SLVUDH5A September   2025  – November 2025

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 U1: Solder Reflow
    3. 1.3 Kit Contents
    4. 1.4 Specification
    5. 1.5 Device Information
  7. 2Hardware
    1. 2.1 Power Requirements
    2. 2.2 Recommended Test Equipment
    3. 2.3 External Connections for Easy Evaluation
    4. 2.4 Test Points
    5. 2.5 Oscilloscope Probes: Probing the EVM
  8. 3Hardware Design Files
    1. 3.1 Schematics
    2. 3.2 PCB Layouts
    3. 3.3 PCB Layout Guidelines
    4. 3.4 PCB Layout Example
    5. 3.5 Bill of Materials (BOM)
    6.     Trademarks
  9. 4Revision History

2.3 External Connections for Easy Evaluation

The UCC35131EVM-118 utilizes screw terminals for quickly connecting to VIN, VDD and VEE. Connecting the appropriate ammeters and voltmeters, as shown in Figure 2-1, allows accurate EVM efficiency measurements to be made.

Connecting test equipment:

  1. Move shunt jumper, SH-J1 into the J2, 1-2, EN OFF position. This makes sure that the EVM cannot start while test equipment is being connected.
  2. Connect a +5V DC bias power supply J1:1-2 (+3.3V to +5V). Set the power supply to 0V. The +5V supply at J1 serves as the pullup bias for /PG and ENA. Turn off/disable the +5V DC Bias power supply.
  3. Connect the VIN DC power supply capable of 5V < VIN < 20V, 500mA at J3:1-2 (VIN). Adjust the power supply to 12V, and set the current limit to 1A. Turn off/disable the VIN power supply.
  4. Connect a variable load between J4:1 (VDD) and J4:2 (COM). If using an electronic load, set to constant resistance (CR), 450Ω (~500mW). Leave the load disabled until the EVM is powered.
  5. Connect a second load between J4:2 (COM) and J4:3 (VEE). If using an electronic load, set to constant resistance (CR), 2.5kΩ (~10mW). Leave the load disabled until the EVM is powered. Since the required load is small, a through-hole, 500mW, load resistor can be connected between J4:2-3.
  6. Some electronic loads are not able to regulate/stabilize CC when setting in the low mA range. Monitor the input current and load currents by inserting ammeters as shown in Figure 2-1. A current probe can be used with the oscilloscope to verify the stability of the DC current being regulated by an electronic load.
UCC35131EVM-118 Typical Efficiency Measurement Setup Figure 2-1 Typical Efficiency Measurement Setup

Power on for start-up:

  1. Verify VIN and +5V DC bias power supplies are off-disabled and no voltage is applied to the UUT
  2. Move shorting jumper, SH-J1, into the J2:2-3, EN ON position. NOTE: removing the shorting jumper, SH-J1 also results in EN ON.
  3. Turn on the VIN DC power supply. Verify 12V is present at TP1-to-TP3
  4. Verify the loads on VDD and VEE are disabled
  5. Turn on the +5V DC bias power supply. EVM is now enabled with VDD and VEE in regulation under no load condition.
  6. Verify +15V present on VDD-COM, and -5V present on VEE-COM
  7. Enable the load on VDD, enable the load on VEE
  8. The UCC35131-Q1 is now regulating VDD and VEE and processing ~0.5W of isolated output power
  9. Vary VIN between 5.5V < VIN < 20V, vary IVDD between 0mA < IVDD < 133mA, Vary IVEE between 0mA<IVEE<150mA. Max power capability is reduced from 2W for VIN<12V, VIN>18V. If max power is exceeded, the EVM shuts down. In this case, remove the loads from VDD and VEE, restart VIN (or toggle EN) and verify EVM return to normal operation before slowly increasing VDD and/or VEE loads.
  10. Insert oscilloscope probes into TP9, TP10 and TP11 for measuring VEE, VDD and VIN startup, steady state and AC ripple voltage

Power off for shutdown:

  1. Move shorting jumper SH-J1 into the J2:1-2, EN OFF position
  2. Turn off +5V, DC bias power supply
  3. Disable IVDD load
  4. Disable IVEE load
  5. Turn off VIN power supply