SLVUBQ1A August   2020  – May 2021 TPS543620

 

  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

2.2 Switching Frequency (FSEL Pin)

In the U2 design, jumper J17 can be used to select between the switching frequency options shown in Table 2-2. 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 FSEL resistor to the value which sets the desired option.

Table 2-2 FSEL Selection
JUMPER SETTINGFSEL RESISTORSWITCHING FREQUENCY
1 to 2 pin shorted17.4 kΩ750 kHz
3 to 4 pin shorted(1)11.8 kΩ1000 kHz
5 to 6 pin shorted8.06 kΩ1500 kHz
7 to 8 pin shorted4.99 kΩ2200 kHz
(1) Default Setting