata GRM31CR61E226K Murata GRM155R71H103KA88 KEMET C0402C103K5RAC Panasonic EEEFK1H220P Murata GRM31CR71C475K Murata GRM31CR71H225KA88 AVX 1206SC102KAT DIODES INCORPORATED  DFLS1200 DIODES INCORPORATED  DFLS2100 SULLINS ELECTRONICS CORP  PEC03SAAN VISHAY DALE CRCW04023M01FK VISHAY DALE CRCW0402261KFK VISHAY DALE CRCW040286K6FK VISHAY DALE CRCW040211K0FK VISHAY DALE CRCW04027K15FK PANASONIC ERJ‐2GEJ104X TAIYO YUDEN  UMK316B7225K 21 R7 1 OPEN (0402) 22 R8,R11 2 22Ω ±1% resistor (0402) 23 R9 1 604kΩ ±1% resistor (0402) 1 115kΩ ±1% resistor (0402) 1 294kΩ ±1% resistor (0402) 1 24.9kΩ ±1% resistor (0402) 2 4.7kΩ ±5% resistor (0603) 2 10kΩ ±5% resistor (0603) 24 25 26 27 28 R10 R12 R13 R14,R15 R16,R17 29 T1 1 30 U1 1 31 U2,U3 2 EP13,10‐pin SMT, 50μ,(5-1):(6-7) :(7-8):(8-9):(9-10)=1:1 MAX17681 TDFN10 3*2mm Iso buck DCDC converter Shunt regulator SOT25 VISHAY DALE CRCW040222R0FK PANASONIC ERJ-2RKF6043X VISHAY DALE CRCW0402115KFK VISHAY DALE CRCW0402294KFK VISHAY DALE CRCW040224K9FKEDHP PANASONIC ERJ-3GEYJ472V VISHAY DALE CRCW060310K0JN WURTH ELECTRONICS INC 750342864 MAX17681ATB+ DIODES INCORPORATED TL431BW5 PANASONIC ERJ-3GEYJ103V TOP SILKSCREEN TOP BOTTOM A VPRI D1 C +15V +7V T1 1 7 8 U1 4.7UF 1 1 + 22UF 2 VIN VIN EN/UVLO 1 R1 C2 3.01M 2 3 J1 1UF C7 0.01UF R2 261K 3 VCC 9 MAX17681ATB+ PGND LX VIN GND EN/UVLO 4 VCC 5 FB RESET 10 10 VCC 9 8 RESET COMP 7 SS 6 EP 11 C1 C8 C6 R5 100K 22UF R3 86.6K RESET 9 10 C D4 4.7K GND0 22 A DFLS2100 C10 4.7UF 4.7K 2 1 R7 U2 4 R9 604K GND0 C12 2.2UF R10 115K R12 R17 10K 294K 2 1 U3 4 R13 24.9K 0.047UF D2 R4 11K EN/UVLO C13 1000PF RESET SGND 22 GND0 R15 -7V C3 R11 10K C C4 0.033UF R16 GND0 7.15K 470PF R8 R14 2.2UF DFLS2100 PACKOUT SGND EN/UVLO 8 A 4.7UF 750342864 R6 C5 7 D3 C9 5 2 PGND C11 6 3 6 5 1 5 3 5 PGND PGND GND0 A C -15V