A LC voltage-controlled oscillator with automatic correction of output swing

Abstract

The invention relates to an LC voltage-controlled oscillator with an automatic output oscillation amplitude correction function. The LC voltage-controlled oscillator comprises an oscillator core circuit module, a low-pass filtering device, a comparator, a digital automatic amplitude correction module, a biasing circuit module and a switch resistor control word generation module. The oscillator core circuit module comprises a first switch resistor array, an LC resonance network, a variable capacitor array / cross coupling transistor and a second switch resistor array. The biasing circuit module comprises a third switch resistor array and a current programmable control array. The LC voltage-controlled oscillator has the advantages that the switch resistor arrays are substituted for conventional current source arrays, so that influence of noise in circuits on phase noise of the oscillator is reduced; a biasing circuit is used for adjusting the output oscillation amplitude of the oscillator in real time, and an output amplitude detection loop is formed by the low-pass filtering device, the comparator and the digital automatic amplitude correction module; output signal amplitude detection points are selected between a resonance network and the switch resistor arrays, and accordingly, influence of detection loop noise on oscillator output signals is reduced.

Description

technical field [0001] The invention relates to the field of oscillators, in particular to an LC voltage-controlled oscillator with automatic output swing correction. Background technique [0002] The output swing of the previous voltage-controlled oscillator is controlled at a specific value through circuit design, or the tail current source array is used to dynamically adjust the output swing. Due to the influence of temperature drift, voltage and manufacturing process, the technology used in the former has a large deviation between the actual output swing and the ideal value, and the output swing cannot be adjusted, which eventually leads to the extremely poor and inability of the voltage controlled oscillator. Optimized phase noise performance; although the latter uses a current source array for dynamic output swing adjustment, the noise generated by the tail current source array will pass through the cross-coupled transistor and the inductor-capacitor resonant network i...

AI Technical Summary

Problems solved by technology

Due to the influence of temperature drift, voltage and manufacturing process, the technology used in the former has a large deviation between the actual output swing and the ideal value, and the output swing cannot be adjusted, which eventually leads to the extremely poor and incapable voltage controlled oscillator. Optimized phase noise performance; although the latter uses a current source array for dynamic output swing adjustment, the noise generated by the tail current source array will pass through the cross-coupled transistor and the inductor-capacitor resonant network in the voltage-controlled oscillator, and the oscillation The signal enters the output signal together, which seriously deteriorates the phase noise of the oscillator; at the same time, the swing detection point is selected at the position of the output signal, so that the noise in the detection circuit also enters the output signal, which seriously affects the quality of the oscillator output signal

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