Semiconductor manufacturer Marvell has developed power supply technology designed to cut PC energy use and help decrease carbon emissions.

The digital power factor correction technology is based on Marvell's digital signal processing and power management systems.

The chips dynamically adapt the incoming electrical current and align the current and voltage coming from the outlet for optimal energy use by the PC.

This improves the energy efficiency of the power supply and reduces electro-magnetic interference by intelligently adjusting the supply profile to provide only the amount of power required by the PC at any given time.

"Being out of phase generates a lot of heat as you may know if you've ever picked up your notebook adapter after it's been running awhile," said Linda Sanders, a spokeswoman for Marvell.

Today, more than half the power from the outlet is wasted as heat, but Sanders claims that the new design allows power savings of 35 to 50 per cent depending on how the computer is being used.

The US Environmental Protection Agency estimates that there are more than 10 billion AC-DC power supplies used in computing, telecoms and consumer electronics worldwide.

More efficient power supply designs could significantly reduce US energy use by about 24 million tonnes of carbon dioxide emissions per year, saving nearly $3bn annually.

"Marvell is committed to green technology that will reduce our collective carbon footprint and slow the rate of climate change," said Hubie Notohamiprodjo, general manager of industrial control and power management at Marvell.

"As a supplier and user of energy efficient technology, and a sponsor of the Climate Savers Computing Initiative, we are developing products that will save energy in electronic devices as well as implementing energy savings in our facilities."

Marvell's smart energy efficient technology could be used in internal and external power supplies for a wide range of consumer electronics including flat-screen TVs, home entertainment products and portable devices.

The DSP-based AC-DC controller chips also allow power supply manufacturers to eliminate up to 20 discrete components.

This should help reduce design complexity, increase reliability and drive down manufacturing costs, as well as slim down today's notebook adapter bricks in weight and size.

The Marvell 88EM8041 controller chip for notebook adapters and the Marvell 88EM8011 controller chip for desktop power supplies are in production now with volume production anticipated for the first quarter of 2008.