SLVUAM8B December   2015  – August 2021 TPS54A20

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Before You Begin
    2. 1.2 Background
    3. 1.3 Performance Specification Summary
    4. 1.4 Modifications
      1. 1.4.1 Output Voltage Setpoint
      2. 1.4.2 On Time
      3. 1.4.3 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  Loop Characteristics
    7. 2.7  Output Voltage Ripple
    8. 2.8  Input Voltage Ripple
    9. 2.9  Powering Up
    10. 2.10 Thermal Image
  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

1.4.3 Adjustable UVLO

The undervoltage lockout (UVLO) can be adjusted externally using R2 (REN(TOP)) and R3 (REN(BOT)). The EVM is set for a start voltage of 9.385 V and a stop voltage of 9.144 V using R2 = 80.6 kΩ and R3 = 12.4 kΩ. Use Equation 3 and Equation 4 to calculate required resistor values for different start and stop voltages. IEN(FALL) = 4 µA, IEN(RISE) = 1 µA and VEN = 1.23 V

Equation 3. GUID-366A8DCC-8D33-4F94-B428-A8154C102683-low.gif
Equation 4. GUID-71B0FD10-1612-4D1A-9860-D7C97E95F28F-low.gif