Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are traditionally used in high quality audio systems, instrumentation and measurement (I&M) and biomedical devices. With the continued downscaling of CMOS technology, they are becoming popular in wideband applications such as wireless and wired communication systems,high-definition television and radar systems. There are two general realizations...
This dissertation presents a phase domain in-loop-bandwidth spread-spectrum clock generation technique. In this proposed technique, a charge-based discrete-time loop filter is proposed to enable the phase domain in-loop-bandwidth spread-spectrum modulation without a delta-sigma modulator or time-to-digital converter. The in-loop-bandwidth modulation technique maximizes the loop bandwidth to improve phase noise suppression...
Portable, high power efficiency communication devices is a growing market in the semiconductor industry. Analog-to-digital converters (ADC) are key interface that are used to digitize the sensed information. Recently, digital techniques have been proposed to improve analog building block power efficiency in sub-micron technologies. This research focuses on mixed signal...
Digital-to-analog converters (DACs) with wide dynamic range and high
linearity are required for high-end audio applications. A multi-bit delta sigma
audio DAC, using a novel gain-correction technique, is described in this thesis. For
widely varying on-chip RC time constant, the DAC gain can be accurately
controlled by the correction circuitry....
Part I: Plasmonic color filters can be manufactured at lower cost since they can be fabricated in single lithographic process step as compared to Fabry-Perot based filters. In addition, they have narrow passband making resolving sharp features in sample spectrum possible. Due to these benefits, in this thesis, Plasmonic color...
The most accurate method for performing analog signal processing in MOS (metal-oxide-semiconductor) integrated circuits is through the use of switched-capacitor circuits. A switched-capacitor circuit operates as a discrete-time signal processor. These circuits have been used in a variety of applications, such as filters, gain stages, voltage-controlled oscillators, and modulators. A...
Oversampled delta-sigma modulation is one of the widely used A/D conversion
techniques for narrow bandwidth signals. In this study several new lowpass and
bandpass delta-sigma modulator architectures as well as novel pseudo-N-path integrators
that can be used in implementing these architectures are proposed.
By using multiplexing techniques the new lowpass...
Successive-approximation-register (SAR) analog-to-digital converters are popular for medium accuracy, medium speed and low power applications, such as in biomedical applications. They have low latency and simple architecture compared with ΔΣ ADCs. This is because of SAR ADCs’ binary searching scheme. Furthermore, SAR ADCs can apply oversampling and noise shaping schemes...
As advanced wired and wireless communication systems attempt to achieve higher performance, the demand for high resolution and wide signal bandwidth in their associated ADCs is strongly increased. Recently, time-domain quantization has drawn attention from its scalability in deep submicron CMOS processes. Furthermore, there are several interesting aspects of time-domain...
Phase-Locked Loops (PLLs) are essential building blocks in many communication systems. Designing high performance analog PLLs in the presence of technology imposed constraints such as leakage, poor analog transistor behavior, process variability, and low supply voltage is a challenging task. To overcome these drawbacks, digital PLLs (DPLLs) have recently emerged...