LLC resonant controller achieves 90 percent efficiency with a 10 percent load

The first in a family of new high-performance LLC controllers, TI’s new UCC256301 inductor-inductor-capacitor (LLC) resonant controller enables standby power of less than 40 mW when fully regulating the system output, while also performing better than industry efficiency requirements. By delivering the fastest transient response plus robust fault-protection features such as zero current switching avoidance, the device enables reliable operation over end-equipment lifetimes.

The device includes an integrated high-voltage gate driver that enables the industry’s lowest standby power, as well as longer system lifetimes. The UCC256301 provides a cost-effective system solution that helps meet stringent energy-efficiency standards for a wide range of AC/DC applications, including digital televisions, gaming adapters, desktop computer and notebook adapters, and power-tool battery chargers.

“The consumer electronics market demands efficient power supplies with low standby power. With this new family of LLC controllers, TI is enabling designers to do more with less power,” said Steve Lambouses, TI vice president, High Voltage Power. “The UCC256301 was designed to meet tomorrow’s power requirements by delivering breakthroughs in standby power and efficiency while simplifying design and lowering system cost.”

Key features and benefits of the UCC256301

• High efficiency and lowest standby power: By achieving a new low in standby power, the controller exceeds Code of Conduct (CoC) Tier 2 and U.S. Department of Energy (DoE) Level VI efficiency standards and achieves more than 90 percent efficiency with a 10 percent load.
• Faster and more stable system transient performance: Hybrid hysteretic control, a new patented control method from TI, enables up to 10 times faster transient response and reduces output capacitance by 20 percent, leading to faster system response times.
• Extended system lifetime: Robust fault-protection features on the device, such as zero current switching avoidance, extend system lifetimes.
• Simplified design: Engineers can easily design their systems with the integrated X-capacitor discharge and high-voltage startup features. 

 

The UCC256301 is the latest addition to TI’s high-voltage portfolio of end-to-end power-conversion solutions delivering high efficiency. In addition to the UCC256301, the new portfolio of LLC controllers includes the UCC256303, which works easily with an external bias, and the UCC256304, which supports wide input ranges.

Engineers can pair the UCC256301 with a TI power factor correction (PFC) controller and synchronous rectifier (SR) controller to increase system efficiency. To meet a variety of power levels, PFC controllers include the UCC28180, UCC28063, UCC28051 and UCC28070. The UCC24610 SR controller can also be paired with the UCC256301 to further improve efficiency.

 

Support tools for the UCC256301 to speed engineers’ time to market include the UCC25630-1EVM-291 evaluation module, WEBENCH® Power Designer and SIMPLIS transient models. Engineers can jump-start high-voltage system designs using the UCC256301 with the  480W AC/DC Industrial Reference Design and 450W AC/DC Reference Design with Single-Layer PCB.

 

The UCC256301 is now available in the TI store and through the company’s authorized distribution network. This LLC controller comes in a small-outline integrated circuit (SOIC)-16 package and is priced at US$0.99 in 1,000-unit quantities.