Patent ID: 6927641

Claim:
An oscillator including an oscillation circuit for outputting a signal having an oscillation waveform at a predetermined frequency, and an output driving device for receiving the signal having the oscillation waveform and outputting a clock signal having an output waveform with desired waveform characteristics, the output driving device comprising: a storing device for storing control data that adjusts waveform characteristics of the output waveform; a controlling device for extracting the control data stored in the storing device and outputting the control data for adjusting the waveform characteristics of the output waveform; a voltage controlling device for generating and outputting, upon input of a first power-supply voltage, a second power-supply voltage that defines an output amplitude of the output waveform in accordance with the control data; and a buffer circuit for adjusting, upon input of the signal having the oscillation waveform and the second power-supply voltage, the waveform characteristics of the output waveform in accordance with the control data, and outputting a clock signal; comprises: an output device for outputting, upon input of the signal having the oscillation waveform and the second power-supply voltage, the clock signal having an adjusted output amplitude of the output waveform; a plurality of driving-ability adjusting devices for adjusting, upon input of the signal having the oscillation waveform and the second power-supply voltage, the waveform characteristics of the output waveform in accordance with the control data, and outputting clock signals; and a switching device for selecting the clock signals output from the corresponding driving-ability adjusting device, in accordance with the control data; wherein, the switching device is operated in accordance with the control data to adjust the waveform characteristics of the output waveform.