SLVUBZ2A September   2020  – December 2020 LM5127-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Applications
    2. 1.2 Features
  3. 2EVM Setup
    1. 2.1 EVM Characteristics
  4. 3EVM Photo
  5. 4Testing Procedures
    1. 4.1 EVM Connectors and Test Points
  6. 5Test Results
    1. 5.1 Efficiency
    2. 5.2 Thermal Performance
    3. 5.3 Steady State
    4. 5.4 Load Transient
    5. 5.5 Line Transient Responses
  7. 6Schematics, PCB Layers, and Bill of Materials
    1. 6.1 Schematics
    2. 6.2 PCB Layers
    3. 6.3 Bill of Materials
  8. 7EVM Modifications
    1. 7.1 Configure Channel 1 as a Buck Controller
      1. 7.1.1 Component Modifications
      2. 7.1.2 CFG/MODE Pin Selection
    2. 7.2 Configure Channel 2 and Channel 3 as a Dual Phase Buck Controller
      1. 7.2.1 Component Modifications
      2. 7.2.2 CFG/MODE Pin Selection
    3. 7.3 EVM Modification Test Setups
  9. 8Revision History

1.2 Features

The LM5127EVM-FLEX has the following features :

  • Wide input voltage range from 3 V to 18 V
    • 5 V required for start-up
    • Maximum transient voltage of 42 V
  • Operating frequency of 440 kHz with external clock synchronization up or down by 20%
  • Bypass mode operation when channel 1 is configured as a boost controller.
  • LDO mode operating when VIN ≅ VOUT for channels configured as a buck controller.
  • Selectable forced-PWM (FPWM), skip mode or diode emulation mode (DEM) using the CFG/MODE pin
  • Tightly regulated buck output voltages of 5 V and 3.3 V with better than ±1% set point accuracy
    • Fixed output voltage of 5 V or 3.3 V using internal low leakage current, high impedance feedback resistors
    • Programmable output voltage with external feedback resistors adjustable from 0.8 V to 42 V
  • High power conversion efficiency across wide load current ranges:
    • Half-load efficiency of 94.2% at VIN = 13.5 V, IOUT2 = 2.5 A, IOUT3 = 3.5 A, RCFG = 19.1 kΩ
    • Full-load efficiency of 93.8% at VIN = 13.5 V, IOUT2 = 5 A, IOUT3 = 7 A, RCFG = 19.1 kΩ
  • Over current protection configurable by the RES pin
    • Hiccup mode short circuit protection, cycle-by-cycle peak current limiting, latch-off peak current limiting
  • Selectable output voltage with low leakage, high impedance, internal feedback resistor when a channel is configured a buck controller
  • Optional frequency dithering for improved EMI performance
  • Enable pins (EN1, EN2, EN3) and Power good (PGOOD1, PGOOD2, PGOOD3) indicators for each channel
  • Adjustable soft-start for each channel (SS1, SS2, SS3)
  • Programmable wake-up and sleep voltage threshold (DIS/BMOUT pin).
  • Overvoltage protection for each channel
  • Flexible Topology capable for multiple configurations. See Section 7 for details.
    • Flexible topology on channel 1 (boost controller or buck controller)
    • Single output or dual phase interleaved buck controllers (channel 2 and channel 3)