Loop oscillator circuit similar to phase-locked loop

Abstract

The invention discloses a loop oscillator circuit like a phase-locked loop. The loop oscillator circuit comprises a voltage generation circuit; a voltage comparison circuit, wherein the negative input end of the voltage comparison circuit is connected with the first output end of the voltage generation circuit, and the output end is connected with the input end of a voltage-to-current module; an oscillator, wherein the input end of the oscillator is connected with the output end of the voltage-to-current module and the second output end of the voltage generation circuit; a current-to-voltage module which is connected in parallel between the output end of the voltage-to-current module and the input end of the oscillator; and a filter circuit, wherein the input end of the filter circuit is connected between the two output side inverters of the oscillator, and the output end of the filter circuit is connected to the positive input end of the voltage comparison circuit. On the premise that no external reference frequency is input, the output frequency of the chip is still kept stable, and the circuit has the advantages of resisting power supply voltage, temperature and process fluctuation.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to a kind of phase-locked loop oscillator circuit. Background technique [0002] In the field of integrated circuit design, the frequency signal generation circuit is at the very core. The frequency signal generation circuit is used to provide the most basic frequency signal to other modules on the circuit board. The frequency signal generation circuit includes the following two structures, one is a phase-locked loop circuit, and the other is an oscillator circuit. The internal structure of the phase-locked loop circuit is complex, and it has a frequency feedback loop, such as figure 1 shown. The traditional phase-locked loop circuit includes a frequency detector PFD, a current source I1, a PMOS transistor P1, an NMOS transistor N1, a current source I2, a capacitor C1, a resistor R1, a capacitor C2, a voltage-controlled oscillator VCO and a frequency divider FP. The powe...

AI Technical Summary

Problems solved by technology

However, it is very easy to get out of control during the locking process, resulting in a decrease in the chip yield, and cannot solve the problems caused by process fluctuations, making it unusable in application backgrounds that require high frequency signal stability.

[0004] To sum up, in the application background where there is no reference frequency input and the output frequency is required to be stable, it is difficult for the traditional frequency signal generation circuit to solve the problem that the output frequency of the oscillator chip is resistant to voltage and frequency process fluctuations

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