Digital radio receivers must perform the analog-to-digital conversion of bandpass signals. For signals with small relative bandwidths, bandpass XA analog-to-digi ta l converters offer high signal-to-noise ratios at significantly lower sampling rates than are required for lowpass ZA converters, while still providing excellent linearity. A 4thorder bandpass ZA modulator implemented in a 3 pm CMOS...

A new noise-shaping coding scheme is derived by using an autoregressive moving average model and by bounding and minimizing its reconstruction error. The stability of the system and performance can be analysed easily. All-zero first order and second order shaping filters are used to study the effect of the proposed scheme on the perceptual quality of speech signals.

This paper describes the design of a Sigma-Delta modulator aimed for A/D conversion in xDSL applications, featuring 14-bit@4Msample/s in a 0.35μm mainstream digital CMOS technology. Architecture selection, modulator sizing and cell sizing tasks where supported by a CAD methodology, thus allowing us to obtain a power efficient implementation in a short design cycle.

Sigma delta modulation M has become a widespread method of analogue to digital conversion however its operation has not been completely de ned The majority of the analysis carried out on the circuit has been from a linear standpoint with non linear analysis hinting at hidden complexities in the modulator s operation The sigma delta modulator itself is a non linear system consisting as it does o...

Enhancement of the performance and speed of the Digital Signal processing processors are the major challenge due to its wide spread real world applications. At the same time high quality (less erroneous) and high speed digital inputs are required for these DSP Processors. Hence the high performance and high speed A/D or D/A converter design is the another major issue for performance and speed m...

Abdelghani Dendouga, Nour-Eddine Bouguechal, Souhil Kouda and Samir Barra Advanced Electronic Laboratory, Batna University, Algeria 05 Avenue Chahid Boukhlouf, 05000 BATNA, ALGERIE E-mail: [email protected] Abstract—Sigma delta modulators (ΣΔMs) form part of the core of today’s mixed-signal designs. The ongoing research on these devices shows the potential of ΣΔ data converters as a promi...

frequency 40MHz with 78dB Dynamic Range in a 0.35µm CMOS process. I. INTRODUCTION Oversampling bandpass A/D is widely used because of its increased accuracy and decreased analog front-end circuitries in transceiver systems. High frequency digital processing is more robust than its analog counterpart, and does not have the analog circuit imperfections. Digital IF extraction is also very benefici...

In this paper, a complete high-speed Continuous-Time Bandpass Delta-Sigma modulator for digital receiver applications is modeled, using VHDL-AMS. The main Continuous-Time DeltaSigma modulator’s nonidealities such as excess loop delay, clock jitter and multi-bit feedback DAC element mismatch in the modulator loop are also modeled and their effects evaluated. An accurate understanding of these no...

This paper presents the design of a second-order Sigma-Delta modulator for digital audio. This modulator has been designed at 3 V power supply with oversampling ratio of 256 and simulated in a 0.6 μm CMOS technology. The simulated results give SNDR of 96 dB for a 24 KHz signal bandwidth. The sampling frequency is 12.288 MHz and the Nyquist rate of the modulator is 48 KHz.