Transmeta has licensed its LongRun2 power management technology to Fujitsu, the second customer to purchase the rights to use the technology, Transmeta said Thursday.
LongRun2 is an improvement to an earlier Transmeta technology that managed transistor frequency depending on an application's workload in order to maximize power consumption. This helps to control power consumption when the transistor is active but does not address the growing problem of power leakage when the transistor is inactive.
The ever-shrinking size of transistors has exacerbated the problem of current leakage. Transistors now are so small that current can escape through the transistor even when it is not actively flowing through the transistor. This problem is known as passive or standby leakage, and it is expected to become even worse in the future.
LongRun2 specifically targets passive leakage by controlling the threshold voltage of the transistor. The threshold voltage is the amount of power required to turn the transistor on or off.
Other power management technologies must raise or lower the threshold voltage in step with changes in frequency. This means that when frequency is reduced because the transistor is idle, the threshold voltage is scaled down to a point where very low levels of current can activate the transistor and cause power to leak out of it. Transmeta's LongRun2 technology prevents this by setting the threshold voltage high enough to prevent an idle transistor from turning on inadvertently in the presence of small amounts of power.
NEC Electronics was the first company to sign a license for the technology, which is also found in the 90-nanometer version of Transmeta's Efficeon processors. Financial terms of both deals have not been disclosed.
Transmeta and Fujitsu have close ties. Transmeta is using Fujitsu as a foundry for its 90-nanometer Efficeon processors, and Fujitsu uses Transmeta processors in some of its notebooks and Tablet PCs.
Despite the improved performance of its Efficeon processors, Transmeta is still having a tough time getting its chips into ultraportable notebooks outside of the Japanese market. According to a filing with the U.S. Securities and Exchange Commission earlier this year, Transmeta might be forced to shift the focus of its business from processor design to technology licensing if the company continues to lose money.