TI's new green phase-shifted full-bridge controller includes synchronous rectifier output control

DALLAS, USA: Texas Instruments Inc. (TI) has introduced a phase-shifted full-bridge PWM controller with synchronous MOSFET control outputs and light load power management.

The UCC28950 can achieve efficiencies above 90 percent from light load to full load, enabling it to meet 90+ Climate Savers efficiency standards. The device features an adaptive zero voltage switching (ZVS) control scheme with a 10:1 range that can maintain ZVS over wide input voltage variations or output load swings. The wider ZVS operational range saves energy consumption across a broader 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 like 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
* Synchronous rectifier outputs optimize timing to 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 percent 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 degrees phase shift for interleaved operation of two parallel power supplies reduces input and output ripple current by 50 to 100 percent. This lower input and output ripple current allows designers to use smaller, lower-cost input and output capacitors.

The UCC28950 is available now in a TSSOP-24 package and is priced at $4.25 in quantities of 1,000.