Segmented low-voltage control gain ring oscillator and tuning slope switching circuit

Abstract

The invention discloses a segmented low-voltage control gain ring oscillator. The segmented low-voltage control gain ring oscillator comprises a delay cascade circuit, a tuning slope switching circuit and an oscillation frequency segmented control circuit. The segmented low-voltage control gain ring oscillator is characterized in that the tuning slope switching circuit is used for switching tuning voltage, and the switched tuning voltage is output to the tuning voltage end of the delay cascade circuit so as to adjust delay time of cascade delay units. The oscillation frequency segmented control circuit receives external control signals, current signals of different magnitudes are output according to the external control signals, and the voltage across the tuning voltage end of the delay cascade circuit is adjusted. The delay cascade circuit is composed of the four levels of delay units, the tuning voltage ends of the four levels of delay units are connected together, and the tuning voltage output by the tuning slope switching circuit is received. The tuning slope switching circuit and the oscillation frequency segmented control circuit are combined, and the ring oscillator simultaneously achieves wide frequency covering and low-voltage control gain characteristics, and can be widely applied to a radio frequency phase-locked loop system.

Description

technical field [0001] The invention relates to a ring oscillator, in particular to a segmented low-voltage controlled gain ring oscillator and a tuning slope conversion circuit. Background technique [0002] As a key unit in frequency synthesizer and clock generation circuit, PLL is widely used in analog, digital and radio frequency chips. LC voltage-controlled oscillator or voltage-controlled ring oscillator, as the key unit in the phase-locked loop, directly determines the output frequency range of the phase-locked loop, and has a great influence on the remote phase noise of the phase-locked loop output. In recent years, consumer electronics have put forward higher requirements for IC products with small area, low power consumption and better performance. [0003] The traditional voltage-controlled ring oscillator has a high voltage-controlled gain and can cover a wide frequency range. However, when it is applied in a phase-locked loop, it is sensitive to the noise of th...

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Problems solved by technology

[0003] The traditional voltage-controlled ring oscillator has a high voltage-controlled gain and can cover a wide frequency range, but when it is applied in a phase-locked loop, it is se

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