MAX17681EVKITB#

MAX17681 Evaluation Kit General Description The MAX17681EVKITB 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 has two output configurations. In configuration one the output is programmed to ±7V@100mA, with ±8% output voltage regulation. The second configuration uses a post regulator, MAX17651 to produce ±5V@50mA with < ±3% regulation. The EV kit comes installed with the MAX17681 in a 10-pin (3mm x 2mm) TDFN package and MAX17651 in a 6-lead TSOT package. Features ●● 17V to 36V Input Voltage Range ●● ±7V, 100mA or ±5V, 50mA Continuous Current ●● EN/UVLO Input ●● 200kHz Switching Frequency ●● 87.5% Peak Efficiency ●● Overcurrent Protection ●● No Optocoupler ●● Delivers up to 1.4W Output Power ●● Overtemperature Protection ●● Proven PCB Layout Ordering Information appears at end of data sheet. Evaluates: MAX17681 for Isolated ±7V or ±5V Output Configuration Quick Start Recommended Equipment ●● One 15V–60V DC, 0.5A power supply ●● Two resistive loads of 50mA to 100mA sink capacity ●● Four digital multimeters (DMM) Caution: Do not turn on the power supply until all connections are completed. Procedure The EV kit comes with the default output configuration programmed to ±7V. Test Procedure for ±7V Output 1) Verify that the J1 is open. 2) Verify that the R17, R18, and R19 are not installed. 3) Set the power supply output to 24V. Disable the power supply. 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 +7V PCB and GND0 PCB pads. Connect another 100mA resistive load across the GND0 PCB and -7VPCB pads. 5) Connect a DMM, configured in voltmeter mode, across the +7V PCB pad and the nearest GND0 PCB pad. Connect another DMM configured in voltmeter mode across the -7V PCB pad and the nearest GND0 PCB pad. 6) Enable the input power supply. 7) Verify that output voltages are at ±7V (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 voltages are ±7V (with allowable tolerance of ±8%). 19-8443; Rev 1; 5/16 MAX17681 Evaluation Kit Evaluates: MAX17681 for Isolated ±7V or ±5V Output Configuration Test Procedure for ±5V Output 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. The post regulator, MAX17651 output voltage setting and the related additional information are detailed in MAX17651 IC data sheet. 1) Verify that J1 is open 2) Remove R16 and R10. Place 0Ω resistors in R18 and R19. 3) Set the input power supply output to 24V. Disable the power supply. 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 50mA resistive load across the +5V PCB pad and the GND0 PCB pad. Connect another 50mA resistive load across the GND0 PCB pad and the -5VPCB pad. 5) Connect a DMM, configured in voltmeter mode, across the +5V PCB pad and the nearest GND0 PCB pad. Connect another DMM, configured in voltmeter mode, across the -5V PCB pad and the nearest GND0 PCB pad. 6) Enable the input power supply. 7) Verify that output voltages are at ±5V (with allowable tolerance of ±3%) with respect to GND0. 