SNVU751 October   2020 LP875761-Q1

 

  1. 1Trademarks
  2. 2Overview
  3. 3Quick Setup Guide
    1. 3.1 Installing/Opening the Software
    2.     5
    3. 3.2 Power Supply Setup
    4. 3.3 Notes on Efficiency Measurement Procedure
  4. 4GUI Overview
    1. 4.1 Main Tab
    2. 4.2 Other Tabs and Menus
    3. 4.3 Console
  5. 5Bill of Materials
  6. 6Board Layout
  7. 7LP875761Q1EVM Schematics
  8. 8Revision History

Notes on Efficiency Measurement Procedure

Output Connections: An appropriate electronic load or high-power system source meter instrument, specified for operation down to 500 mV, is desirable for loading the UUT. The maximum load current is specified as 4 A per phase. Be sure to choose the correct wire size when attaching the electronic load. A wire resistance that is too high will cause a voltage drop in the power distribution path which becomes significant compared to the absolute value of the output voltage. Connect an electric load to J13. It is advised that, prior to connecting the load, it be set to sink 0 A to avoid power surges or possible shocks.

Voltage drop across the PCB traces will yield inaccurate efficiency measurements. For the most accurate voltage measurement at the EVM, use J6 (unpopulated through-hole) to measure the input voltage and J1 (unpopulated through-hole) to measure the output voltage.

To measure the current flowing to/from the UUT, use the current meter of the DC power supply/electric load as long as it is accurate. Some power source ammeters may show offset of several milliamps and thus will yield inaccurate efficiency measurements. In order to perform very accurate Iq measurements on the UUT, disconnect input protective Zener diode D1 by removing the shunt J5 from the board. When connected, this diode will cause some leakage, especially on high VIN voltages.