Click here for production status of specific part numbers. Evaluates: MAX17546 MAX17546EVKITB Evaluation Kit 5V Output-Voltage Application General Description Quick Start The MAX17546 5V output evaluation kit (EV kit) provides Recommended Equipment a proven design to evaluate the MAX17546 high-voltage, MAX17546EVKITB high-efficiency, synchronous step-down DC-DC converter. 6.5V to 42V, 10A DC input power supply The EV kit is preset for a 5V output at load currents up to 5A and features a 450kHz switching frequency Load capable of sinking 5A for optimum efficiency and component size. The EV kit Digital voltmeter (DVM) features adjustable input, undervoltage lockout, adjust- able soft-start, open-drain RESET signal, and external Procedure frequency synchronization. The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn Features on power supply until all connections are completed. Operates from a 6.5V to 42V Input Supply 1) Set the power supply at a voltage between 6.5V and 5V Output Voltage 42V. Disable the power supply. Up to 5A Output Current 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the 450kHz Switching Frequency nearest PGND PCB pad. Connect the positive terminal Enable/UVLO Input, Resistor-Programmable UVLO of the 5A load to the VOUT PCB pad and the negative Threshold terminal to the nearest PGND PCB pad. Adjustable Soft-Start Time 3) Connect the DVM across the VOUT PCB pad and MODE Pin to Select Among PWM, PFM, or DCM the nearest PGND PCB pad. Modes 4) Verify that the shunt is installed across pins 1-2 on Open-Drain RESET Output jumper JU1 (see Table 1 for details). External Frequency Synchronization 5) Select the shunt position on JU2 based on the intended mode of operation (see Table 2 for details). Overcurrent and Overtemperature Protection 6) Turn on the DC power supply. Proven PCB Layout 7) Enable the load. Fully Assembled and Tested 8) Verify that the DVM displays 5V. Ordering Information appears at end of data sheet. 19-7695 Rev 2 4/18Evaluates: MAX17546 MAX17546EVKITB Evaluation Kit 5V Output-Voltage Application installed across pins 1-2 on JU1. To disable the output, Detailed Description install a shunt across pins 2-3 on JU1 and pull the EN/ The EV kit provides a proven design to evaluate the UVLO pin to GND. See Table 1 for JU1 settings. MAX17546 high-voltage, high-efficiency, synchronous step-down DC-DC converter. The EV kit is preset for a 5V Set the voltage at which the device turns on with the resistive voltage-divider R1/R2 connected from VIN to output from a 6.5V to 42V input at load currents up to 5A and features a 450kHz switching frequency for optimum SGND. Connect the center node of the divider to EN/ UVLO. Choose R1 to be 3.32M and then calculate R2 efficiency and component size. as follows: The EV kit includes an EN/UVLO PCB pad and JU1 to enable the output at a desired input voltage. The SYNC R1 x 1.215 R2 = VINU - 1.215 PCB pad allow an external clock to synchronize the device. JU2 allows the selection of a particular mode of where VINU is the voltage at which the device is required operation based on light-load performance requirements. to turn on. An additional RESET PCB pad is available for monitoring when the converter output is in regulation. Mode/SYNC Selection (MODE) The devices MODE pin can be used to select among the Soft-Start Input (SS) PWM, PFM, or DCM modes of operation. The logic state of the The device utilizes an adjustable soft-start function to MODE pin is latched when the V and EN/UVLO voltages CC limit inrush current during startup. The soft-start time is exceed the respective UVLO rising thresholds and all internal adjusted by the value of the external capacitor from SS to voltages are ready to allow LX switching. State changes on the GND (C7). The selected output capacitance (C ) and SEL MODE pin are ignored during normal operation. Refer to the output voltage (V ) determine the minimum value of OUT MAX17546 IC data sheet for more information on the PWM, C7, as shown by the following equation: PFM, and DCM modes of operation. -6 C7 28 x 10 x C x V SEL OUT Table 2 lists JU2 jumper settings that can be used to The soft-start time (t ) is related to C7 by the following SS configure the desired mode of operation. The internal equation: oscillator of the device can be synchronized to an external -6 t = C7/(5.55 x 10 ) clock signal on the SYNC pin. The external synchronization SS clock frequency must be between 1.1f and 1.4f , SW SW For example, to program a 2.2ms soft-start time, C7 where f is the frequency of operation set by R5. The SW should be 12nF. minimum external clock high pulse width should be greater Regulator Enable/Undervoltage-Lockout Level than 50ns, while the minimum external clock low pulse width (EN/UVLO) should be greater than 160ns. The device offers an adjustable-input, undervoltage- lockout level. For normal operation, a shunt should be Table 1. Regulator Enable (EN/UVLO) Description (JU1) SHUNT POSITION EN/UVLO PIN MAX17546 OUTPUT 1-2* Connected to VIN Enabled Connected to the center node of Enabled, UVLO level set through the Not installed resistor-divider R1 and R2 R1 and R2 resistors 2-3 Connected to SGND Disabled *Default position. Table 2. MODE Description (JU2) SHUNT POSITION MODE PIN MAX17546 MODE Not installed* Unconnected PFM mode of operation 1-2 Connected to SGND PWM mode of operation 2-3 Connected to VCC DCM mode of operation *Default position. Maxim Integrated 2 www.maximintegrated.com