8) If required, vary the input voltage from 17V to 36V, the load current from 0mA to 50mA, and verify that output voltages are ±5V (with allowable tolerance of ±3%). Detailed Description The MAX17681EVKITB 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 1.4W. The EV kit generates either ±7V, 100mA or ±5V, 50mA output, 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 is pulled low if the FB voltage drops below 92.5% of its set value. RESET goes high 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. www.maximintegrated.com 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 J1 pins 2-3 to disable VOUT. See Table 1 for proper J1 configurations. Table 1. Enable Control (EN/UVLO) (J1) Jumper Settings SHUNT POSITION EN/UVLO PIN VOUT OUTPUT 1-2 Connected to VIN Always Enabled 2-3 Connected to GND Always Disabled Open* Connected to midpoint of R1, R2 resistor-divider Enabled at VIN ≥ 15.5V J1 *Default position. NOTE 1: The secondary output diodes D1, D2 are rated to carry short-circuit current only for a few hundredths of a millisecond and are 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 both +7V and -7V rails are healthy, the U4 sinks the minimum load current required to regulate the output voltages within ±8% regulation. When a short is applied on any one of the output rails with no-load on other healthy rail, the healthy rail voltage can be as high as 16V. Maxim Integrated │  2 Evaluates: MAX17681 for Isolated ±7V or ±5V Output Configuration MAX17681 Evaluation Kit EV Kit Performance Report EFFICIENCY vs. LOAD CURRENT toc1 90 70 OUTPUT VOLTAGE (V) EFFICIENCY (%) +7V output 7.8 80 VIN = 36V 60 VIN = 24V 50 VIN = 17V 40 30 20 7.6 VIN = 17V 7.4 VIN = 24V VIN = 36V 7.2 7.0 10 0 OUTPUT VOLTAGE vs. LOAD CURRENT 8.0 toc2 100 ±7V output 0 10 20 30 40 50 60 70 80 6.8 90 100 0 20 OUTPUT VOLTAGE vs. LOAD CURRENT -6.8 60 80 100 OUTPUT VOLTAGE vs. LOAD CURRENT 5.01 +5V OUTPUT 5.005 -7 toc4 toc3 -7V OUTPUT 40 LOAD CURRENT (mA) LOAD CURRENT (mA) VIN = 17V -7.4 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 5 -7.2 VIN = 24V VIN = 36V -7.6 -7.8 -8 VIN = 36V 4.985 4.98 4.975 0 20 40 60 80 100 4.97 10 20 30 40 50 LOAD TRANSIENT RESPONSE (LOAD CURRENT FROM 50mA TO 100mA ON +7V, -7V LOADED WITH 100mA ) -4.985 +7V OUTPUT VOUT (AC) -4.99 toc6 toc5 -5V OUTPUT -4.98 0 LOAD CURRENT (mA) OUTPUT VOLTAGE vs. LOAD CURRENT -4.975 OUTPUT VOLTAGE (V) VIN = 17V 4.99 LOAD CURRENT (mA) 200mV/div VIN = 36V -4.995 VIN = 24V -5 -5.005 50mA/div VIN = 17V IOUT -5.01 -5.015 VIN = 24V 4.995 0 10 20 30 40 50 1mS/div LOAD CURRENT (mA) www.maximintegrated.com Maxim Integrated │  3 MAX17681 Evaluation Kit Evaluates: MAX17681 for Isolated ±7V or ±5V Output Configuration Component Suppliers Ordering Information SUPPLIER WEBSITE Wurth Electronik www.we-online.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com PART TYPE MAX17681EVKITB# EV Kit #Denotes RoHS compliant. Note: Indicate that you are using the MAX17681 when contacting these component suppliers. Component List, PCB Layout, and Schematic See the following links for component information, PCB files, and schematic. ●● MAX17681B EV BOM ●● MAX17681B EV PCB Layout ●● MAX17681B EV Schematic www.maximintegrated.com Maxim Integrated │  4 Evaluates: MAX17681 for Isolated ±7V or ±5V Output Configuration MAX17681 Evaluation Kit Revision History REVISION NUMBER REVISION DATE 0 2/16 Initial release 1 5/16 Updated General Description section DESCRIPTION PAGES CHANGED — 1, 2 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. © 2016 Maxim Integrated Products, Inc. │  5 S NO Designation Qty Description 1 Murata GRM31CR71H105KA61 KEMET C1206C105K5RAC Murata GRM31MR71H105KA88 1 1µF±10% 