SLVUCL2 july   2023 LMQ644A2-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1EVM Description
    1. 1.1 Features and Electrical Performance
  5. 2EVM Performance and Specifications
  6. 3EVM Photo
  7. 4Test Setup and Procedure
    1. 4.1 EVM Connections
    2. 4.2 Test Equipment
    3. 4.3 EVM Setup
      1. 4.3.1 Input Connections
      2. 4.3.2 Output Connections
  8. 5Test Data and Performance Curves
    1. 5.1 Efficiency and Load Regulation Performance
    2. 5.2 Waveforms and Plots
    3. 5.3 EMI Performance
    4. 5.4 Thermal Performance
  9. 6EVM Documentation
    1. 6.1 Schematic
    2. 6.2 Bill of Materials
    3. 6.3 PCB Layout
  10. 7Device and Documentation Support
    1. 7.1 Device Support
      1. 7.1.1 Development Support
        1. 7.1.1.1 Custom Design With WEBENCH® Tools
    2. 7.2 Documentation Support
      1. 7.2.1 Related Documentation

4.1 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.

GUID-20230519-SS0I-6WQ1-KNHN-MJCXCV9JWSPT-low.svg Figure 4-1 EVM Test Setup
Table 4-1 EVM Power Connections
LABELDESCRIPTION
VIN+Positive input power connection
VIN–Negative input power connection
VIN_EMI+Positive input power connection for EMI test. The minimum operating voltage is 12 V at this input.
VIN_EMI-Negative input power connection for EMI test. The minimum operating voltage is 12 V at this input.
VOUT+Positive output power connection
VOUT–Negative output power connection
Table 4-2 EVM Signal Connections
LABEL DESCRIPTION
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.
GND Ground reference point
SYNC(+) Positive synchronization pulse input.
SYNC(-) Negative synchronization pulse input.
MODE Light 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.
DITH Spread 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.
EN1 Primary 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.
EN2 CH2 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.
VSEL Output voltage selection. Remove any jumper when programing the regulation target using an external resistor divider. The default condition is open. Connect pin1 and pin2 for a fixed 5-V output. Connect pin2 and pin3 for a fixed 3.3-V output. The external feedback resistors must be unpopulated to use the fixed output options.
PG Probe point for power good indicator. A pullup resistor is connected to VCC.
SYNCOUT Probe point for SYNCOUT signal. SYNCOUT provide clock information from the primary to the secondary device in 4- or 6-phase configuration.
SS Probe 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.
COMP Probe point for COMP. COMP is the output of error amplifier.