Parallel-connection type crystal oscillator

Abstract

The invention discloses a parallel-connection type crystal oscillator comprising a power supply positive electrode input end, a power supply negative electrode output end, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first inductor, a second inductor, a third inductor, a first transistor, a second transistor and a crystal oscillator. A power supply filter circuit can be improved, and control of output signal DC level can be realized so that DC level outputting a sinusoidal signal is constantly ensured to be biased at the preset value in the oscillation process of the crystal oscillator, system stability is guaranteed, ripple voltage is reduced and a DC component is enhanced.

Description

technical field [0001] The invention relates to a crystal oscillator, in particular to a parallel crystal oscillator. Background technique [0002] As a basic circuit module, the crystal oscillator circuit is used in the chip to generate a precise clock signal. This clock signal can not only be mixed with the signal after frequency conversion to realize modulation and demodulation; it can also be used as a reference clock for digital modules. Therefore, crystal oscillators exist in almost every chip and have extremely wide applications. [0003] It takes a relatively long time to start the crystal oscillator (low-frequency crystal oscillators usually need hundreds of milliseconds or even seconds). Generally speaking, increasing the current means increasing the power consumption will shorten the start-up time, but at the same time it will increase the amplitude of the signal after the start-up. For the crystal oscillator circuit, if the output signal amplitude is too large...

AI Technical Summary

Problems solved by technology

Generally speaking, increasing the current means increasing the power consumption will shorten the start-up time, but at the same time it will increase the amplitude of the signal after the start-up

For the crystal oscillator circuit, if the output signal amplitude is too large, it will not only cause waveform distortion, but also generate too many harmonics, which will affect the performance of the output signal, and the excessive oscillation amplitude will seriously affect the life of the crystal, even Damaged crystal oscillator

In addition, in order to meet the fluctuation of crystal parameters and crystal oscillators of different frequencies, if a fixed current is used to drive the circuit, some crystal oscillators will not vibrate, and some crystal oscillators will have too large amplitude.

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