.20 Mhzcmos Process Low-power Low Phase Noise Quartz Crystal Oscillator Design,

Crystal oscillator is an integral part of radio frequency (RF) and digital devices. With the high Q of an electromechanical quartz crystal as the frequency-selecting component, the crystal oscillator has very high frequency stability and low phase noise providing very accuracy clock signal reference. The paper is concerned with the condition of reliable start-up of the oscillation, the automatic gain-controlled feedback loop and the phase noise is discussed in this paper in order to get all the design guides for high stability, low power dissipation and low phase noise. Based on these design guides, the analysis and design of a low phase noise and low power dissipation 0.35μm CMOS process integrated Colpitts crystal oscillator with automatic gain-controlled feedback loop as the amplitude-limiting technique is performed. The oscillation with very stable amplitude value is achieved under the condition of wide range of power supply voltage (2.7V-5V) and working temperature (-40℃-125℃) and process changing. As the oscillation circuit dissipation is proportional to the oscillation signal amplitude, the controlled oscillation signal amplitude make sure of the low oscillation circuit dissipation. Special layout design technique is applied to prevent the circuit failure from Latch-up, electrostatic discharge (ESD), substrate noise and power line noise. The Crystal oscillator is fabricated in a 0.5μm n-well double-poly double-metal CMOS process together with phase-locked loop circuit, MCD8825B, on a single chip as the reference clock-signal generator. Based on simple circuit model, the rough value of oscillator circuit component is achieved. Further, by taking the advantages of EDA circuit design software such as Matlab, Advanced Design System (ADS) and Spectral in Cadence, the accurate value of oscillator circuit...