MAX17574 5V Output Evaluation Kit General Description The MAX17574 5V output evaluation kit (EV kit) provides a proven design to evaluate the MAX17574 high-voltage, high-efficiency, synchronous step-down DC-DC converter. The EV kit is preset for 5V output at load currents up to 3A and features a 500kHz switching frequency for optimum efficiency and component size. The EV kit features adjustable input undervoltage lockout, adjustable soft-start, open-drain RESET signal, and external frequency synchronization. Ordering Information appears at end of data sheet. Evaluates: MAX17574 in 5V Output-Voltage Application Features ● Operates from a 6.5V to 60V Input Supply ● 5V Output Voltage ● Up to 3A Output Current ● 500kHz Switching Frequency ● Enable/UVLO Input, Resistor-Programmable UVLO Threshold ● Adjustable Soft-Start Time ● MODE/SYNC Pin to Select Among PWM, PFM, or DCM Modes ● Open-Drain RESET Output ● External Frequency Synchronization ● Overcurrent and Overtemperature Protection ● Proven PCB Layout ● Fully Assembled and Tested 19-8745; Rev 0; 12/16 MAX17574 5V Output Evaluation Kit Quick Start Recommended Equipment ● MAX17574 5V output EV kit ● 6.5V to 60V, 5A DC input power supply ● Load capable of sinking 3A ● Digital voltmeter (DVM) Procedure The EV kit is fully assembled and tested. Follow the steps below to verify the board operation. Caution: Do not turn on power supply until all connections are completed. 1) Set the power supply at a voltage between 6.5V and 60V. Disable the power supply. 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the nearest PGND PCB pad. Connect the positive terminal of the 3A load to the VOUT PCB pad and the negative terminal to the nearest PGND PCB pad. 3) Connect the DVM across the VOUT PCB pad and the nearest PGND PCB pad. 4) Verify that shunts are installed across pins 1-2 on jumper JU1 and pins 2-3 on jumper JU3 (see Table 1 for details). 5) Select the shunt position on jumper JU2 according to the intended mode of operation (see Table 2 for details). 6) Turn on the DC power supply. 7) Enable the load. Evaluates: MAX17574 in 5V Output-Voltage Application Detailed Description The MAX17574 5V output EV kit provides a proven design to evaluate the MAX17574 high-voltage, highefficiency, synchronous step-down DC-DC converter. The EV kit is preset for 5V output from 6.5V to 60V input at load currents up to 3A and features a 500kHz switching frequency for optimum efficiency and component size. The EV kit includes an EN/UVLO PCB pad and jumper JU1 to enable the output at a desired input voltage. The SYNC PCB pad and jumper JU3 allow an external clock to synchronize the device. Jumper JU2 allows the selection of a particular MODE/SYNC of operation based on light-load performance requirements. An additional RESET PCB pad is available for monitoring whether the converter output is in regulation. Soft-Start Input (SS) The device utilizes an adjustable soft-start function to limit inrush current during startup. The soft-start time is adjusted by the value of C8, the external capacitor from SS to GND. The selected output capacitance (CSEL) and the output voltage (VOUT) determine the minimum value of C8, as shown by the following equation: C8 ≥ 28 x 10-6 x CSEL x VOUT The soft-start time (tSS) is related to C8 by the following equation: tSS = C8/(5.55 x 10-6) For example, to program a 1ms soft-start time, C8 should be 5.6nF. 8) Verify that the DVM displays 5V. www.maximintegrated.com Maxim Integrated │ 2 MAX17574 5V Output Evaluation Kit Regulator Enable/Undervoltage-Lockout Level (EN/UVLO) The device offers an adjustable input undervoltagelockout level. For normal operation, a shunt should be installed across pins 1-2 on jumper JU1. To disable the output, install a shunt across pins 2-3 on JU1 and the EN/ UVLO pin is pulled