Texas Instruments UCC28950EVM-442

Overview

UCC28950EVM-442 from Texas Instruments is a 600-W phase-shifted full-bridge evaluation module designed to demonstrate ZVS operation of the UCC28950 PWM controller across 50–100% load, delivering regulated 12-V output from 370–410-V DC input with peak efficiency of 95.6% and ≤200-mV output ripple.

For engineers reviewing the UCC28950EVM-442 datasheet, UCC28950EVM-442 test setup, UCC28950EVM-442 application notes, or UCC28950EVM-442 alternative evaluation platforms, this module provides validated reference design data for high-density server and telecom power supplies requiring ZVS, burst-mode no-load management, and voltage-loop stability verification at 2–6 kHz crossover.

Technical Context

The UCC28950EVM-442 implements a complete phase-shifted full-bridge topology with primary-side MOSFETs (SPP20N60CFD), secondary synchronous rectifiers (FDP032N08), gate-drive transformers (56PR3362), and current-sense transformer (PE63587), all coordinated by the UCC28950PW TSSOP-24 controller.

It supports ZVS down to 50% load and transitions to valley switching below 25 A, while DCM logic disables synchronous rectifiers under light loads (<20%) to prevent negative inductor current and reduce drive losses-verified via differential probe measurements on Q3d–Q4d nodes and gate waveforms.

Key Specifications

Availability

UCC28950EVM-442 is available at Aetrix Electronics and suitable for server power supply development, telecom rectifier validation, and industrial high-density DC–DC converter prototyping requiring stable component supply, repeatable ZVS characterization, and pre-validated control loop performance.

Supply support for UCC28950EVM-442 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management technologies for industrial, automotive, and communications markets.

The UCC28950EVM-442 belongs to TI's high-efficiency power conversion evaluation platform family, engineered specifically to accelerate adoption of phase-shifted full-bridge topologies in 80 PLUS-compliant server and telecom power supplies.

FAQ

What is the primary purpose of the UCC28950EVM-442?

The UCC28950EVM-442 is a Texas Instruments evaluation module built to demonstrate the UCC28950 PWM controller in a 600-W phase-shifted full-bridge configuration. It validates ZVS operation from 50% to 100% load, burst-mode efficiency at no-load, and voltage-loop stability-providing engineers with a ready-to-test reference design for high-efficiency server and telecom power supplies. The UCC28950EVM-442 includes full schematics, test point definitions, and measured performance data per SLUU421A.

Does the UCC28950EVM-442 include input under-voltage lockout (UVLO)?

No, the UCC28950EVM-442 does not include input UVLO circuitry. As stated in Section 9 of SLUU421A, it is explicitly designed as a demonstration platform-not a standalone power supply-and requires the user to apply input voltage strictly within the 370–410-V DC range before enabling the 12-V bias supply. Applying voltage outside this range risks irreversible damage. The UCC28950EVM-442 relies on external supervision for safe startup sequencing.

What test equipment is required to characterize the UCC28950EVM-442?

Per Section 6 of SLUU421A, essential test equipment includes a 500-V/750-W DC source, 0–20-V bias supply, 4-channel 100-MHz oscilloscope with differential probes rated for 500 V, network analyzer for loop gain/phase measurement at TP4/TP5, precision shunt resistors (5 A/100 mV and 50 A/50 mV), and a 400-LFM fan. Voltmeters must measure up to 4 V, and output loading requires a 25-V/750-W electronic or resistive load. The UCC28950EVM-442 test points (TP1–TP9) are defined in Table 2 for consistent probing.

How does the UCC28950EVM-442 manage light-load efficiency?

The UCC28950EVM-442 uses two complementary techniques: burst mode and DCM (Discontinuous Conduction Mode). Below ~20% load, the UCC28950 controller disables synchronous rectifiers to prevent negative inductor current and eliminate gate-drive losses; at no load, it enters burst mode-reducing total system power consumption to under 500 mW. Measured data in Table 3 and Figure 23 confirm this behavior at VIN = 390 V and IOUT = 0 A. The UCC28950EVM-442 implements these functions directly via the UCC28950PW controller without external circuitry.

Can the UCC28950EVM-442 be used as a production-ready power supply?

No-the UCC28950EVM-442 is intended solely for engineering development, demonstration, and evaluation purposes per TI's Evaluation Board Important Notice. It lacks safety certifications (UL, CE, FCC), EMI filtering, input UVLO, overtemperature protection, and environmental compliance (RoHS/WEEE) required for end-product deployment. Its open construction, exposed high-voltage nodes (>370 V), and absence of regulatory markings mean it must only be operated by trained personnel using appropriate safety gear. The UCC28950EVM-442 serves as a design reference-not a drop-in solution.