Evaluates: MAX17545 in MAX17545 3.3V Output Evaluation Kit 3.3V Output-Voltage Application General Description Features The MAX17545 3.3V output evaluation kit (EV kit) provides Operates from a 4.5V to 42V Input Supply a proven design to evaluate the MAX17545 high-voltage, 3.3V Output Voltage high-efficiency, synchronous step-down DC-DC convert- Up to 1.7A Output Current er. The EV kit is preset for 3.3V output at load currents 450kHz Switching Frequency up to 1.7A and features a 450kHz switching frequency for optimum efficiency and component size. The EV kit Enable/UVLO Input, Resistor-Programmable UVLO features adjustable input undervoltage lockout, adjust- Threshold able soft-start, open-drain RESET signal, and external Adjustable Soft-Start Time frequency synchronization. MODE Pin to Select Among PWM, PFM, or DCM Modes Open-Drain RESET Output External Frequency Synchronization Ordering Information appears at end of data sheet. Overcurrent and Overtemperature Protection Proven PCB Layout Fully Assembled and Tested Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION 2.2F 10%, 50V X7R ceramic 6.8H inductor C1 1 capacitor (1210) L1 1 Coilcraft XAL6060-682ME TDK C3225X7R1H225K Sumida 0420CDMCDS-6R8MC R1 1 3.32M 1% resistor (0402) 2.2F 10%, 10V X7R ceramic C2 1 capacitor (0603) R2 1 1M 1% resistor (0402) Murata GRM188R71A225K R3 1 127k 1% resistor (0402) R4 1 47.5k 1% resistor (0402) 5600pF 10%, 25V X7R ceramic C3 1 capacitor (0402) R5 0 45.3k 1% resistor (0402) Murata GRM155R71E562K R6 1 10k 1% resistor (0402) 47F 10%, 10V X7R ceramic TP1, TP2 2 Test pads C4 1 capacitor (1210) Buck converter (20 TQFN-EP*) U1 1 Murata GRM32ER71A476K Maxim MAX17545ATP+ 0.1F 10%, 16V X7R ceramic 3 Shunts (JU1JU3) C5 1 capacitor (0402) PCB: MAX17545 - 3.3V OUTPUT Murata GRM155R71C104K 1 EVKIT Not installed, ceramic capacitor C6 0 *EP = Exposed pad. (0402) Note: C7, R1, and R2 are optional components R1 and R2 are 47F, 50V aluminum electrolytic not needed if the EN/UVLO pin is permanently connected to C7 1 capacitor (D = 10mm) VIN. The electrolytic capacitor (C7) is required only when the Panasonic EEEFK1H470XP VIN power supply is situated far from the MAX17545-based circuit. When R5 is open, the device switches at 500kHz JU1JU3 3 3-pin headers switching frequency. The XAL6060 inductor has been used to prepare the EV kit test report. 19-7351 Rev 0 10/14Evaluates: MAX17545 in MAX17545 3.3V Output Evaluation Kit 3.3V Output-Voltage Application Component Suppliers SUPPLIER PHONE WEBSITE Coilcraft, Inc. 847-639-6400 www.coilcraft.com Murata Americas 800-241-6574 www.murataamericas.com Panasonic Corp. 800-344-2112 www.panasonic.com Sumida Corp. 408-321-9660 www.sumida.com TDK Corp. 516-535-2600 www.tdk.com Note: Indicate that you are using the MAX17545 when contacting these component suppliers. Quick Start Detailed Description The MAX17545 3.3V output EV kit provides a proven Recommended Equipment design to evaluate the MAX17545 high-voltage, high- MAX17545 3.3V output EV kit efficiency, synchronous step-down DC-DC converter. The 4.5V to 42V, 4A DC input power supply EV kit is preset for 3.3V output from 4.5V to 42V input at load currents up to 1.7A and features a 450kHz switching Load capable of sinking 2A frequency for optimum efficiency and component size. Digital voltmeter (DVM) The EV kit includes an EN/UVLO PCB pad and jumper Procedure JU1 to enable the output at a desired input voltage. The The EV kit is fully assembled and tested. Follow the steps SYNC PCB pad and jumper JU3 allow an external clock below to verify the board operation. Caution: Do not turn to synchronize the device. Jumper JU2 allows the selec- on power supply until all connections are completed. tion of a particular mode of operation based on light-load performance requirements. An additional RESET PCB 1) Set the power supply at a voltage between 5V and pad is available for monitoring whether the converter out- 42V. Disable the power supply. put is in regulation. 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the Soft-Start Input (SS) nearest PGND PCB pad. Connect the positive termi- The device utilizes an adjustable soft-start function to nal of the 1.7A load to the VOUT PCB pad and the limit inrush current during startup. The soft-start time is negative terminal to the nearest PGND PCB pad. adjusted by the value of C3, the external capacitor from 3) Connect the DVM across the VOUT PCB pad and SS to GND. The selected output capacitance (C ) and SEL the output voltage (V ) determine the minimum value the nearest PGND PCB pad. OUT of C3, as shown by the following equation: 4) Verify that shunts are installed across pins 1-2 on -6 jumper JU1 and pins 2-3 on jumper JU3 (see Tables 1 C3 28 x 10 x C x V SEL OUT and 3 for details). The soft-start time (t ) is related to C3 by the following SS equation: 5) Select the shunt position on jumper JU2 according to the intended mode of operation (see Table 2 for -6 t = C3/(5.55 x 10 ) SS details). For example, to program a 1ms soft-start time, C3 should 6) Turn on the DC power supply. be 5.6nF. 7) Enable the load. 8) Verify that the DVM displays 3.3V. Maxim Integrated 2 www.maximintegrated.com