SNVU916 May   2025

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
      1. 1.3.1 Application Circuit Diagram
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 Test Setup and Procedure
      1. 2.1.1 EVM Connections
      2. 2.1.2 Test Equipment
      3. 2.1.3 Recommended Test Setup
        1. 2.1.3.1 Input Connections
        2. 2.1.3.2 Output Connections
      4. 2.1.4 Test Procedure
        1. 2.1.4.1 Line and Load Regulation Efficiency
  9. 3Implementation Results
    1. 3.1 Test Data and Performance Curves
      1. 3.1.1 Conversion Efficiency
      2. 3.1.2 Operating Waveforms
        1. 3.1.2.1 Switching
        2. 3.1.2.2 Load Transient Response
        3. 3.1.2.3 Start-Up and Shutdown With ENABLE ON and OFF
        4. 3.1.2.4 Start-Up and Shutdown with EN Tied to VIN
  10. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Layout
    3. 4.3 Bill of Materials
  11. 5Device and Documentation Support
    1. 5.1 Device Support
      1. 5.1.1 Development Support
    2. 5.2 Documentation Support
      1. 5.2.1 Related Documentation
        1. 5.2.1.1 PCB Layout Resources
        2. 5.2.1.2 Thermal Design Resources
  12. 6Additional Information
    1. 6.1 Trademarks

1.1 Introduction

The LM25139-Q1EVM-440 high-density EVM is designed to use a regulated or non-regulated high-voltage input rail ranging from 5.5V to 36V to produce a tightly-regulated output voltage of 5V at load currents up to 12A. This wide VIN range DC/DC design offers outsized voltage rating and operating margin to withstand supply rail voltage transients.

The free-running switching frequency is 440kHz and is synchronizable to an external clock signal at a higher or lower frequency. The power-train passive components selected for this EVM, including buck inductors and ceramic input and output capacitors, are available from multiple component vendors.

The default configuration of this EVM uses a series resistor (R8) to sense the output current. Alternatively, the EVM can be configured for inductor DCR sensing by making the following changes:

  1. Replace R8 with a 0Ω resistor.
  2. DNP R19 and R20.
  3. Populate R18 with a 0Ω resistor.
  4. Populate R17 and C29. Refer to the device data sheet to select component values.

The LM25139-Q1 synchronous buck controller used in the EVM has the following features:

  • Wide input voltage (wide VIN) range of 3.5V to 42V
  • Spread spectrum modulation for lower EMI
  • Wide duty cycle range with low tON(min) and tOFF(min)
  • Ultra-low shutdown and no-load standby quiescent currents
  • Peak current-mode control loop architecture
  • Integrated, high-current MOSFET gate drivers
  • Cycle-by-cycle overcurrent protection with hiccup
CAUTION:
LM25139-Q1EVM-440
Hot surface. Contact can cause burns. Do not touch.