Evolution of the mobile communication standards and proliferation of hand-held devices mandate stringent Analog-to-Digital Converter (ADC) specifications. Among various ADCs, a ∆Σ ADC is best known as a power-efficient ADC when more than 12b is required. However, a conventional discrete-time (DT) ∆Σ Modulator (∆ΣM) is inadequate for low-power wideband applications...
Modern wireless System-on-Chips (SoCs), such as mobile handsets, sensor networks, and mm-wave systems, integrate an entire RF system on a single CMOS chip. Such highly complex systems require significant on-chip digital signal processing to help improve the performance of highly sensitive analog/RF components. The IC
market being competitive, the ability...
Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are widely used in wireless transceivers. Recently, continuous-time (CT) ΔΣ ADCs gain growing interest in wireless applications for their lower power consumption and wider input bandwidth as compared with the discrete-time (DT) counterparts.
In this thesis, a wideband low-power CT ΔΣ modulator for next generation...
High speed serial links are critical components for addressing the growing demand for I/O bandwidth in next-generation computing applications, such as many-core systems, backplane and optical data communications. Due to continued process scaling and circuit innovations, today's CMOS serial link transceivers can achieve tens of Gb/s per pin. However, most...
Delta-sigma analog-to-digital converters (ADCs) are suitable for many applications due to several advantages such as relaxed anti-aliasing filter, high signal-to noise and distortion ratio (SNDR) and most important of all, reduced sensitivity to
analog imperfections.This thesis introduces several structures to overcome loop imperfections and stability issues in delta-sigma modulators. First,...
Low noise oscillators are universally needed in digital systems for clock generation and synchronization, and in radio-frequency communication front-ends for frequency up- and down-conversion. Noise in oscillators results in timing jitter, and limits the clock frequency of digital systems. In radio-frequency communication systems, phase noise in oscillators lowers the signal-to-noise...
An automated method, requiring the fabrication of a small set of test structures, efficiently extracts the coefficients of Z-parameter based macromodels. The extraction approach has been validated for both heavily and lightly doped substrates and can be applied to a variety of technologies. After the parameters of a macromodel have...
This thesis describes circuit architectures and techniques that facilitate the
automatic synthesis and fabrication of analog-to-digital converters (ADCs). Since
automated synthesis already exists for digital circuits and is part of the digital
circuit design flow, this work demonstrates the feasibility of ADC synthesis with
little or no modification to presently...
Magnetically coupled passive transformers are increasingly integrated on-chip for
various analog and radio frequency (RF) applications including direct current
(DC) isolation, impedance transformation/matching, and conversion between
single-ended and differential signals. A primary motivation for the on-chip
integration of transformers is the overall size reduction and reduced cost.
However, the performance...
Analog-to-digital converters (ADCs) convert analog
continuous time signals into discrete time, digital format. One
precondition that must be met for conventional nyquist rate ADCs is
that the input signal must be suitably band-limited to an input
bandwidth less than the nyquist frequency. This mandates expensive
anti-alias filters which contribute to...