This paper presents a tutorial on delta-sigma fractional-N PLLs for frequency synthesis. The presentation assumes the reader has a working knowledge of integer-N PLLs. It builds on this knowledge by introducing the additional concepts required to understand ΔΣ fractional-N PLLs. After explaining the limitations of integerN PLLs with respect to tuning resolution, the paper introduces the delta-s...

a question of the existence of delta-convergent sequences that vanish at the support of the limit Dirac delta function and gave an example of sequences of this type. It is a sequence of even functions that don't have a compact support. Motivated by the question in this paper we develop some results concerning delta sequences and show more examples of delta sequences of the type with or without ...

A new application of sigma-delta modulation has emerged in soft switching three phase power electronic converters. For this application, a conventional sigma-delta modulator with scalar signals and binary quantizer is generalized to a sigma-delta modulator with vector signals and a truncated hexagonal lattice quantizer. This vector sigma-delta modulator has an interesting output spectrum which ...

A ring $R$ with an automorphism $sigma$ and a $sigma$-derivation $delta$ is called $delta$-quasi-Baer (resp., $sigma$-invariant quasi-Baer) if the right annihilator of every $delta$-ideal (resp., $sigma$-invariant ideal) of $R$ is generated by an idempotent, as a right ideal. In this paper, we study Baer and quasi-Baer properties of skew PBW extensions. More exactly, let $A=sigma(R)leftlangle x...

Abstract: In this paper, a novel spatial domain 2-D sigma-delta modulation using two-layered discrete-time cellular neural networks (DT-CNNs) with multi-stage noise shaping (MASH) property is proposed. Although the sigmadelta modulation is widely used for realizing of analog to digital converter (ADC), sigma-delta concepts are only for 1-D signals. Signal processing in the digital domain is ext...

This paper proposes a feed-forward control in a halfbridge resonant dc link inverter. The configuration of feed-forward control is based on synchronous sigma-delta modulation and the halfbridge resonant dc link inverter consists of two inductors, one capacitor and two power switches. The simulation results show the proposed technique can reject non-ideal dc bus improving the total harmonic dist...

A Sigma-delta modulator is designed in 180nm CMOS process for digital Audio applications. This design is simulated on S-Edit of Tanner EDA tool. In this design continuous time sigma-delta modulator is implemented to reduce the noise problem. This sigma-delta modulator also helps to reduce power consumption of circuit. In these design two stage op-amps is used to implement modulator. Also this d...

A 2-bit adaptive sigma delta modulation system that inherently eliminates the idle tones present in conventional and other adaptive sigma delta systems is described. The system incorporates both memory and look-ahead instantaneous step-size estimations and, as shown by computer simulation results apart from eliminating the unwanted idle tones despite dithering, it offers improved SNR performanc...

This paper brief the use of very high precision Noise shaping sigma delta modulation techniques for high applications that require a signal-to-noise ratio and high resolution. A continuous-time delta-sigma A/D modulator with OSR of 40, signal bandwidth of 1.5625 MHz and clocked at 500MHz is implemented. This achieves 78 dB SNR and 12 bits of resolution.