Click here for production status of specific part numbers. Evaluates: MAXM15466 5V MAXM15466 5V Output Output-Voltage Application Evaluation Kit General Description Quick Start The MAXM15466 5V output evaluation kit (EV kit) pro- Recommended Equipment vides a proven design to evaluate the MAXM15466 high- One 4.5V to 42V DC, 300mA power supply voltage, high-efficiency, synchronous step-down DC-DC 1.5W resistive load with 300mA sink capacity module. The EV kit is programmed to deliver 5V output for loads up to 300mA. The EV kit features an adjust- Four digital multimeters (DMM) able input undervoltage lockout, selectable mode, and MAXM15466EVKIT open-drain RESET signal. The MAXM15466 data sheet provides a complete description of the module that should Equipment Setup and Test Procedure be read in conjunction with this EV kit data sheet prior The EV kit is fully assembled and tested. Follow the steps to modifying the demo circuit. For full module features, below to verify the board operation. benefits and parameters, refer to the MAXM15466 data Caution: Do not turn on power supply until all sheet. connections are completed. 1) Set the power supply at a voltage between 4.5V and Features 42V. Then, disable the power supply. Highly Integrated Solution 2) Connect the positive terminal of the power supply to Wide 8.5V to 42V Input Range the VIN PCB pad and the negative terminal to the Fixed 5V Output, Delivers Up To 300mA Output nearest GND PCB pad. Connect the positive termi- Current nal of the 300mA load to the VOUT PCB pad and the High 85.01% Efficiency (V = 24V, V = 5V at negative terminal to the nearest GND PCB pad. IN OUT 150mA) 3) Connect the DVM (DMM in voltage-measurement 550kHz Switching Frequency mode) across the VOUT PCB pad and the nearest GND PCB pad. ENABLE/UVLO Input, Resistor-Programmable UVLO Threshold 4) Verify that shunt is not installed on jumper J1 (see Table 1 for details). PFM Feature for Better Light-Load Efficiency 5) Turn on the DC power supply. Fixed Internal 3.75ms Soft-Start Time 6) Enable the load. RESET Output, with Pullup Resistor to V CC 7) Verify that the DVM displays 5V. Overcurrent and Overtemperature Protection (OCP and OTP) Low-Profile, Surface-Mount Components Proven PCB Layout Ordering Information appears at end of data sheet. Fully Assembled and Tested Complies with CISPR22(EN55022) Class B Conducted and Radiated Emissions 319-100337 Rev 0 3/19Evaluates: MAXM15466 5V MAXM15466 5V Output Evaluation Kit Output-Voltage Application Input Capacitor Selection Detailed Description The input capacitor serves to reduce the current peaks The MAXM15466 EV kit is designed to demonstrate drawn from the input power supply and reduces switching salient features of MAXM15466 power module. The EV kit frequency ripple at the input. The input capacitance must includes an EN/UVLO PCB pad, and jumper J1, to enable be greater than or equal to the value given in Table 1 of the output at a desired input voltage. Jumper J2 allows MAXM15466 data sheet. Input capacitor C3 is chosen to selection of either PWM or PFM mode of operation based be 1F/50V. on light-load performance requirements. An additional RESET pad is available for monitoring if the converter Electro-Magnetic Interference (EMI) output voltage is in regulation. Compliance to conducted emissions (CE) standards Output Capacitor Selection requires an EMI filter at the input of a switching power converter. The EMI filter attenuates high-frequency cur- X7R ceramic output capacitors are preferred due to their rents drawn by the switching power converter, and limits stability over temperature in industrial applications. The the noise injected back into the input power source. required output capacitor (C5) for 5V output is selected from Table 1 of the MAXM15466 data sheet as 10F/16V. Use of EMI filter components as shown in Figure 1 in conjunction with the schematic results in lower con- Fixed Output Voltage ducted emissions below CISPR22 Class B limits. The The MAXM15466 is a fixed 5V output module. Connect MAXM15466 EV kit PCB layout is also designed to limit FB of MAXM15466 directly to VOUT for feedback control. radiated emissions from switching nodes of the power converter resulting in radiated emissions below CISPR22 Enable/Undervoltage-Lockout Class B limits. (EN/UVLO) Programming The MAXM15466 offers an adjustable input undervoltage- lockout feature. In this EV kit, for normal operation, leave jumper J1 open. When J1 is left open, the MAXM15466 VIN EMI is enabled when the input voltage rises above 8.5V. To V IN disable MAXM15466, install a jumper across pins 2-3 on L1 VIN EMI J1. See Table 1 for J1 settings. A potential divider formed by R1 and R2 sets the input voltage (V ) at which the 82H INU C C9 8 C7 module is enabled. The value of resistor R1 is chosen to be 2.2M, and R2 is calculated using the following 1F 0.68F 0.1F equation: R 1.215 1 R = 2 ( V 1.215 ) INU Figure 1. EMI Filter Components where R1 and R2 are in k, For MAXM15466 to turn on at 8.5V input, the Resistor R2 is calculated to be 374k. Table 1. UVLO Enable/Disable Configuration (J1) POSITION EN/UVLO PIN MAXM15466 OUTPUT Connected to the center node of resistor-divider Programmed to startup at desired input-voltage Not Installed* R1 and R2. level. 1-2 Connected to V Enabled if V is greater than V IN IN IN(MIN). 2-3 Connected to GND Disabled *Default position Maxim Integrated 2 www.maximintegrated.com