Power management chip boosts energy efficiency

Texas Instruments Inc. introduces what it claims as the industry's first single-chip, interleaved power factor correction (PFC) control circuit for multi-kilowatt communications, server and industrial systems. The UCC28070 two-phase, average current-mode controller allows designers to simplify power design, increase system reliability and achieve a greater than 0.9 power factor rating, which improves energy efficiency.

In line-operated systems with power levels from 75 W to 1kW and above, the UCC28070 helps reduce total harmonic distortion, allowing today's systems to better maximize usable outlet power and accommodate extreme variations and disturbances in various AC line voltage levels used around the world.

According to TI, the device helps increase system reliability by incorporating a unique 180° interleaving method, which reduces the amount of input and output current ripple and distributes the magnetics to improve thermal management. Average current mode interleaving allows a system to achieve between 50 and 100 percent reduction in ripple compared to today's typical non-interleaved PFC architectures.

The UCC28070's optional programmable-frequency dithering mode allows a designer to spread the switching frequency over a range to minimize the generation of electromagnetic interference (EMI). The dithering feature helps reduce capacitor size and enables the use of a smaller, less expensive EMI filter.

The UCC28070 offers several unique system control and protection features to improve overall system reliability. An output over-voltage protection scheme with an open-loop detection feature safeguards the system from common circuit board failures. Each phase current is accurately balanced with independent current sensing to prevent excess component heating in the device's dual-phase operation. In addition, the UCC28070 provides under-voltage lockout, cycle-by-cycle peak current limit, and a system over-temperature protection feature.