Title: Method and apparatus for selectively increasing the operating speed of an electronic circuit
Type: issued patent
Patent number: 7,171,570
Issue date: January 30, 2007
Filing date: May 3, 2004 (priority to November 16, 2001)
Link to PDF: 
AIPW Summary: A circuit begins operating in a low power state. If more performance is needed, the circuit enters a first intermediate power state (a slightly higher power level). Higher power levels, such as a maximum sustainable power level and a boosted power level, are possible. This arrangement permits power conservation and minimizes the requirements for heat dissipation. The time spent in the each power level can be limited. Increases to higher power levels may be limited based on the amount of heat currently being generated; if a heat threshold is exceeded, the circuit may not go to a higher power level.
