MAXREFDES1047: wide input range, 5V/3A output synchronous rectification, step-down DC-DC converter, two-layer circuit board design to reduce costs

MAXREFDES1047 is based on the high-voltage, synchronous rectification buck converter MAX17504, which implements efficient DC-DC step-down conversion and outputs 5V@3A. To reduce costs, this reference design provides a 2-layer PCB layout and complete test data. MAX17504 has a built-in MOSFET and operates in the input voltage range of 4.5V to 60V. The output voltage can be set from 0.9V to 90%VIN. This reference design uses a fixed output of 5V. The device operates over the -40°C to +125°C temperature range, and the feedback voltage regulation accuracy is within ±1.1%. The MAX17504 uses a peak current control architecture. The device can operate in pulse width modulation (PWM), pulse frequency modulation (PFM) or discontinuous conduction (DCM) modes. The programmable soft-start function allows users to reduce input inrush current, and provides an output enable/undervoltage lockout control pin (EN/UVLO), allowing users to turn on the power supply when the input voltage reaches the corresponding requirements. When the output voltage reaches the regulated range, the RESET output is triggered after a certain delay to provide a power-ready indication for the system.

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Key Features

• 2-layer board layout reduces power consumption

• Reduces external component count and overall cost

• Reduce DC-DC regulator inventory quantity

• Reduce power consumption

• Ensure reliable operation in harsh industrial environments

design resources

Design, build and test

This document introduces the reference design shown in Figure 1 and provides detailed system technical guidance for designing a high-efficiency buck power supply using the MAX17504 step-down DC-DC converter. The power supply has been built and tested, please refer to this document for details.