Click here to ask about production status of specific part numbers. MAX17576EVKITB Evaluation Kit Evaluates: MAX17576 5V Output-Voltage Application General Description Quick Start The MAX17576EVKITB evaluation kit (EV kit) provides Recommended Equipment a proven design to evaluate the MAX17576 high-voltage, MAX17576EVKITB t high-efficiency, synchronous step-down DC-DC convert- 6.5V to 60V, 5A DC input power supply er. The EV kit is preset for 5V output at load currents up to 4A and features a 350kHz switching frequency for Load capable of sinking 4A optimum efficiency and component size. The EV kit Two digital voltmeters (DVM) features adjustable input undervoltage lockout, adjustable soft-start, open-drain RESET signal, and external Equipment Setup and Test Procedure frequency synchronization. The EV kit also provides a The EV kit is fully assembled and tested. Follow good layout example, which is optimized for conducted, the steps below to verify the board operation. radiated EMI and thermal performance. For more details Caution: Do not turn on power supply until all con- about the IC benefits and features, refer to the MAX17576 nections are completed. IC data sheet. 1) Set the power supply at a voltage of 6V. Then, dis- able the power supply. Features 2) Connect the positive terminal of the power supply to Operates from a 6.5V to 60V Input Supply the VIN PCB pad and the negative terminal to the 5V Output Voltage nearest PGND PCB pad. Connect the positive ter- Up to 4A Output Current minal of the 4A load to the VOUT PCB pad and the negative terminal to the nearest PGND PCB pad. 350kHz Switching Frequency 3) Connect one DVM across the VOUT PCB pad and Enable/UVLO Input, Resistor-Programmable UVLO the nearest PGND PCB pad, and the other DVM Threshold across the RESET PCB pad and SGND PCB pad. Adjustable Soft-Start Time 4) Verify that shunts are not installed across any pins MODE/SYNC Pin to Select Either PWM, PFM, or on jumper JU1 (see Table 1 for details). DCM Mode 5) Turn on the DC power supply. Open-Drain RESET Output 6) Enable the load. External Frequency Synchronization 7) Increase the input voltage to 6.4V, which is above Overcurrent and Overtemperature Protection the EN/UVLO rising threshold. Proven PCB Layout 8) Verify that the DVM across the VOUT PCB pad and Fully Assembled and Tested the nearest PGND PCB pad displays 5V. CISPR-22 Class B Compliant 9) Verify that the DVM across the RESET PCB pad and the nearest SGND PCB pad displays 5V. 10) The power supply voltage can be set at any voltage Ordering Information appears at end of data sheet. between 6.5V and 60V. 11) Reduce the input voltage to 5V, which is below the EN/UVLO falling threshold. 12) Verify that both the DVMs displays 0V. 13) Disable the input power supply. 319-100291 Rev 1 9/20MAX17576EVKITB Evaluation Kit Evaluates: MAX17576 5V Output-Voltage Application across pins 23 on JU1. See Table 1 for JU1 settings. The .Detailed Description EN/UVLO PCB pad on the EV kit supports external Enable/ The EV kit is designed to deliver 5V output at a load cur- Disable control of the device. Leave JU1 open when exter- rent up to 4A from a 6.5V to 60V input supply. The EV kit nal Enable/Disable control is desired. A potential divider is programmed at 350kHz switching frequency for opti- formed by R1 and R2 sets the input voltage (V ) above INU mum efficiency and component size. which the converter is enabled when JU1 is left open. The EV kit includes an EN/UVLO PCB pad and jumper Choose R1 to be 3.32M (max) then calculate R2 as JU1 to enable the output at a desired input voltage. The follows: MODE/SYNC PCB pad allows an external clock to syn- chronize the device. Jumper JU2 allows the selection of a 1.215 R1 R2 = particular MODE/SYNC of operation based on light-load (V 1.215) INU performance requirements. An additional RESET PCB pad is available for monitoring whether the converter out- where, V is the voltage at which the device is required INU put is in regulation or not. to turn on, and R1 and R2 are in k. For more details about setting the undervoltage lockout level, refer to the Soft-Start Input (SS) MAX17576 data sheet. The EV kit offers an adjustable soft-start function to limit inrush current during startup. The soft-start time is MODE Selection (MODE/SYNC) adjusted by the value of the external soft-start capacitor The EV kit provides a jumper (JU2) that allows the MAX17576 (C5) connected between SS and SGND. The selected to operate in PWM, PFM, and DCM modes. Refer to the output capacitance (C ) and the output voltage (V ) SEL OUT MAX17576 data sheet for more details on the modes of determine the minimum value of C5, as shown by the fol- operation. Table 2 shows the mode selection (JU2) settings lowing equation: that can be used to configure the desired mode of operation. -6 C5 28 x 10 x C x V SEL OUT External Clock Synchronization (MODE/SYNC) The soft-start time (t ) is related to C5 by the following SS The EV kit provides a MODE/SYNC PCB pad to synchro- equation: nize the MAX17576 to an optional external clock. Leave -6 t = C5/(5.55 x 10 ) SS the jumper (JU2) open when external clock signals are applied. In the presence of a valid external clock for syn- For example, to program a 1ms soft-start time, C5 should chronization, the MAX17576 operates in PWM mode only. be 5.6nF. For more details about external clock synchronization, Enable/Undervoltage-Lockout Level (EN/UVLO) refer to the MAX17576 data sheet. Programming Active-Low, Open-Drain Reset Output (RESET) The MAX17576 offers an Enable and adjustable input The EV kit provides a RESET PCB pad to monitor the sta- undervoltage lockout feature. In this EV kit, for normal opera- tus of the converter. RESET goes high when VOUT rises tion, leave the EN/UVLO jumper (JU1) open. When JU1 is above 95% (typ) of its nominal regulated output voltage. left open, the MAX17576 is enabled after the input voltage RESET goes low when VOUT falls below 92% (typ) of its rises above 6.4V. To disable the MAX17576, install a jumper nominal regulated voltage. Table 1. Converter EN/UVLO Jumper (JU1) Table 2. MODE Selection Jumper (JU2) Settings Settings SHUNT SHUNT MODE/SYNC EN/UVLO PIN MAX17576 OUTPUT MAX17576 MODE POSITION POSITION PIN 1-2 Connected to VIN Enabled PFM mode of Not installed Unconnected operation Connected to the Enabled, UVLO level Not center node of Connected to PWM mode of set through the R1 and 2-3* installed* resistor-divider R1 SGND operation R2 resistors and R2 Connected to DCM mode of 1-2 V operation 2-3 Connected to SGND Disabled CC *Default position. *Default position. Maxim Integrated 2 www.maximintegrated.com