to GND. See Table 1 for JU1 settings. Set the voltage at which the device turns on with the resistive voltage-divider R1/R2 connected from VIN_ to SGND. Connect the center node of the divider to EN/UVLO. Choose R1 to be 3.32MΩ and then calculate R2 as follows: R2 = R1× 1.215 (VINU − 1.215) Evaluates: MAX17574 in 5V Output-Voltage Application MODE Selection (MODE/SYNC) The device’s MODE/SYNC pin can be used to select among PWM, PFM, or DCM modes of operation. The logic state of the MODE/SYNC pin is latched when VCC and EN/UVLO voltages exceed the respective UVLO rising thresholds and all internal voltages are ready to allow LX switching. State changes on the MODE/SYNC pin are ignored during normal operation. Refer to the MAX17574 IC data sheet for more information on the PWM, PFM, and DCM modes of operation. Table 2 shows EV kit jumper settings that can be used to configure the desired mode of operation. External Clock Synchronization MODE/SYNC) where VINU is the voltage at which the device is required to turn on. Table 1. Regulator Enable (EN/UVLO) Description (JU1) SHUNT POSITION EN/UVLO PIN MAX17574_ OUTPUT 1-2* Connected to VIN Enabled Not installed Connected to the center node of resistor-divider R1 and R2 Enabled, UVLO level set through the R1 and R2 resistors 2-3 Connected to SGND Disabled The internal oscillator of the device can be synchronized to an external clock signal on the SYNC pin. The external synchronization clock frequency must be between 1.1fSW and 1.4fSW, where fSW is the frequency of operation set by R3. The minimum external clock high pulse width should be greater than 50ns and the minimum external clock low pulse width should be greater than 160ns. Table 2. MODE/SYNC Description (JU2) SHUNT POSITION MODE/SYNC PIN MAX17574_ MODE Not installed* Unconnected PFM mode of operation 2-3 Connected to SGND PWM mode of operation 1-2 Connected to VCC DCM mode of operation *Default position. *Default position. www.maximintegrated.com Maxim Integrated │ 3 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application EV Kit Test Report 5.01 5.00 VIN = 36V 5.2 VIN = 48V 5.15 VIN = 48V 5.1 4.99 VIN = 12V 5.05 5 4.98 4.95 4.97 VIN = 24V VIN = 12V 4.96 4.9 4.8 4.94 4.75 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Figure 1. MAX17574 5V Output Load and Line Regulation (PWM Mode) VIN = 24V VIN = 36V 4.85 4.95 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Figure 3. MAX17574 5V Output Load and Line Regulation (PFM Mode) 100 100 TOC04 TOC03 90 95 90 70 VIN = 24V 60 VIN = 36V VIN = 48V EFFICIENCY (%) 80 VIN = 12V 50 85 80 VIN = 48V 75 70 40 30 TOC02 5.25 TOC01 5.02 MODE = SGND 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Figure 2. MAX17574 5V Output Efficiency (PWM Mode) www.maximintegrated.com VIN = 12V 65 60 VIN = 24V VIN = 36V MODE = OPEN 0.0 0.1 1.0 3.0 Figure 4. MAX17574 5V Output Efficiency (PFM Mode) Maxim Integrated │ 4 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application EV Kit Test Report (continued) MAX17574, 5V OUTPUT, 3A LOAD CURRENT, BODE PLOT 100 VIN = 48V VIN= 24V PHASE VIN = 12V 70 GAIN GAIN (dB) 60 50 CROSSOVER FREQUENCY = 52.4kHz, PHASE MARGIN = 65.4° 40 30 MODE = VCC 0.0 0.1 PHASE (°) 80 TOC06 TOC05 VIN = 36V 90 1.0 FREQUENCY (Hz) Figure 5. MAX17574 5V Output Efficiency (DCM Mode) MAX17574, 5V OUTPUT, PWM MODE, (LOAD CURRENT STEPPED FROM NO LOAD TO 1.5A) Figure 6. MAX17574 5V Output Full Load Bode Plot (VIN = 24V) MAX17574, 5V OUTPUT, PFM MODE, (LOAD CURRENT STEPPED FROM 5mA TO 1.5A) 100mV/div ILX 1A/div 100μS/div Figure 7. MAX17574 5V Output, No Load to 1A Load Transient (PWM Mode) www.maximintegrated.com TOC08 TOC07 VOUT AC VOUT AC 100mV/div ILX 1A/div 2mS/div Figure 8. MAX17574 5V Output, 5mA to 1A Load Transient (PFM Mode) Maxim Integrated │ 5 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application EV Kit Test Report (continued) MAX17574, 5V OUTPUT, DCM MODE (LOAD CURRENT STEPPED FROM 50mA TO 1.5A) MAX17574, 3.3V OUTPUT, PWM MODE, (LOAD CURRENT STEPPED FROM 1.5A TO 3A) TOC10 TOC09 VOUT (AC) IOUT 100mV/div MODE = VCC 1A/div VOUT AC 100mV/div ILX 1A/div 100μS/div 200μs/div Figure 9. MAX17574 5V Output, 50mA to 1A Load Transient (DCM Mode) Figure 10. MAX17574 5V Output, 1A to 2A Load Transient Component Suppliers SUPPLIER WEBSITE Coilcraft, Inc. www.coilcraft.