With the ever-increasing demand for portable devices used in applications
such as wireless communication, mobile computing, consumer electronics, etc.,
the scaling of the CMOS process to deep submicron dimensions becomes more
important to achieve low-cost, low-power and high-performance digital systems.
However, this downscaling also requires similar shrinking of the supply...
This thesis proposes a novel technique for the design of pipelined and cyclic ADCs utilizing generalized radix gain stages. Several models have been proposed for the optimization of high performance pipelined ADCs by various researchers. This work builds upon them, using a simple but accurate model to estimate the optimal...
The objective of this work is to explore the feasibility of replacing conventional op-amps with inverters in switched-capacitor (SC) circuits. In order to verify the idea, a low-pass filter (LPF) and a second-order delta-sigma (∆Σ) analog-todigital converter (ADC) are designed in the 0.5-m CMOS technology. The low-pass filter structure is...
Digital phase-locked loops (PLLs) have been receiving increasing attention recently due to their ease of integration, scalability and performance comparable to their analog counterparts. In digital PLLs, increased resolution in time-to-digital conversion is desirable for improved noise performance. This work describes the design and simulation of a stochastic time-to-digital converter...
A radix-based calibration technique was previously proposed with a two-stage algorithmic analog-to-digital converter (ADC). The objective of this work is to verify the capability of radix-based calibration for a true multi-stage ADC. In order to prove the idea, a single bit-per-stage, 20-stage pipelined ADC is designed in a 0.35-μm CMOS...
Continuous process scale-down and emerging markets for low-power/low-voltage mobile systems call for low-voltage analog integrated circuits. Switched-capacitor circuits are the building blocks for analog signal processing and will encounter severe overdrive problems when operating at low-voltage conditions. There are several well-known techniques to bypass the problem. These approaches include: (1)...
This thesis proposes a novel fully digital technique for the estimation and correction of the DAC error in multi-bit delta sigma ADCs. The structure of the DAC error is indicated through a simple model for unit-element based DACs. The impact of the DAC error on the performance of ADC is...
To realize pipelined ADCs in deep-submicron processes, low voltage techniques
must be developed to work around problems created by limited supply voltages such as
the floating switch dead zone, reduced SNR, and reduced OpAmp performance.
This thesis analyzes standard and low voltage design issues for pipelined ADCs
and proposes a...
Pipeline analog-to-digital converters (ADCs) have long been used in high-speed systems for power-efficient data conversion. Broadband communication and video processing systems are placing high demands on converter accuracy and speed (above 14 bits and in the multiple-MHz range). The increasing converter requirements coupled with lower supply voltages in modern processes...
Circuits operating outside the earth’s atmosphere are more vulnerable to cosmic radiation and require special design consideration. The purpose of this work is to explore methods of mitigating the effect of radiation in phase locked loop (PLL) circuits. Several voltage controlled oscillators (VCOs) and two complete PLLs are designed and...