LLC Resonant converter control card reference design
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.

Description & Features

Technical documentation

Support & Training

Order Now

See the Important Notice and Disclaimer covering reference designs and other TI resources.

Key Document


This reference design is a control card for an LLC converter and integrates all of the essential functions for controlling an LLC converter, including the HV start-up, X-capacitor discharge and the drivers for the power FETs. By employing the advanced burst mode, it can also help the LLC converter achieve ultra-low standby power even with PFC on. This design is flexible to evaluate and is suitable for any power rating of an LLC power board. It is easy to set up a bench test with an existing power stage with simple connections. 

  • Single-chip solution with essential functions for LLC
  • Integrated HV startup and driver
  • Best-in-class load and line transition response
  • Low standby power consumption
  • X-cap discharge

See the Important Notice and Disclaimer covering reference designs and other TI resources.


Schematic/Block Diagram

Quickly understand overall system functionality.

Download Schematic

Design Guide

Get results faster with test and simulation data that's been verified.

Download Design Guide

Design Files

Download ready-to-use system files to speed your design process. Get Viewer.

Download Design Files

(Output Voltage 1)
Vin (Min) (V)90
Vin (Max) (V)264
Vout (Nom) (V)24
Iout (Max) (A)14
Output Power (W)336
Input TypeAC
TopologyBoost- PFC
Half Bridge- Resonant

TI Devices (1)

Order samples, get tools and find more information on the TI products in this reference design.

Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
UCC256404  LLC resonant controller with ultra-low power, ultra-quiet standby operation and high voltage startup  Offline & isolated DC/DC controllers & converters  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
UCC256404 Download Download

Texas Instruments and Accelerated Designs, Inc. have collaborated together to provide TI customers with schematic symbols and PCB layout footprints for TI products.

Step 1: Download and install the free download.

Step 2: Download the Symbol and Footprint from the CAD.bxl file table.

Technical documentation

See the Important Notice and Disclaimer covering reference designs and other TI resources.

User guide (1)
Title Type Size (KB) Date
PDF 992 26 Jun 2019
Design files (6)
Title Type Size (KB) Date
ZIP 482 26 Jun 2019
ZIP 1653 26 Jun 2019
PDF 343 26 Jun 2019
PDF 169 26 Jun 2019
PDF 93 26 Jun 2019
PDF 105 26 Jun 2019

Support & training

TI E2E™ forums with technical support from TI engineers

Search our extensive online knowledge base where millions of technical questions and answers are available 24/7.

Search answers from TI experts

Content is provided 'AS IS' by the respective TI and Community contributors and does not constitute TI specifications.
See terms of use.

If you have questions about quality, packaging, or ordering TI products visit our Support page.

Technical articles