Click here for production status of specific part numbers. MAX17575EVKITBE Evaluation Kit Evaluates: MAX17575 in 5V Output-Voltage Application General Description Quick Start The MAX17575EVKITBE (EV kit) provides a proven Recommended Equipment design to evaluate the MAX17575 high-voltage, high-effi- MAX17575EVKITBE ciency, synchronous step-down DC-DC converter. The EV 6.5V to 60V, 2A DC input power supply kit is preset for 5V output at load currents up to 1.5A and features a 500kHz switching frequency for optimum efficiency Load capable of sinking 1.5A and component size. The EV kit features adjustable input Digital voltmeter (DVM) undervoltage-lockout, adjustable soft-start, open-drain RESET signal, and external clock synchronization. The EV Equipment Setup and Test Procedure kit also provides a good layout example, which is optimized The EV kit is fully assembled and tested. Follow the steps for conducted, radiated EMI, and thermal performance. For below to verify the board operation. more details about the IC benefits and features, refer to the Caution: Do not turn on power supply until all con- MAX17575 data sheet. nections are completed. 1) Set the power supply at a voltage between 6.5V and Features 60V. Disable the power supply. Operates From a 6.5V to 60V Input Supply 2) Connect the positive terminal of the power supply Programmed 5V Output Voltage, 1.5A Load Current to the V PCB pad and the negative terminal to the IN 500kHz Switching Frequency nearest PGND PCB pad. Connect the positive terminal Enable/UVLO Input, Resistor-Programmable UVLO of the 1.5A load to the V PCB pad and the negative OUT Threshold terminal to the nearest PGND PCB pad. Adjustable Soft-Start Time 3) Connect the DVM across the V PCB pad and OUT Open-Drain RESET Output the nearest PGND PCB pad. External Clock Synchronization 4) Verify that shunts are installed across pins 1-2 on Overcurrent and Overtemperature Protection jumper JU1 (see Table 1 for details). Proven PCB Layout 5) Turn on the DC power supply. Fully Assembled and Tested 6) Enable the load. Complies with CISPR22(EN55022) Class B Conducted and Radiated Emissions 7) Verify that the DVM displays 5V Ordering Information appears at end of data sheet. 319-100346 Rev 0 4/19MAX17575EVKITBE Evaluation Kit Evaluates: MAX17575 in 5V Output-Voltage Application input voltage rises above 6.4V. To disable the MAX17575, Detailed Description of Hardware install a jumper across pins 23 on JU1. See Table 1 The MAX17575EVKITBE provides a proven design to for JU1 settings. The EN/UVLO PCB pad on the EV kit evaluate the MAX17575 high-voltage, high efficiency, supports external Enable/Disable control of the device. synchronous step-down DC-DC converter. The EV kit Leave JU1 open when external Enable/Disable control is preset for 5V output from 6.5V to 60V input at load is desired. A potential divider formed by R1 and R2 sets currents up to 1.5A and features a 500kHz switching the input voltage (VINU) above which the converter is frequency for optimum efficiency and component size. enabled when JU1 is left open. The EV kit includes an EN/UVLO PCB pad and jumper Choose R1 to be 3.3M (max), and then calculate R2 as JU1 to enable the output at a desired input voltage. An additional RESET PCB pad is available for monitoring follows: whether the converter output is in regulation. R 1.215 1 R = 2 Soft-Start Capacitor Selection (V 1.215) INU The EV kit offers an adjustable soft-start operation to where, V is the voltage at which the device is required INU reduce inrush current. The soft-start time is adjusted by to turn on, and R1 and R2 are in k, the value of external soft-start capacitor (C5) connected between SS and SGND. The selected output capacitance For more details about setting the undervoltage lockout (C ) and the output voltage (V ) determine the mini- level, refer to the MAX17575 data sheet. SEL OUT mum required soft-start capacitor as follows: Active-Low, Open-Drain Reset Output (RE- 6 SET) C 56 10 C V SS SEL OUT The EV kit provides a RESET PCB pad to monitor the sta- The soft-start time (t ) is related to the capacitor SS tus of the converter. RESET goes high when VOUT rises connected at SS (C ) by the following equation: SS above 95% (typ) of its nominal regulated output voltage. RESET goes low when VOUT falls below 92% (typ) of its C SS nominal regulated voltage. t = SS 6 5.55 10 Hot Plug-In and Long Input Cables For example, to program a 2ms soft-start time, a 12nF The MAX17575EVKITBE PCB layout provides an option- capacitor should be connected from the SS pin to GND. al electrolytic capacitor (CIN4 = 33F/80V). This capacitor limits the peak voltage at the input of the MAX17575 when Enable/Undervoltage-Lockout (EN/UVLO) the DC input source is Hot-Plugged to the EV kit input Programming terminals with long input cables. The equivalent series The MAX17575 offers an Enable and adjustable input resistance (ESR) of the electrolytic capacitor dampens undervoltage lockout feature. In this EV kit, for normal the oscillations caused by interaction of the inductance operation, leave the EN/UVLO jumper (JU1) open. When of the long input cables and the ceramic capacitors at the JU1 is left open, the MAX17575 is enabled when the buck converter IC input. Table 1. Converter EN/UVLO Jumper (JU1) Settings SHUNT POSITION EN/UVLO PIN MAX17575 OUTPUT 1-2* Connected to VIN Enabled Connected to the center node of Enabled, UVLO level set through Not installed resistor-divider R1 and R2 the R1 and R2 resistors 2-3 Connected to SGND Disabled *Default position. Maxim Integrated 2 www.maximintegrated.com