Evaluates: MAX17682 for Isolated +12V Output Configuration. MAX17682 Evaluation Kit. General Description. Quick Start. Features. Recommended Equipment

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1 General Description The MAX7 EV kit is a fully assembled and tested circuit board that demonstrates the performance of the MAX7 high-efficiency, iso-buck DC-DC Converter. The EV kit operates over a wide input-voltage range of V to 4V and uses primary-side feedback to regulate the output voltage. The EV kit has isolated output, programmed to +V at 750mA, with 0% output voltage regulation. The EV kit comes installed with the MAX7 in a 0-pin (4mm x 4mm) TDFN package. Features V to 4V Input Voltage Range +V, 750mA Continuous Current Input 00kHz Switching Frequency 9% Peak Efficiency Overcurrent Protection No Optocoupler Delivers up to 0W Output Power Overtemperature Protection Proven PCB layout Ordering Information appears at end of data sheet. Quick Start Recommended Equipment One 5V - 0V DC, A Power Supply One resistive load 750mA sink capacity Two Digital Multimeters (DMM) Caution: Do not turn on the power supply until all connections are completed. Procedure The EV kit comes with the default secondary output programmed to +V. ) Verify that the J is open ) Set the power supply output to 4V. Disable the power supply ) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the nearest PCB pad. Connect a 750mA resistive load across the +V PCB pad and the GND0 PCB pad. 4) Connect a DMM configured in voltmeter mode across the +V PCB pad and the nearest GND0 PCB pad. 5) Enable the input power supply. ) Verify that output voltage is at +V (with allowable tolerance of 0%) with respect to GND0. 7) If required, vary the input voltage from V to 4V, and the load current from 0mA to 750mA and verify that output voltage is at +V (with allowable tolerance of 0%) ; Rev 0; /7

2 Detailed Description The MAX7EVKITA evaluation kit (EV kit) is a fully assembled and tested circuit board that demonstrates the performance of the MAX7 high-efficiency, isobuck, DC-DC converter designed to provide an isolated power up to 0W. The EV kit generates +V, 750mA voltages from a V to 4V input supply. The EV kit features a forced-pwm control scheme that provides constant switching-frequency of 00 khz operation at all load and line conditions. The EV Kit includes an PCB pad to monitor and program the pin of the MAX7. The VPRI PCB pad helps measure the regulated primary output voltage (V PRI ). An additional RESETB PCB pad is available for monitoring the health of primary output voltage (V PRI ). RESETB pulls low if FB voltage drops below 9%(typ) of its set value and RESETB goes high impedance 04 clock cycles after FB voltage rises above 95% 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 opto-coupler. The detailed procedure for setting the soft-start time, ENABLE/UVLO divider, primary output voltage (V PRI ) 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 MAX7 IC data sheet. Enable Control (J) The pin on the device serves as an on/ off control while also allowing the user to program the input undervoltage lockout (UVLO) threshold. Jumper J configures the EV kit s output for turn-on/turn-off control. Install a shunt across jumper J pins - to disable VOUT. See Table for proper J jumper configurations. Table. Enable Control () (J) Jumper Settings SHUNT POSITION PIN V OUT OUTPUT J *Default position. - Connected to V IN Always Enabled - Connected to GND Always Disabled Open* Connected to midpoint of R, R resistor-divider Enabled at V IN 5V Note : The secondary output diodes D is rated to carry short-circuit current only for few hundredths of a millisecond and is not rated to carry the continuous short-circuit current. Note : The iso-buck converter typically needs 0% minimum load to regulate the output voltage. In this design when the +V rail is healthy, U sinks the minimum load current required to regulate the output voltages within ±0% regulation. Maxim Integrated

3 EV Kit Performance Report EFFICIENCY vs. LOAD CURRENT toc0 LOAD TRANSIENT RESPONSE (LOAD CURRENT STEPPED FROM 75mA to 700mA) toc EFFICIENCY (%) V IN = V V IN = 4V V IN = 4V V OUT (AC) 500mV/div I OUT 500mA/div LOAD CURRENT (ma) 400µs/div OUTPUT VOLTAGE vs. LOAD CURRENT +V output toc0 FULL-LOAD SWITCHING WAVEFORMS toc04 OUTPUT VOLTAGE (V) 4 0 V IN =V V IN =4V LOAD CURRENT (ma) V IN =V LX V OUT (AC) I PRI I SEC µs/div 0V/div 00mV/div A/div A/div Maxim Integrated

