SLVU677A August   2012  – August 2021 TPS54494

 

  1.   Trademarks
  2. 1Introduction
  3. 2Performance Specification Summary
  4. 3Modifications
    1. 3.1 Output Voltage Setpoint
    2. 3.2 Output Filter and Closed-Loop Response
  5. 4Test Setup and Results
    1. 4.1 Input/Output Connections
    2. 4.2 Start-Up Procedure
    3. 4.3 Efficiency
      1. 4.3.1 Efficiency of Converter 1
      2. 4.3.2 Efficiency of Converter 2
    4. 4.4 Load Regulation
      1. 4.4.1 Load Regulation of Converter 1
      2. 4.4.2 Load Regulation of Converter 2
    5. 4.5 Line Regulation
      1. 4.5.1 Line Regulation Converter 1
      2. 4.5.2 Line Regulation Converter 2
    6. 4.6 Load Transient Response
      1. 4.6.1 Load Transient Response Converter 1
      2. 4.6.2 Load Transient Response Converter 2
    7. 4.7 Output Voltage Ripple
      1. 4.7.1 Output Voltage Ripple Converter 1
      2. 4.7.2 Output Voltage Ripple Converter 2
    8. 4.8 Input Voltage Ripple
    9. 4.9 Start-Up
      1. 4.9.1 Converter 1 Start-Up
      2. 4.9.2 Converter 2 Start-Up
  6. 5Board Layout
    1. 5.1 Layout
  7. 6Schematic, Bill of Materials, and Reference
    1. 6.1 Schematic
    2. 6.2 Bill of Materials
    3. 6.3 Reference
  8. 7Revision History

Output Voltage Setpoint

To change the output voltages of the EVM, it is necessary to change the value of the top resistor of the feedback divider, R1 or R3. Please refer to the top assembly in Figure 5-1 to locate the resistors close to the output connectors. Changing the value of R1 or R3 can change the output voltage above 0.765 V. The value of R1 or R3 for a specific output voltage can be calculated using Equation 1.

For output voltage from 0.76 V to 7 V:

Equation 1. GUID-CD151B01-39BF-4D34-A2D2-FBF5BB5ABD7A-low.gif

Table 3-1 lists the R1 or R3 values for some common output voltages. For output voltages of 1.8 V or above, a feedforward capacitor (C21 or C20) may be required to improve the phase margin. Pads for this component (C21 or C20) are provided on the printed-circuit board. Note that the resistor values given in Table 3-1 are standard values and not the exact values calculated using Equation 1.

Table 3-1 Output Voltages
Output Voltage
(V)
R1, R3
(kΩ)
R2, R4
(kΩ)
C21, C20
(pF)
L1, L2
(µH)
C14, C15, C18 Total Capacitance,
C16, C17, C19 Total Capacitance
(µF)
16.8122.11.5 - 2.222 - 68
1.058.2522.11.5 - 2.222 - 68
1.212.722.11.5 - 2.222 - 68
1.521.522.11.5 - 2.222 - 68
1.830.122.15 - 222.2 - 3.322 - 68
2.549.922.15 - 222.2 - 3.322 - 68
3.373.222.15 - 222.2 - 3.322 - 68
512422.15 - 224.722 - 68
6.516522.15 - 224.722 - 68