SLVUDY5A July   2026  – July 2026

 

  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
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 EVM Setup
      1. 2.1.1 Quick Start
      2. 2.1.2 Test Points
  9. 3Implementation Results
    1. 3.1 Performance Data and Results
      1. 3.1.1 Efficiency, Load Regulation, and Noise
      2. 3.1.2 Load Transients
      3. 3.1.3 Start-Up and Shutdown
  10. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 Board Layout
    3. 4.3 Bill of Materials
  11. 5Additional Information
    1. 5.1 Trademarks
  12. 6Revision History

2.1 EVM Setup

This section describes the test points and connectors on the EVM and how to properly connect, set up, and use the LMR61440QEVM.

The EVM uses the LMR61440-Q1 converter, which includes MODE/SYNC capability. This capabilityu means that the device can operate in pulse frequency modulation (PFM) light-load mode when this pin is tied to GND. TI has observed additional output voltage ripple at input voltages close to the output voltage when the device is operating in PFM light-load mode. To see improved performance, TI recommends to configure the EVM to operate in forced pulse width modulation (FPWM) mode.

LMR61440QEVM EVM Board Connections Figure 2-1 EVM Board Connections

The test setup consists of the following instruments in addition to the EVM board:

  • Power supply: the input DC voltage source must be capable of supplying 36V and 4A.
  • Load: the load must be an electronic, constant-current (CC) or constant-resistance (CR) mode load, capable of supporting 4A of load current at 3.3V. Disconnect the electronic load when performing no-load input current tests.
  • Multimeters:
    • Voltmeter 1: measures input voltage at VIN (TP1) and GND (TP2).
    • Voltmeter 2: measures output voltage at VOUT (TP3 or VOUTS) and GND (TP4).
    • Ammeter 1: measures input current.
    • Ammeter 2: measures output current.
  • Oscilloscope: with the scope set to 20MHz bandwidth and AC coupling, measure the output voltage ripple directly across an output capacitor with a short ground lead. Place the oscilloscope probe tip on the positive terminal of the output capacitor, and the ground lead on the negative terminal of the output capacitor. TI does not recommend using a long-leaded ground connection because the connection can induce additional noise due to a large ground loop. To measure other waveforms, adjust the oscilloscope as necessary.
  • Load current transient:

    A load transient generator is provided on the EVM. Connect a suitable pulse generator to the "LS_gate" SMB connector and adjust the load current pulse amplitude and duration as desired, while monitoring the voltage at J2. A 10mΩ sense resistor is used, providing a scale factor of 10mV/A. The pulse duty cycle must be kept low to avoid damaging the MOSFET. The output voltage can be monitored use the VOUTS SMB or directly across the output capacitors. TI recommends use of a high speed differential probe. See also Figure 2-2.

LMR61440QEVM Load Transient Generator Figure 2-2 Load Transient Generator