Continuous process scale-down and emerging markets for low-power/low-voltage mobile systems call for low-voltage analog integrated circuits. Switched-capacitor (SC) circuits are the building blocks for analog signal processing and will encounter severe overdrive problems when operating at low voltage conditions. There exist three techniques to solve the problem, but with their...
With the growing demand for portable/consumer electronics, such as digital
audio/video (AV), the downscaling of device dimensions, which enables the
integration of an increasing number of transistors in a single chip, is mandatory.
This trend also continuously pushes the power supply voltage down to reduce the
power consumption and improve...
High-accuracy and high-speed CMOS track-and-hold (T/H) or sample-and-hold (S/H) circuits are an important part of the analog-to-digital interface. The switched-capacitor (SC) circuits usually contain one or more op-amps whose dc offset, finite gain, finite bandwidth have a big impact on the accuracy of the track-and-hold circuit. Basic correlated double sampling...
IC designers are continuously facing the challenges from reduced CMOS feature sizes and supply voltages. ADCs that deliver satisfactory resolutions/speeds while utilizing the state-of-the-art technologies to save power are in high demand. The analog circuits are more and more assisted by various digital calibration techniques to get boosted performances. This...
In this thesis, novel design techniques have been proposed for implementing high-linearity SC circuits in a standard digital CMOS process. They use nonlinear MOSFET capacitors instead of linear double-poly capacitors. To reduce their nonlinearities, a bias voltage is applied to keep MOSFET capacitors in their accumulation regions. For further reduction...
This dissertation presents two high-speed pipeline successive approximation analog-to-digital converters (SAR ADCs). Capacitive DACs and resistive DACs are utilized in these two pipeline SAR ADCs, respectively.
The pipeline SAR ADC with capacitive DACs can save 50% switching power compared with other time-interleaved SAR ADCs since the total capacitance of the...
This dissertation presents an incremental analog-to-digital converter (ADC) with digital digital-to-analog converter (DAC) mismatch correction. A theoretical time-domain analysis technique was developed to predict the noise performance of the incremental ADC, and a new optimization technique was proposed to minimize the output noise.
In the calibration mode, the incremental ADC...
This thesis describes design techniques for high-performance switched-capacitor
(SC) circuits, primarily for high-linearity low-noise SC circuits in the presence of
component imperfections, such as nonlinear op-amp voltage transfer characteristics,
capacitor nonlinearities as well as the finite op-amp dc gain and op-amp offset and noise.
Various correlated-double-sampling (CDS) schemes are discussed,...
High performance multi-cell delta-sigma modulators are a preferred choice in applications which require programmability. Multi-cell delta-sigma modulators with M unit cells provide 10log10(M) SQNR improvement for the same thermal noise and bias power due to the uncorrelated quantization noises of the M unit ADCs. This concept is used in this...
Data converters are essential interface circuits between the analog world that people live in and the digital processors that people live with. Linearity, which often is a tradeoff against other performance criteria, is one of the major performance demands from applications for both analog-to-digital converts (ADC) and digital-to-analog converters (DAC)....