SLUUCJ2 July   2021 UCC14240-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Pin Configuration and Functions
  3. 2Description
    1. 2.1 EVM Electrical Performance Specifications
  4. 3Schematic
  5. 4EVM Setup and Operation
    1. 4.1 Reference
    2. 4.2 External Connections for Easy Evaluation
    3. 4.3 Powering the EVM
      1. 4.3.1 Power on for Start-up
      2. 4.3.2 Power off for Shutdown
    4. 4.4 EVM Test Points
    5. 4.5 Oscilloscope Probes: Probing the EVM
  6. 5 Performance Data
    1. 5.1 Efficiency Data
    2. 5.2 Regulation Data
    3. 5.3 Start-up Waveforms
    4. 5.4 Inrush Current
    5. 5.5 AC Ripple Voltage
    6. 5.6 EN and /PG Timing
    7. 5.7 Shutdown
    8. 5.8 Steady State
    9. 5.9 Thermal Performance
  7. 6Assembly and Printed Circuit Board (PCB) Layers
  8. 7Bill of Materials (BOM)
  9. 8Revision History

External Connections for Easy Evaluation

The UCC14240EVM-052 EVM uses screw terminals for quickly connecting to the VIN, VDD ,and VEE pins. Connect the appropriate ammeters and voltmeters, as shown in Figure 4-1, to get accurate EVM efficiency measurements.

Connecting Test Equipment

  1. Move jumper J3 into the 1-2, EN OFF position. This assures the EVM cannot start while test equipment is being connected.
  2. Connect a +5 V DC bias power supply J1:1-2 (+3.3 V to +5 V). Set the power supply to 0 V. The +5 V supply at J1 serves as the pullup bias for /PG and ENA. Turn off/disable the +5V DC Bias power supply.
  3. Connect the VIN DC power supply capable of 21 V<VIN<27 V, 200 mA at J5:1-2 (VIN). Adjust the power supply to 24 V, and set the current limit to 300 mA. Set the power supply to 24 V. Turn off/disable the VIN power supply.
  4. Connect a variable load between J2:1 (VDD) and J2:3 (VEE). If using an electronic load, set to constant current (CC), 80 mA. Leave the load disabled until the EVM is powered.
  5. Connect a second load between J2:2 (COM) and J2:3 (VEE). If using an electronic load, set to constant current (CC), 10 mA. Leave the load disabled until the EVM is powered.
  6. Some electronic loads may not be able to regulate/stabilize CC when setting in the low mA range. Monitor the input current and load currents by inserting ammeters as shown in Figure 4-1. Use a current probe with the oscilloscope to verify the stability of the DC current being regulated by an electronic load.
GUID-20210719-CA0I-GXLW-FCXL-JDPGHRJB1KPJ-low.gif Figure 4-1 Typical Efficiency Measurement Setup