Texas Instruments UCC25800EVM-037

Overview

UCC25800EVM-037 from Texas Instruments is an evaluation module for the UCC25800 open-loop LLC transformer driver IC, designed to deliver isolated ±18 V / –5 V bias power up to 2 W for SiC MOSFET and IGBT gate drivers in traction and industrial inverters. It operates from a 6–26 V DC input or accepts a regulated 15.6 V external supply directly at the LLC board, supporting both pre-regulated and direct-input configurations.

For engineers reviewing the UCC25800EVM-037 datasheet, UCC25800EVM-037 test setup, UCC25800EVM-037 application notes, or UCC25800EVM-037 thermal performance data, this module provides validated reference design implementation, CISPR-25 Class-5 EMI-compliant operation, and full characterization of startup behavior, load transients, ripple, and efficiency across input voltage and load conditions.

Technical Context

The UCC25800EVM-037 implements a two-stage architecture: a left-side pre-regulator (optional) generating 15.6 V from 6–26 V input, and a right-side LLC resonant converter based on the UCC25800AQDGNRQ1 driver IC. The LLC stage uses a Wurth Electronik 750319177 transformer with 1:1.67 turns ratio and 16.5 µH primary inductance to generate dual isolated outputs.

It supports external frequency synchronization via the SYNC pin (enabling 497 kHz base or 577 kHz locked operation), DIS-pin enable/disable control, over-current protection with FLT-pin reporting, and achieves 82.8% peak efficiency at 15.6 V input without pre-regulator - rising to 88.1% when output LDOs are bypassed.

Key Specifications

Availability

UCC25800EVM-037 is available at Aetrix Electronics and suitable for traction inverter development, industrial motor drive prototyping, and isolated gate driver power supply validation requiring stable component supply, traceable sourcing, and documented thermal/EMI performance.

Supply support for UCC25800EVM-037 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 specializing in analog, embedded processing, and power management technologies, with deep expertise in automotive-grade power conversion and isolation solutions.

The UCC25800EVM-037 belongs to TI's high-reliability bias power evaluation platform family, engineered specifically to accelerate development of isolated gate driver supplies for EV traction inverters and industrial motor drives.

FAQ

What is the primary function of the UCC25800EVM-037?

The UCC25800EVM-037 is an evaluation module that demonstrates the UCC25800 open-loop LLC transformer driver IC. Its primary function is to generate isolated +18 V and –5 V bias power up to 2 W for SiC MOSFET and IGBT gate drivers used in traction and industrial inverters. It supports both onboard pre-regulation and direct 15.6 V external input, enabling rapid validation of isolated bias supply topologies.

Can the UCC25800EVM-037 operate without the pre-regulator section?

Yes, the UCC25800EVM-037 can operate without the pre-regulator section. When using an external 15.6 V DC source, users connect it directly to J1 (+) and J2 (–) or terminal P1, and must remove resistor R23 to isolate the pre-regulator output. In this configuration, the LLC board alone delivers +18 V and –5 V outputs with 82.8% peak efficiency at full load.

What are the key electrical performance metrics of the UCC25800EVM-037?

Key metrics include input range (6–26 V), dual outputs (+18.10 V ±0.17 V and –4.98 V ±0.04 V), 2 W max output power, 500 kHz LLC switching frequency, 82.8% peak efficiency at 15.6 V input, <55 °C max board temperature at full load, and pass-level CISPR-25 Class-5 conducted EMI performance. Load regulation is ±1.0% across 0–85 mA output current.

How is synchronization implemented on the UCC25800EVM-037?

Synchronization is implemented via the SYNC pin (TP10) on the UCC25800EVM-037. Applying an external clock signal allows locking the LLC switching frequency - e.g., 577 kHz when driven by a 1.155 MHz input - enabling system-level timing coordination and EMI reduction. Without external sync, the default operating frequency is 497 kHz, as measured at the switch-node.

Does the UCC25800EVM-037 support over-current protection and fault reporting?

Yes, the UCC25800EVM-037 supports over-current protection with a 100 mA limit and fault reporting through the FLT pin (TP9). During over-current events, the FLT pin asserts low, providing a diagnostic signal for system monitoring. This functionality is validated in Section 6.11 of the user's guide, including oscilloscope waveforms showing switch-node voltage and primary current during fault conditions.