SLUUCA9A September   2020  – April 2021 TPS546B24A

 

  1.   Trademarks
  2. 1 Description
    1. 1.1 Before You Begin
    2. 1.2 Typical Applications
    3. 1.3 Features
  3. 2 Electrical Performance Specifications
  4. 3 Schematic
  5. 4 Test Setup
    1. 4.1 Test and Configuration Software
      1. 4.1.1 Description
      2. 4.1.2 Features
    2. 4.2 Test Equipment
      1. 4.2.1 Voltage Source
      2. 4.2.2 Multimeters
      3. 4.2.3 Output Load
      4. 4.2.4 Oscilloscope
      5. 4.2.5 Fan
      6. 4.2.6 USB-to-GPIO Interface Adapter
      7. 4.2.7 Recommended Wire Gauge
    3. 4.3 Tip and Barrel Measurement
    4. 4.4 List of Test Points, Jumpers, and Connectors
    5. 4.5 Evaluating Split Rail Input
    6. 4.6 Configuring EVM to Overdrive VDD5
    7. 4.7 Powering from a Single 3.3-V Input Power Supply
  6. 5 EVM Configuration Using the Fusion GUI
    1. 5.1 Configuration Procedure
  7. 6 Test Procedure
    1. 6.1 Line and Load Regulation and Efficiency Measurement Procedure
    2. 6.2 Efficiency Measurement Test Points
    3. 6.3 Control Loop Gain and Phase Measurement Procedure
  8. 7 Performance Data and Typical Characteristic Curves
    1. 7.1  Efficiency
    2. 7.2  Load and Line Regulation (Measured Between TP27 and TP26)
    3. 7.3  Transient Response
    4. 7.4  Control Loop Bode Plot
    5. 7.5  Output Ripple
    6. 7.6  Power MOSFET Drain-Source Voltage
    7. 7.7  Control On
    8. 7.8  Control Off
    9. 7.9  Control On With Pre-biased Output
    10. 7.10 Thermal Image
  9. 8 EVM Assembly Drawing and PCB Layout
  10. 9 Bill of Materials
  11. 10Using the Fusion GUI
    1. 10.1  Opening the Fusion GUI
    2. 10.2  General Settings
    3. 10.3  Changing ON_OFF_CONFIG
    4. 10.4  Pop-up for Some Commands While Conversion is Enabled
    5. 10.5  SMBALERT# Mask
    6. 10.6  Device Info
    7. 10.7  Phase Commands
    8. 10.8  All Config
    9. 10.9  Pin Strapping
    10. 10.10 Monitor
    11. 10.11 Status
  12. 11Revision History

4.7 Powering from a Single 3.3-V Input Power Supply

The EVM includes two charge pump options to enable powering the TPS546B24A from a single 3.3-V input supply. The operation of these charge pumps is discussed in the Powering the TPS546D24A Device Family from a Single 3.3-V Input Power Supply Application Report.

Before implementing the following instructions to use one of the charge pump circuits, it is first necessary to modify the conditions that enable power conversion. By default, the EVM is configured to start switching when PVIN goes above 4.7 V based on the R1 and R2 voltage divider to the EN pin. Increasing R2 from 8.66 kΩ to 16.2 kΩ sets the enable threshold to approximately 3.0 V. An alternative method is to use the Fusion GUI to change the On/Off Config setting to Always Converting such that the device is enabled whenever power is present, regardless of the state of the EN pin or the OPERATION command. The configuration screen is shown in Figure 10-3. Be sure to Store Config to NVM after writing the change to hardware such that the setting persists after power is removed and reapplied.

To use the discrete charge pump, modify the EVM as follows:

  1. Modify the enable threshold or On/Off Config of the device as described previously.
  2. Set SYNC pin as an output. This can be accomplished by doing either of the following:
    1. Populate ADRSEL pin-strap resistor divider with R9 = 2.05 kΩ and R10 = 10 kΩ.
    2. Use Fusion GUI to set the SYNC_DIR bits of the SYNC_CONFIG register to 01b: Enable SYNC OUT. This register can be set from the All Config tab in Fusion GUI, shown in Figure 10-8. Be sure to Store Config to NVM after writing the change to hardware.
  3. Remove the jumper JP3 to disconnect AVIN from both the external AVIN header (T1) and from PVIN.
  4. Populate the resistors R26, R27, and R29 with 0-Ω resistors.
  5. Apply PVIN input voltage. Note that the output voltage of the discrete charge pump will be approximately 2 × PVIN (minus two diode drops). Pay careful attention that the applied PVIN remains below 9 V such that the generated AVIN does not exceed the 18-V rating of the converter IC.

To use the charge pump IC TPS60150, modify the EVM as follows:

  1. Modify the enable threshold or On/Off Config of the device as described previously.
  2. Remove the jumper JP3 to disconnect AVIN from both the external AVIN header (T1) and from PVIN.
  3. Populate the resistors R30 and R31 with 0-Ω resistors.
  4. Apply PVIN input voltage. Pay careful attention that the applied PVIN remains below the 5.5-V input rating of the TPS60150 charge pump IC.
Note: Only one charge pump circuit should be connected and used at a time. Remove the 0-Ω resistors that connect the charge pump to PVIN and AVIN (and SYNC for the discrete charge pump) before connecting the other charge pump, or before testing other conditions with higher input voltages that do not require the charge pump.