SLUUCY1 November   2023

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  7. 2Hardware
    1. 2.1 Configurations and Modifications
      1. 2.1.1 Output Voltage
      2. 2.1.2 Switching Frequency (FSEL Pin)
      3. 2.1.3 Current Limit, Soft-Start Time, and Internal Compensation (MODE Pin)
      4. 2.1.4 Adjustable UVLO
    2. 2.2 Input/Output Connections
    3. 2.3 Best Practices
  8. 3Implementation Results
    1. 3.1 Performance Characteristics Summary
  9. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Layout
      1. 4.2.1 Layout
    3. 4.3 Bill of Materials
  10. 5Additional Information
    1.     Trademarks

2.2 Input/Output Connections

This section describes how to properly connect, set up, and use the TPS543B25T evaluation module.

The TPS543B25T is provided with input connectors, output connectors, and test points as shown in Table 3-1 and Table 3-2.

To support the minimum input voltage with the full rated load on both outputs with the default EVM, a power supply capable of supplying greater than 30 A must be connected to J1 through a pair of 18-AWG wires or better.

For U1, the load must be connected to J2 and J3. Two pair of 18-AWG wires or better must be used for each connection. With the maximum current limit setting, the maximum load current capability is near 25 A before the TPS543B25T goes into current limit. Wire lengths must be minimized to reduce losses in the wires.

Test point TP2 provides a place to monitor the VIN input voltage with TP6 providing a convenient ground reference for U1. TP4 is used to monitor the output voltage of U1 with TP10 as the ground reference.

If modifications are made to the TPS543B25T, then the input current can change. The input power supply and wires connecting the EVM to the power supply must be rated for the input current.

Note: For the FSEL pin of the TPS543B25T to correctly detect the resistor value connected to ground, the buffers on the EVM need to be provided a VCC voltage of 2 V to 5.5 V to go high impedance.
Table 2-1 Connectors and Jumpers
REFERENCE DESIGNATOR NAME RELATED IC FUNCTION
J1 VIN U1 VIN screw terminal to connect input voltage (see Table 3-2 for VIN range).
J2 VOUT U1 PGND

ground
J3

GND

 U1 VOUT screw terminal to connect load to output.
J4 EN_OFF U1 2-pin header for enable. Add shunt to connect EN to ground and disable device.
J5 ENSYNC U1 2-pin header to connect U2 buffer output enable to ground. Populate shunt to enable output of buffer. Remove shunt to make buffer output high impedance.
Table 2-2 Test Points
REFERENCE DESIGNATOR NAME RELATED IC FUNCTION
TP1 VOUT U1 SMB connector to measure output voltage. When using this test point, the scope must be set for 1-MΩ termination. When using 50-Ω termination, a 2:1 divider is created.
TP2 VIN U1 VIN test point. Use this for efficiency measurements.
TP3 SW U1 SW node solder mask opening.
TP4 VOUT U1 VOUT test point. Use this for efficiency, output regulation, and bode plot measurements.
TP5 EN U1 EN test point. If user is applying an external voltage, then the external voltage must be kept below the absolute maximum voltage of the EN pin of 6 V.
TP6 PGND U1 PGND test point. Use this for efficiency measurements.
TP7 PGOOD U1 PGOOD test point.
TP8 AGND U1 AGND test point.
TP9 BODE+ U1 Used for Bode plot measurements.
TP10 PGND U1 PGND test point. Use this for efficiency measurements.
TP11 BODE- U1 Test point between voltage divider network and output voltage. Used for Bode plot measurements.
TP12 VCC_BUF U1 VDRV Voltage Supply to Buffer.
TP13 PGND U1 PGND test point.
TP14 SYNC U1 SYNC test point.
TP15 ISNS U1 Test point to measure current in load transient circuit. Gain is 20 A/V.
TP16 FGEN U1 Test point to connect function generator to load transient circuit. Slowly increase amplitude and vary slew rate of function generator for desired load step.
TP17 ISNS U1 Test point to measure current in load transient circuit. Gain is 20 A/V.
TP18 PGND U1 PGND test point.