SLVU097B October   2003  – October 2021 TPS54350

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Background
    2. 1.2 Performance Specification Summary
    3. 1.3 Modifications
      1. 1.3.1 Output Voltage Setpoint
      2. 1.3.2 Switching Frequency
      3. 1.3.3 Input Filter
      4. 1.3.4 UVLO Programming
      5. 1.3.5 Synchronization
      6. 1.3.6 Power Good
      7. 1.3.7 Synchronous Low-Side FET
      8. 1.3.8 Optional Output Filtering
  3. 2Test Setup and Results
    1. 2.1  Input/Output Connections
    2. 2.2  Efficiency
    3. 2.3  Power Dissipation
    4. 2.4  Output Voltage Regulation
    5. 2.5  Load Transients
    6. 2.6  Loop Characteristic
    7. 2.7  Output Voltage Ripple
    8. 2.8  Input Voltage Ripple
    9. 2.9  Gate Drive
    10. 2.10 Powering Up and Down
  4. 3Board Layout
    1. 3.1 Layout
  5. 4Schematic and Bill of Materials
    1. 4.1 Bill of Materials
  6. 5Revision History

1.3.7 Synchronous Low-Side FET

The TPS54350EVM-235 is provisioned with a external low-side FET for operation as a synchronous buck regulator. If desired, an external catch diode can be used in place of the FET. The pad for the diode is located on the back side of the PCB. Verify that the inductor is properly sized for operation without the low-side FET. The minimum value for the inductor when operating in this mode is given by Equation 5.

Equation 5. L m i n =   V O ( 1 -   V O V I ( m a x ) ) f s   × 0.6