4 Component Suppliers SUPPLIER WEBSITE Wurth Electronik Murata Americas Panasonic Corp. Note: Indicate that you are using the MAX7 when contacting these component suppliers. MAX7 EV Kit Bill of Materials S NO Designation Qty Description Manu Part # Manu Part # Manu Part # C.µF±0%, 00V,X7R Ceramic capacitor (0) Murata GRMER7A5KA5 TDK CGANX7RA5K0 C 47µF, 0%, 0V, ALUMINUM ELECTROLYTIC CAPACITOR.0*.0mm, Panasonic EEE-FKK470P C 0.µF±0%,00V, X7R ceramic capacitor (00) Murata GRMR7A04KA5 TDK CC00KRX7R0BB04 4 C4,C 0µF±0%,V, X7R ceramic capacitor (0) Murata GRMDR7C0KA0 TDK C5X7RC0K 5 C5, C µf±0%,0v, X7R ceramic capacitor (0) Murata GRMER7AME0 C7 0.0µF±5%,5V,X7R ceramic capacitor (040) Murata GRM55R7EKA 7 C 00pF±0%,50V, X7R ceramic capacitor (040) Murata GRM55R7HJA0 C9 0.05uF±0%, V, X7R ceramic capacitor (040) Murata GRM55R7C5KA0 KEMET C040C5K4RAC 9 C0 0.uF±0%, V, X7R ceramic capacitor (040) Murata GRM55RC04KA 0 C.uF±0%,0V, X7R ceramic capacitor (00) Murata GRMR7A5KE5 SAMSUNG CL0B5KPNNN C 700pF±0%, 000V, X7R ceramic capacitor () AVX HC7KAZA D Diode, 50V/A, SMA Diode Inc. SBRU50SA JU,JU -pin headers SULLINS ELECTRONICS CORP PEC0SAAN 4 R.M Ohm±% resistor (00) VISHAY DALE CRCW00M0FK 5 R 7K Ohm±% resistor (00) VISHAY DALE CRCW007KFK R 7.7K Ohm±% resistor (040) VISHAY DALE CRCW0407K7FK KEMET C0C0K4RAC 7 R4,R,R0 0kΩ ±% resistor (040) VISHAY DALE CRCW0400K0FK R5.4kΩ ±% resistor (040) VISHAY DALE CRCW040K4FK 9 R Ω ±% resistor (00) VISHAY DALE RCS00R0FK 0 R9 40.kΩ ±% resistor (040) VISHAY DALE CRCW04040KFK R7 05kΩ ±% resistor (040) VISHAY DALE CRCW04005KFK T EVKIT PART-TRANSFORMER; SMT;.7: WURTH ELECTRONICS INC U MAX7 TQFN0 4*4mm Iso buck DC-DC converter MAX7 YAGEO PHICOMP RC040FR-070K 4 U Shunt regulator SOT5 5 SU,SU See Jumper Table VIN, GND0,, SGND, SYNC, VOUT, VPRI,, RESETB, ST MICROELECTRONICS TL4AIYDT SULLINS ELECTRONICS CORP - STC0SYAN 0 Test Loops WEICO WIRE BUSS Maxim Integrated 4

5 SGND V TO 4V +V,0mA GND0 +V,750mA U R7 R JU R R C 47UF 4 5 R 7.7K R4 0K C5 UF T C UF 7 D C4 0UF VPRI C 0UF C R9 40.K R0 0K R VOUT GND0 + SGND RESETB C C 00PF R5.4K C9 0.05UF C7 0.0UF C 0.UF C.UF C0 0.UF VIN 7 4 SYNC JU RESETB 05K VCC.UF 7K.M U MAX7 RESETB 0K VCC 700PF TL4AIYDT ANODE REF ANODE CATHODE ANODE ANODE NC NC RT SYNC NC VCC SGND BST LX LX LX RESETB MAX7 EV Kit Schematics EP VIN VIN VIN FB COMP SS Maxim Integrated 5

6 MAX7 EV Kit PCB Layout Diagrams MAX7 EV Kit Top Silkscreen MAX7 EV Kit Top Maxim Integrated

7 MAX7 EV PCB Layout Diagrams (continued) MAX7 EV Kit Level SGND MAX7 EV Kit Level SGND Maxim Integrated 7

8 MAX7 EV Kit PCB Layout Diagrams (continued) MAX7EV Bottom Ordering Information PART MAX7EVKIT# #Denotes RoHS compliant. TYPE EVKIT Maxim Integrated

9 Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 0 /7 Initial release For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim Integrated s website at. 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. 07 Maxim Integrated Products, Inc. 9