SLVUCX4 October   2024

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  7. 2Hardware
    1. 2.1 EVM Connections
    2. 2.2 Test Equipment
    3. 2.3 EVM Setup
      1. 2.3.1 Input Connections
      2. 2.3.2 Output Connections
      3. 2.3.3 Heat Sink Setup
  8. 3Implementation Results
    1. 3.1 Test Data and Performance Curves
      1. 3.1.1 Efficiency and Load Regulation Performance
      2. 3.1.2 Waveforms and Plots
      3. 3.1.3 EMI Performance
      4. 3.1.4 Thermal Performance
  9. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Layout
    3. 4.3 Bill of Materials
  10. 5Additional Information
    1. 5.1 Trademarks
  11. 6Device and Documentation Support
    1. 6.1 Device Support
      1. 6.1.1 Development Support
        1. 6.1.1.1 Custom Design With WEBENCH® Tools
    2. 6.2 Documentation Support
      1. 6.2.1 Related Documentation

2.1 EVM Connections

Working at an ESD-protected workstation, make sure that any wrist straps, bootstraps, or mats are connected and referencing the user to earth ground before power is applied to the EVM.

LM644A2QEVM-S2100T EVM Test Setup Figure 2-1 EVM Test Setup
Table 2-1 EVM Power Connections
LABELDESCRIPTION
VIN+Positive input power connection.
VIN–Negative input power connection.
VIN_EMI+Positive input power connection for EMI test.
VIN_EMI-Negative input power connection for EMI test.
VOUT+Positive output power connection.
VOUT–Negative output power connection.
Table 2-2 EVM Signal Connections
LABELDESCRIPTION
VINS+Positive input sense pin for measuring efficiency.
VINS–Negative input sense pin for measuring efficiency.
VOUTS+Positive output sense pin for measuring efficiency, and line and load regulation.
VOUTS–Negative output sense pin for measuring efficiency, and line and load regulation.
GNDGround reference point
SYNC(+)Positive synchronization pulse input.
SYNC(-)Negative synchronization pulse input.
MODELight load switching mode selection. Connect pin1 and pin2 for a FPWM mode. Connect pin2 and pin3 for an AUTO mode. Remove any jumper when external synchronization pulse is applied to SYNC.
DITHSpread spectrum enable, disable. Connect pin1 and pin2 to disable the spread spectrum. Remove any jumper to enable the spread spectrum. The EVM must restart after changing the jumper setting.
EN1Primary enable, disable. Connect pin1 and pin2 to enable both channels. Connect pin2 and pin3 to disable both channels. Remove any jumper when programing the line UVLO using an external resistor divider. Populate the external UVLO resistor divider.
EN2CH2 enable, disable. Connect pin1 and pin2 to enable CH2. Connect pin2 and pin3 to disable CH2. Remove any jumper when programing the line UVLO using an external resistor divider. Populate the external UVLO resistor divider.
VSELOutput voltage selection. Remove any jumper when programing the regulation target using an external resistor divider. The default condition is open. Connect pin 1 and pin 2 for a fixed 5V output. Connect pin 2 and pin 3 for a fixed 3.3V output. The external feedback resistors must be unpopulated to use the fixed output options.
PGProbe point for power good indicator. A pullup resistor is connected to VCC.
SYNCOUTProbe point for SYNCOUT signal. SYNCOUT provide clock information from the primary to the secondary device in 4- or 6-phase configuration.
SSProbe point for SS. The soft-start pin is also used for fault communication between the primary and the secondary device in 4- or 6-phase configuration.
COMPProbe point for COMP. COMP is the output of error amplifier.