Patent ID: 7449961

Claim:
An oscillator, comprising: a plurality of oscillating units connected in parallel with each other; and a control unit which controls number of parallel connections of said plurality of oscillating units based on an instruction signal indicating accuracy to be tolerated with respect to oscillation outputs of said oscillating units, wherein said plurality of the oscillating units include: a first loop oscillating unit formed by connecting a plurality of first inverters in series in multiple stages, the first loop oscillating unit outputting an oscillation signal; and a second loop oscillating unit formed by connecting a plurality of second inverters in series in multiple stages, the second loop oscillating unit being connected in parallel with the first loop oscillating unit to improve the accuracy of the oscillation signal, and wherein said control unit turns on/off connection between an output path of any one of the plurality of second inverters and an output path of the first inverter in a stage corresponding to the second inverter among the plurality of first inverters based on the instruction signal.