Marvell has announced new digital power technology to lower PC and notebook power consumption. The company supplies OEMS making PC and notebook power supplies.

Marvell spokesperson Linda Sanders said: "Overall the power savings could vary from 35 to 50 percent depending on how the computer is being used."

The new chips are DSPs (digital signal processors), which dynamically adapt power characteristics in real time for power supplies and power adapters for PCs and notebook computers, by better controlling the AC-DC current switching needed.

The digitalisation of power supplies has been talked about for some time.

Digital signal processing involves digitising an input analogue signal, such as a sound stream, modifying its digital profile in real time to produce a desired characteristic, such as enhanced bass notes, and then feeding the modified sound stream to a device, such as a loudspeaker, and producing a better outcome.

With Marvell's power factor correction (PFC) technology, incoming electric current to a PC or notebook has its profile modified through a DSP chip. It determines the amount of power required for users’ applications that keeps the peak current at the lowest level, improving energy efficiency.

It does this with an adaptive drive capability which intelligently adjusts the electricity supply profile to reduce power supply switching losses and also reduces electro-magnetic interference.

Voltage and current are brought into phase; they arrive in separate waves, wasting less energy than present technology. Sanders said: "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."

Adaptive current limits are also automatically adjusted for varying current threshold limits worldwide, which adds system protection and reliability.

Marvell-based notebook adapters are approximately one-third smaller and lighter than current notebook adapters. This is because the new components can replace up to 20 individual parts used currently and so simplify power supply design as well as increasing power efficiency.

Sanders said: "Notebook and desktop PC vendors source power supplies from other vendors rather than building them directly. We are working with several power supply vendors who are based in Asia." In effect: "We're working with all the leading PC vendors as we supply a range of components including storage, networking and Wi-Fi chips."

Larry Qua, chairman and CEO at Ionics EMS, a supplier of IT power equipment to computer manufacturers, said: “With more functionality integrated onto a single chip, we can build our power supplies with fewer components thus saving cost and reducing design and manufacturing complexity. We are using Marvell’s chips to build energy-efficient notebook adapters as well as power supplies for applications such as flat-screen TVs and printers.”

The US Environmental Protection Agency (EPA) estimates that there are more than 10 billion AC-DC power supplies used in computing, telecommunications, and consumer electronics world-wide. According to the EPA, more efficient power supply designs could significantly reduce US energy use, saving nearly $3 billion and about 24 million tons of carbon dioxide emissions per year.

The US Energy Star rating system for PCs mandates that AC power efficiency has to reach 80 percent. By reducing the proportion of wasted energy at the power input stage the rest of a computer's components have less individual work to do to increase the computer's overall power efficiency.

Marvell's 88EM8041 controller chip for notebook adapters and 88EM8011 controller chip for desktop power supplies are in production now with volume ramp anticipated for Q1’08.