A Fast Frequency Stable Voltage Controlled Oscillator

Abstract

The invention relates to a quick frequency stabilization voltage-controlled oscillator. The quick frequency stabilization voltage-controlled oscillator comprises a VCO (voltage-controlled oscillator) circuit module and a variable-capacitance array, and the VCO circuit module and the variable-capacitance array are in parallel connection. Parallel connection points of the VCO circuit module and the variable-capacitance array are connected with positive and negative output ends VOUT+ and VOUT- of the voltage-controlled oscillator respectively, the VCO circuit module is respectively connected with a signal output end of a pre-level charge pump and a VDD (voltage drain drain), and the variable-capacitance array is further connected with a filter capacitor and a digital DWA (data weighted average) modulation module which controls operating states of the variable-capacitance array. By application of the data weighted average technology to the variable-capacitance array of the voltage-controlled oscillator according to the technical scheme, array device mismatch noise caused by technical, temperature and voltage changes can be weakened, frequency band selection accuracy is improved, and clock period for frequency fine tuning is shortened. In addition, compared with a traditional VCO without adoption of a digital correction algorithm, the quick frequency stabilization voltage-controlled oscillator has the advantage of short frequency stabilization time.

Description

technical field [0001] The invention relates to the field of phase-locked loop frequency synthesizers, in particular to a fast frequency stable voltage-controlled oscillator. Background technique [0002] In the existing phase-locked loop frequency synthesizer, the frequency stabilization of the voltage-controlled oscillator (VCO) is accomplished through two steps: frequency band selection and loop fine-tuning. The frequency band selection is realized by adjusting the variable capacitor array according to the value of the digital baseband control signal, which mainly completes the coarse adjustment function of the frequency; after the frequency band is selected, the phase-locked loop provides The frequency of the voltage signal is fine-tuned, and finally the frequency lock of the entire frequency synthesizer is completed. However, due to changes in technology, temperature and voltage, the capacitive devices in the variable capacitive array used for frequency band selection ...

AI Technical Summary

Problems solved by technology

However, due to changes in process, temperature and voltage, the capacitive devices in the variable capacitive array used for frequency band selection will have errors from the ideal value, or there will be matching errors in the array devices

This error will cause the selected frequency band to deviate from the ideal frequency band, which needs to be compensated by the frequency trimming part, thus requiring more trimming cycles and prolonging the lock time of the frequency synthesizer

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