Annular high-speed voltage-controlled oscillator

Abstract

The invention discloses an annular high-speed voltage-controlled oscillator. The annular high-speed voltage-controlled oscillator is formed by series connection of four levels of delay units, wherein the negative output end (Vout-) of each level of delay unit is connected with the positive input end (Vin+) of a corresponding next level of delay unit, the positive output end (Vout+) of each level of delay unit is connected with the negative input end (Vin-) of a corresponding next level of delay unit, the negative output end (Vout-) of the last level of delay unit is connected with the negative input end (Vin-) of the first level of delay unit, and the positive output end (Vout+) the last level of delay unit is connected with the positive input end (Vin+) of the first level of delay unit. According to the annular high-speed voltage-controlled oscillator, an active electrical inductance structure is additionally arranged based on traditional delay units, a pair of PMOS tubes with grid electrodes connected to the ground are additionally arranged at a load end, therefore, oscillation of a circuit within the whole voltage range is guaranteed, extra electric currents can be provided for the circuit, and the oscillation frequency is improved; a control voltage is connected to the grid electrodes of the pair of PMOS tubes so that the frequency of the delay units can be controlled, and the PMOS tubes serve as voltage-controlled resistors and are used for adjusting the oscillating frequency.

Description

technical field [0001] The invention belongs to the field of semiconductor integrated circuit design, and mainly relates to a ring voltage-controlled oscillator with high speed and high tuning linearity. Background technique [0002] A voltage-controlled oscillator (Voltage-Controlled-Oscillator, VCO) is a signal source whose frequency varies with voltage. It is widely used in phase-locked loops, clock recovery and frequency synthesis circuits, and is a key component of these circuits. In integrated circuits, voltage-controlled oscillators can be divided into two categories: ring oscillators and inductor-capacitor oscillators. The noise performance of the LC oscillator is better, but it requires an additional process to integrate the inductor and occupies a larger area. The ring oscillator can be realized by standard CMOS technology, relatively small in area, and has a wide tuning range, which is suitable for system-on-chip. [0003] Ring oscillators can be divided into t...

AI Technical Summary

Problems solved by technology

[0005] Purpose of the invention: Aiming at the problems and deficiencies of the existing ring voltage-controlled oscillator, the purpose of the invention is to provide a ring voltage-controlled oscillator with high speed and high tuning linearity device

Images