VCO

Abstract

The invention discloses a voltage-controlled oscillator comprising a control voltage gain circuit and a ring oscillation circuit; the control voltage gain circuit comprises a first NMOS tube and a cascode current mirror circuit connected by a common source, and the source of the first NMOS tube passes through The first resistor is grounded and implements source degeneration. The cascode current mirror circuit outputs the control voltage amplified signal, which is input to the control terminal of the ring oscillation circuit and used to control the output frequency of the ring oscillation circuit. The invention can improve the linearity of the circuit and reduce the power consumption of the circuit, can improve the quality of the clock signal and guarantee the stability of the system.

Description

technical field [0001] The present invention relates to a semiconductor integrated circuit, in particular to a voltage-controlled oscillator (VCO). Background technique [0002] Although VCO and phase-locked loop technologies have been proposed for nearly 100 years, they are widely used in electronic systems, and the requirements for performance are getting higher and higher. The current PLL chip is developing in the direction of high frequency, wide frequency bandwidth, large integration, low power consumption, low price, and powerful functions. Among them, the design of the core unit VCO is very important. The main problem faced by the current VCO design is the adjustment range. Limitations: The center frequency of some CMOS oscillators may vary by a factor of two under extreme process and temperature variations, and limitations in the adjustment range may render them non-functional. Adjustment linearity: nonlinearity degrades the stability of the phase-locked loop but as...

AI Technical Summary

Problems solved by technology

The current PLL chip is developing in the direction of high frequency, wide frequency bandwidth, large integration, low power consumption, low price, and powerful functions. Among them, the design of the core unit VCO is very important. The main problem faced by the current VCO design is the adjustment range. Limitations: The center frequency of some CMOS oscillators may vary by a factor of two under extreme process and temperature variations, and limitations in the adjustment range may render them non-functional

Adjusting linearity: nonlinearity degrades the stability of the phase-locked loop but as the operating frequency becomes higher and higher

Excessive power consumption seriously affects its range of use

Images