SLUUCE9A December   2020  – April 2021 TPS543820 , TPS543820E

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Background
    2. 1.2 Before You Begin
    3. 1.3 Performance Characteristics Summary
  3. 2Configurations and Modifications
    1. 2.1 Output Voltage
    2. 2.2 Switching Frequency (FSEL Pin)
    3. 2.3 Current Limit, Soft-Start Time, and Internal Compensation (MODE Pin)
    4. 2.4 Adjustable UVLO
  4. 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  Input Voltage Ripple
    7. 3.7  Synchronizing to a Clock
    8. 3.8  Start-up and Shutdown with EN
    9. 3.9  Start-up and Shutdown with VIN
    10. 3.10 Start-up Into Pre-Bias
    11. 3.11 Hiccup Current Limit
    12. 3.12 Overvoltage Protection
    13. 3.13 Thermal Performance
  5. 4Board Layout
    1. 4.1 Layout
  6. 5Schematic and Bill of Materials
    1. 5.1 Schematic
    2. 5.2 Bill of Materials
  7. 6Revision History

2.3 Current Limit, Soft-Start Time, and Internal Compensation (MODE Pin)

In the U2 design, jumper J18 can be used to select between the current limit, soft-start time, and internal compensation options shown in Table 2-3. If the desired option is not available, change one of the resistors to the value which sets the desired option.

In the U1 design, change the MODE resistor to the value which sets the desired option.

Table 2-3 MODE Selection
JUMPER SETTING MODE RESISTOR CURRENT LIMIT SOFT-START TIME RAMP
1 to 2 pin shorted 2.21 kΩ High 1 ms 1 pF
3 to 4 pin shorted(1) 4.87 kΩ High 1 ms 2 pF
5 to 6 pin shorted 11.3 kΩ High 1 ms 4 pF
7 to 8 pin shorted 60.4 kΩ Low 1 ms 2 pF
(1) Default Setting