SLVUAP3A April   2016  – October 2021 TPS54202

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Background
    2. 1.2 Performance Specification Summary
    3. 1.3 Modifications
      1. 1.3.1 Output Voltage Set Point
      2. 1.3.2 Output Capacitor and Feed-Forward Capacitor
      3. 1.3.3 Adjustable UVLO
  3. 2Test Setup and Results
    1. 2.1 Input/Output Connections
    2. 2.2 Efficiency
    3. 2.3 Output Voltage Load Regulation
    4. 2.4 Output Voltage Line Regulation
    5. 2.5 Load Transients
    6. 2.6 Output Voltage Ripple
    7. 2.7 Input Voltage Ripple
    8. 2.8 Powering Up
    9. 2.9 Powering Down
  4. 3Board Layout
    1. 3.1 Layout
  5. 4Schematic and Bill of Materials
    1. 4.1 Schematic
    2. 4.2 Bill of Materials
  6. 5Revision History

1.3.3 Adjustable UVLO

The under voltage lock out (UVLO) can be adjusted externally using R4 and R5. The EVM is set for a start voltage of 6.74 V and a stop voltage of 5.83 V using R4 = 510 kΩ and R5 = 105 kΩ. Use Equation 4 and Equation 5 to calculate required resistor values for different start and stop voltages. For higher light-load efficiency, consider choosing a larger R4 and R5. Make adjustments to VSTART or VSTOP for a proper R4.

Equation 4. GUID-9C9EA9A6-4E37-49A8-851C-7B9A1089E77C-low.gif
Equation 5. GUID-49AC0FDD-61F4-46CC-A3FC-540774445FFD-low.gif

Ip = 0.7 µA, Ih = 1.55 µA, VENFALLING = 1.19 V and VENRISING = 1.22 V