Power factor controller provides low harmonic distortion and maximum efficiency

April 15, 2013 // By Graham Prophet
Intersil's latest PFC controller chip operates over wide voltage ranges and employs a negative capacitance technology; use it for AC/DC Adaptor and power supply applications

An active power factor controller that delivers minimal harmonic distortion (THD) and high power factor (PF) correction, the ISL6730A features negative capacitance technology which reduces EMI filter size, improves THD and PF and provides maximum efficiency over a wide input supply range and output power (input voltages from 85VAC to 270VAC and power range from 50W to 2 kW). This technology also minimises zero crossing distortion, compensates for input filter capacitance PF displacement error and reduces magnetic component size by up to 66%. For example, in an 85-W power supply the EMI filter inductor can be reduced from 150 µH to 56 µH. The small external components result in a lower cost design with improved performance.

The device’s power factor correction capability is compatible with the requirements for a power factor higher than 0.9, as currently required by the US Energy Star Program Requirements for Computers Version 5.0. The IC also achieves good light-load efficiency using integrated skip-mode, and includes an internally clamped 12.5-V gate driver delivering 1.5A peak current to the external power MOSFET.

The ISL6730A enables a reliable system that is fully protected with features such as cycle-by-cycle over-current, power limiter, over-temperature, input brownout, output over-voltage and under-voltage protection. In a 10-lead MSOP package it costs from $0.95 (1,000).

More information here.