CMOS current automatic control crystal oscillator

Abstract

The invention relates to a CMOS current automatic control Colpittis crystal oscillator, comprising an oscillation circuit, an amplitude detection circuit, an automatic gain control circuit, a current source and a level detection unit; wherein the current source provides bias current for the oscillation circuit, the oscillation circuit generates an oscillation signal to be sent to the amplitude detection circuit for amplitude detection, the detection output is sent to the automatic gain control circuit for gain adjustment, and the output after adjustment is fed back to the current source for regulating the bias current. The increase and decrease of the bias current change the oscillation amplitude, while the change of the amplitude regulates the bias current by detection and gain adjustment. The oscillation signal of the oscillation circuit is also sent to the level detection unit, an output signal of which controls the on and off of the current source and the automatic gain control circuit. The crystal oscillator can cause the oscillation circuit to establish oscillation rapidly and uses a feedback circuit to fast regulate bias after the generation of oscillation, thus leading theoscillation circuit to be stabilized in the minimum current state for maintaining oscillation.

Description

technical field [0001] The invention relates to a current automatic control Colpittis crystal oscillator of CMOS technology. Background technique [0002] Oscillators are an essential part of many electronic products, and crystal oscillators occupy an important position in the field of electronic technology due to their high precision and high frequency stability. In particular, the rapid development of the information technology (IT) industry has made crystal oscillators full of vitality. Crystal oscillators are used as standard frequency sources or pulse signal sources in communication systems, mobile phone systems, global positioning systems (GPS), navigation, remote control, aerospace, high-speed computers, precision measuring instruments, and consumer electronics products. The frequency reference cannot be replaced by other types of oscillators at present. The crystal oscillator relies on the piezoelectric characteristics of the crystal, active excitation and passive ...

AI Technical Summary

Problems solved by technology

However, in terms of oscillation establishment, the Colpittis oscillator is not easy to start-up compared to the Pierce oscillator, the start-up time is longer, and the power consumption is also larger

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