A novel CMOS current-steering amplifier based ring oscillator with the waveform shaping circuit

Oscillator is a major part of many electronic systems. Its applications are from microprocessor clock generation to the nest bee phone carrier synthesis. This paper describes a voltage controlled ring oscillator used in ICs as inner clock source, and uses a three-stage current-steering amplifier (CSA) structure as the oscillation circuit. This VCO circuit has many advantages, such as simple structure, high operating frequency, good linearity relationship between controlling voltage and frequency, and wide frequency band. The oscillator circuit is simulated with Singapore´s Chartered Company 0.35μm N-well mixed signal CMOS process by Hspice software. Signals with good waveform and tuning frequency from 3~625MHz are obtained. The circuit is easy to be integrated and with low power consumption.