CMOS oscillator

Abstract

The invention, which belongs to the technical field of the analogue integrated circuit, particularly relates to a CMOS oscillator. According to the invention, the pumping characteristic of the capacitor is used and the traditional resistor-capacitor charging and discharging process is replaced; and a way of combination of level conversion with capacitor pumping is employed and the high-speed oscillator characteristic is realized easily. The circuit structure is simple; and the traditional oscillator circuit area with the operational amplifier is reduced and the cost is lowered. Meanwhile, a bistable circuit is introduced and is combined with a level conversion circuit. On the basis of the characteristic of low delay of the level conversion circuit, the response can be started rapidly when the power is on, thereby substantially shortening the starting time of the oscillator. The provided scheme is especially suitable for a high-frequency CMOS oscillator.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and in particular relates to a CMOS oscillator. Background technique [0002] Oscillator (English: Oscillator), referred to as OSC, is an electronic device used to generate repetitive electronic signals (usually sine waves or rectangular waves). The various oscillating signals generated by it can provide various timing, switch control and signal Various modulations, etc., have become key functional modules in analog and digital circuit systems, and have an important impact on the performance of digital and analog signal processing. With the maturity of semiconductor CMOS technology, CMOS oscillators develop rapidly and gradually replace traditional oscillators. [0003] Oscillators are mainly divided into RC oscillators, LC oscillators, and crystal oscillators according to different circuit structures. figure 1 Shown is a traditional RC oscillator structure block diagram, inc...

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Problems solved by technology

[0004] Traditional RC oscillators are widely used, but there are also some disadvantages: since there are two flipping voltages V1 and V2 in the circuit, the circuit needs two operational amplifiers A1 and A2 as comparators, which will increase the circuit The area and cost increase the complexity of the circuit structure, and the difference in the offset voltage of the two comparators will cause the deviation of the oscillator output frequency

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