SLVUCE3 april   2023 TPS54KB20

 

  1.    TPS54KB20EVM 25-A, Regulator Evaluation Module
  2.   Trademarks
  3. 1Introduction
    1. 1.1 Background
    2. 1.2 Before You Begin
    3. 1.3 Performance Characteristics Summary
  4. 2Configurations and Modifications
    1. 2.1 Output Voltage
    2. 2.2 Frequency and Operation Mode Setting (MSEL Pin)
  5. 3Test Setup and Results
    1. 3.1 Input/Output Connections
    2. 3.2 Efficiency
    3. 3.3 Output Voltage Regulation
    4. 3.4 Load Transient and Loop Response
    5. 3.5 Output Voltage Ripple
    6. 3.6 Start-up and Shutdown with EN
    7. 3.7 Thermal Performance
  6. 4Board Layout
    1. 4.1 Layout
  7. 5Schematic and Bill of Materials
    1. 5.1 Schematic
    2. 5.2 Bill of Materials

3.6 Start-up and Shutdown with EN

Figure 3-17 and Figure 3-18 show the start-up and shutdown waveforms for U2 with EN. In Figure 3-17, the input voltage is initially applied and the output is inhibited by pulling EN to GND using an external function generator. When the EN voltage is increased above the enable-threshold voltage, the start-up sequence begins and the output voltage ramps up to the externally set value. In Figure 3-18, the external function generator pulls EN to ground and the TPS54KB20 shuts down.

GUID-20230406-SS0I-HD8J-FHHD-8BKNHFF3ZVD8-low.svgFigure 3-17 U2 Start-up with EN – 25-A Load
GUID-20230411-SS0I-LCNQ-FWSB-NQFGCZCWGX39-low.svgFigure 3-18 U2 Shutdown with EN – 25-A Load