Phase-shifted PWM controller meets high efficiency standards

Texas Instruments Inc. introduces a phase-shifted full-bridge PWM controller with synchronous MOSFET control outputs and light load power management. The UCC28950 can achieve efficiencies above 90% from light load to full load, enabling it to meet 90+ Climate Savers efficiency standards. The device features a 10:1 wide range adaptive zero voltage switching (ZVS) control scheme. The wider ZVS operational range directly translates into reduced energy consumption across a wider power output range.

The UCC28950 also has optimized adaptive control for the output synchronous rectifiers including on/off control to optimize efficiency at lighter loads. The UCC28950 is designed for applications such as high-power, high-density power supplies; server and telecom power supplies; industrial power systems; solar inverters; electric vehicles; and dc motor drives.

Key features and benefits of the UCC28950 include:
· Synchronous rectifier outputs with optimized timing minimize body diode conduction losses from typical propagation delays, which ensure high efficiency.
· UCC28950 features advanced power management functions that change operational modes under different start-up or load conditions and a burst mode that improves light load or no load efficiency by as much as 70% compared to non-green mode solutions. The UCC28950’s programmable ramp compensation allows for current or voltage mode control, adding system flexibility.
· A soft start with enable function allows the UCC28950 to initialize start-up by higher-level system control.
· Sync in and sync out function with 90° phase shift for interleaved operation of two parallel power supplies reduces input and output ripple current by 50 to 100%. This lower input and output ripple current allows designers to use smaller, lower-cost input and output capacitors.

For more information, contact Texas Instruments Inc., 12500 TI Blvd., Dallas, TX 75243. Phone: (972) 644-5580.