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com Taiyo Yuden www.t-yuden.com TDK Corp. www.tdk.com Note: Indicate that you are using the MAX17574 when contacting these component suppliers. Ordering Information PART TYPE MAX17574EVKITB# EV Kit #Denotes RoHS compliant. www.maximintegrated.com Maxim Integrated │ 6 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application MAX17574 5V EV System Bill of Materials SERIAL NO. 1 DESCRIPTION 2.2μF ±10%, 100V X7R ceramic capacitor (1210) QUANTITY DESIGNATOR PART NUMBER 2 C1,C2 MURATA GRM32ER72A225KA35 2 22μF ±10%, 10V X7R ceramic capacitor (1210) 2 C3,C4 MURATA GRM32ER71A226K 3 0.1μF ±10%, 50V X7R ceramic capacitor (0402) 2 C5,C9 MURATA GRM155R71H104KE14 MURATA GRM188R71A225KE15 4 2.2μF ±10%, 10V X7R ceramic capacitor (0603) 1 C6 5 47uF, 80V electrolytic capacitor (6.3mm. Dia.) 1 C7 PANASONIC EEE-FK1K470P 6 0.022μF ±10%, 50V X7R ceramic capacitor (0402) 1 C8 MURATA GRM155R71H223KA12 7 0.1μF ±10%, 100V X7R ceramic capacitor (0603) 1 C11 MURATA GRM188R72A104KA35 8 2-pin header (36-pin header 0.1” centers ) 2 JU1, JU2 Sullins: PEC03SAAN Coilcraft XAL8080-103ME 9 10uH Inductor (4mm x 4mm x 3mm) 1 L1 10 3.3M ohm ±1%, resistor (0603) 1 R1 Any 11 604k ohm ±1%, resistor (0603) 1 R2 Any 12 10k ohm ±1%, resistor (0402) 1 R4 Any 13 4.7 ohm ±1%, resistor (0402) 1 R5 Any 14 105k ohm ±1%, resistor (0402) 1 R6 Any 15 22.6k ohm ±1%, resistor (0402) 1 R7 Any 16 Buck Converter MAX17574ATG+ 1 U1 17 OPEN 1 C10 MAX17574ATG+ 18 OPEN 1 R3 19 Shunt 2 See the jumper table SULLINS STC02SYAN 9020 BUSS WEICO WIRE 20 Test Loops 8 VIN, SGND, VOUT, PGND1, PGND2, RESET/, EN/UVLO, MODE/SYNC 21 MEDIUM BROWN 9 3/8” X 7 1/4” X 2 1/2 1 Pack-out 22 WEB instructions for Maxim Data Sheet 1 Pack-out 23 Label 1 Pack-out Pack-out 24 BAG; STATIC SHIELD 5X8;W/ESD LOGO 1 25 FOAM, ANTI-STATIC PE 12”x12”X5MM 1 Pack-out 26 Rubber bumpers, 3M SJ-5003 4 Pack-out Jumper Table JUMPER SHUNT POSITION JU1 1-2 JU2 2-3 for PWM and 1-2 for PFM mode www.maximintegrated.com Maxim Integrated │ 7 SGND RESET/ MODE/SYNC MODE/SYNC JU2 1 VCC VCC 2 10K R4 2.2UF C6 OPEN R3 MAX17574 U1 NC SS PGND PGND PGND NC RESET\ SGND VCC 3.3M R1 C8 SGND PGND NC FB CF LX LX LX BST 17 18 13 1 23 24 22 0.1UF C9 EP EXTVCC EN/UVLO VIN VIN VIN VIN MODE/SYNC RT 0.022UF 14 4 8 21 15 12 19 604K R2 2 VCC 2 10 3 EN/UVLO 5 11 3 1 6 JU1 7 25 EN/UVLO 16 9 20 4.7 R5 OPEN C10 1 0.1UF C5 L1 10UH 0.1UF C11 2 2.2UF C2 22UF C3 22UF C4 VOUT 2.2UF C1 VIN 1 22.6K R7 105K R6 47UF C7 + www.maximintegrated.com 2 3 5V,3A PGND VOUT PGND VIN MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application MAX17574 5V EV System Schematic Maxim Integrated │ 8 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application MAX17574 5V EV System PCB Layout MAX17574 5V EV Kit—Top Silkscreen MAX17574 5V EV Kit—Top MAX17574 5V EV Kit—Layer 2 GND www.maximintegrated.com Maxim Integrated │ 9 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application MAX17574 EV System PCB Layout (continued) MAX17574 5V EV Kit—Layer 3 GND www.maximintegrated.com MAX17574 5V EV Kit—Bottom Maxim Integrated │ 10 MAX17574 5V Output Evaluation Kit Evaluates: MAX17574 in 5V Output-Voltage Application Revision History REVISION NUMBER REVISION DATE 0 12/16 DESCRIPTION Initial release PAGES CHANGED — 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. │ 11