16V X7R Ceramic capacitor (0603) Murata GRM188R71C105KA12 KEMET C0603C105K4RAC TDK C1608X7R1C105K 1 33nF±10%,25V, X7R ceramic Murata capacitor (0402) GRM155R71E333KA88 1 0.082uF±10%,16V, X7R ceramic capacitor (0402) 1 820pF±5%,50V,COG ceramic KEMET capacitor (0402) Murata GRM1555C1H821J C0402C821J5GAC 1 10uF±10%,16V, X7R ceramic Murata capacitor (1206) GRM31CR71C106KAC7 2 4.7uF±10%,50V, X7R ceramic Murata capacitor (1206) GRM31CR71H475KA12 2 2.2uF±10%,50V, X7R ceramic capacitor (1206) 1 C11 1000PF ±10%,1500V, X7R ceramic capacitor (1206) C12, C13 2 0.1uF±10%, 25V, X7R ceramic capacitor(0402) AVX 1206SC102KAT Murata GRM155R71E104KE14 1 0.01uF±10%, 50V, X7R ceramic capacitor (0402) Murata GRM155R71H103KA88 1 22uF, 20%, 50V, ALUMINUM ELECTROLYTIC CAPACITOR 6.60*6.60mm, 3 C3 4 C4 5 C5 6 C6 7 C7, C8 8 C9, C10 9 11 C14 12 C15 13 14 Manufacturer Partnumber-3 1µF±10%, 50V,X7R Ceramic capacitor (1206) C2 10 Manufacturer Partnumber-2 1 C1 2 Manufacturer Partnumber-1 D1, D2 J1 KEMET Murata C0402C823K4RAC C0402C823K4RAC Murata GRM31CR71H225KA88 Panasonic EEEFK1H220P 2 100V/1A, PowerDI®123 1 3-pin headers Diode Inc. DFLS1100-7 SULLINS ELECTRONICS CORP PEC03SAAN TAIYO YUDEN UMK316B7225K KEMET C0402C103K5RAC Manufacturer Partnumber-4 TAIYO YUDEN EMK107B7105KA 15 16 17 18 19 20 21 22 23 24 25 R1 R2 R3 R4 R5 R6 R7, R9 R8 R10 R11 R12, R14 26 1 1 1 3.01M Ohm±1% resistor (0402) 261K Ohm±1% resistor (0402) 78.7K Ohm±1% resistor (0402) 1 10.5kΩ ±1% resistor (0402) 1 4.02kΩ ±1% resistor (0402) 1 100kΩ ±5% resistor (0402) 2 22kΩ ±1% resistor (0402) 1 115kΩ ±1% resistor (0402) 1 22Ω ±1% resistor (0402) 1 604kΩ ±1% resistor (0402) 2 432kΩ ±1% resistor (0402) 2 59kΩ ±1% resistor (0402) 1 0Ω ±5% resistor (0805) R13, R15 27 R16 VISHAY DALE CRCW04023M01FK VISHAY DALE CRCW0402261KFK VISHAY DALE CRCW040278K7FK PANASONIC ERJ-2RKF1052 VISHAY DALE PANASONIC ERJCRCW04024K02FK 2RKF4021X PANASONIC ERJ-2GEJ104X VISHAY DALE CRCW040222K0FK VISHAY DALE CRCW0402115KFK VISHAY DALE CRCW040222R0FK PANASONIC ERJ2RKF6043X VISHAY DALE CRCW0402432KFK VISHAY DALE CRCW040259K0FK YAGEO PHYCOMP RC0805JR-070RL 28 R17 1 OPEN (0402) 29 R18, R19 2 OPEN (0402) 30 T1 1 EP7, 8-pin SMT, 50µH,1.2A, (1-4):(5-6):(7-8) = 1:1 WURTH ELECTRONICS INC. 750342779 31 U1 1 MAX17681 TDFN10 3*2mm Iso buck DC-DC converter MAX17681ATB+ 32 U2,U3 1 MAX17651 TSOT LDO MAX17651AZT+ 33 U4 1 Shunt regulator SOT25 Diode Inc. TL431BW5 VENKEL LTD CR0402-16W5902FT 8 7 6 5 4 3 1 2 +7V D A D1 VPRI OPEN C7 C12 0.1UF R9 R10 4.7UF 22K 22 T1 U1 1UF 1 + 22UF VIN VIN EN/UVLO C2 3.01M 2 3 J1 C14 0.01UF VCC 1UF R2 1 PGND 2 VIN 3 LX GND EN/UVLO 4 VCC 5 FB RESET 10 261K 1 VCC 8 COMP 7 SS 6 R6 RESET R5 C5 C6 100K 4.02K 820PF 6 7 6 7 8 8 10UF R3 78.7K OUT 2 GND PGOOD 5 1 EN 6 FB +5V R12 432K C9 2.2UF MAX17651AZT+ 59K GND0 R16 GND0 GND0 GND0 R19 R17 C8 OPEN 4.7UF 2 1 R11 C4 C D2 C13 604K U4 R7 4 C U3 OPEN 0.082UF C3 IN 4 R13 750342779 9 EP 11 1 R1 1 MAX17681ATB+ 5 3 C1 C15 C 5 22K 5 2 PGND 4 3 GND0 0 4 D U2 R18 C 0.1UF 3 IN OUT 4 2 GND PGOOD 5 EN 6 1 FB C10 R14 2.2UF 432K MAX17651AZT+ R8 R15 115K 59K A -5V R4 0.033UF 10.5K B B -7V SGND EN/UVLO EN/UVLO C11 1000PF RESET RESET SGND PGND PGND GND0 A A PROJECT TITLE: DRAWING TITLE: SIZE MAX17681B EVKIT DATE: HARDWARE NUMBER: B ENGINEER: 06/22/15 DRAWN BY: REV: TEMPLATE REV: 1.5 8 7 6 5 4 3 2 A SHEET 2 OF 2 1