A simple technique is presented to realize a digitally programmable voltage mode quadrature oscillator using second generation current conveyors. Firstly, the current conveyors based tunable quadrature oscillator is realised. A digital block is introduced in the realized tunable quadrature oscillator so that the oscillator can be controlled digitally. The realized Digitally Programmable Quadrat...

A CMOS voltage controlled Op-Amp oscillator based on N-stage single-ended chain of different inverter types is described in this paper. This paper describes a performance and comparison of a ring oscillator based VCO and an Op-Amp based oscillator based VCO. The VCO is intended to operate in a op-amp based VCO to generate local oscillator frequency for an system. An oscillator topology an impro...

This paper presents a general ring oscillator circuit topology for high speed operation, multiphase output and wide range tuning. The topology use sub-feedback inverters to construct fast loop for long chain ring oscillator to achieve high speed. The operating frequency of the ring oscillator is directly proportional to the transconductance (G,) of subfeedback inverters which can be controlled ...

this paper proposes a hybrid control scheme for the synchronization of two chaotic duffing oscillator system, subject to uncertainties and external disturbances. the novelty of this scheme is that the linear quadratic regulation (lqr) control, sliding mode (sm) control and gaussian radial basis function neural network (grbfnn) control are combined to chaos synchronization with respect to extern...

In this paper we introduce a CMOS low voltage/low power (LV/LP) voltage controlled oscillator (VCO). It includes a simple V-I converter, a current controlled ring oscillator based on new differential delay cells, and a source-coupled differential pair to convert differential signal to single-ended signal. The V-I converter is implemented as a source follower type, exhibiting excellent linearity...

A 1.2V 5GHz low-cost voltage-controlled oscillator (VCO) with active common mode feedback has been implemented in a CMOS/RF 90nm technology for a robust I/Q generation using a frequency divider-by-2 (DIV2). As the input common mode of the DIV2 affects critically its performance, a calibration method to correct the output common mode of the VCO has been proposed and validated through post-layout...

The numerical controlled oscillator has wide application in radar, digital receiver, and software radio system. Firstly, this paper introduces the traditional CORDIC algorithm. Then in order to improve computing speed and save resources, this paper proposes a kind of hybrid CORDIC algorithm based on phase rotation estimation applied in numerical controlled oscillator (NCO). Through estimating t...

In this paper, a new differential delay cell is proposed and 16-bit Digital Controlled Oscillator (DCO) based on proposed delay cell is designed. The 16-bit DCO consist of 4-stages differential delay cell in ring structure and a digital control scheme has been used to improved noise characteristics. The structure of the DCO utilizes dual delay path techniques to achieve high oscillation frequen...

This paper demonstrates a pulse width controlled PLL without using an LPF. A pulse width controlled oscillator accepts the PFD output where its pulse width controls the oscillation frequency. In the pulse width controlled oscillator, the input pulse width is converted into soft thermometer code through a time to soft thermometer code converter and the code controls the ring oscillator frequency...