Patent ID: 8112054

Claim:
A method of operating a system that includes a Phase Locked Loop (PLL) that controls a frequency of a radio, said radio only operating for short periods of time, said method comprising: at the beginning of a particular operating period of said radio, operating said PLL in a closed loop manner to stabilize an output frequency of said PLL; after the output frequency of said PLL has stabilized, tri-stating said PLL, wherein said PLL includes a capacitor that controls the output frequency of said PLL, a phase frequency detector and a charge pump, and wherein tri-stating said PLL comprises preventing charge from being added to and removed from said capacitor and tri-stating said phase frequency detector and said charge pump; preventing power from flowing to said phase frequency detector (PFD) and said charge pump of the PLL; and continuing to operate said tri-stated PLL for a remainder of said particular operating period to provide a frequency reference to said radio.