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...
There is a large and growing market for portable consumer audio products
with very small size. As the size of these products is reduced, the area occupied
by batteries becomes significant and hence limits the number of batteries to one.
In order to build such small products, high levels of...
The demand for portable electronic systems and the continued
down-scaling of device dimensions resulted in rapid improvement in
the performance of integrated systems. Several low-voltage design
techniques have been proposed to operate analog circuits with sub-1V
supply. However, these techniques require higher power consumption
to achieve large dynamic range while...
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...
Real world is analog but the processing of signals can best be done in digital domain. So the need for Analog to Digital Converters(ADCs) is ever rising as more and more applications set in. With the advent of mobile technology, power in electronic equipment is being driven down to get...
The world market for sensors is several hundred million dollars growing at an annual rate of 20 percent with accelerometers comprising 19 percent of the market. With an increasing market, a wide range of applications with varying degrees of resolution are in demand. Therefore, there is sufficient motivation for developing...
In this work a new voltage buffer, the drain-follower, achieves 300MHz band-width with 2pF load, a dc gain of 0.993V/V, 1mV offset voltage, -60 dB total harmonic distortion at 1.4Vpp output voltage and 6.5mW power dissipation from 5V supply. A unity-gain buffer switched-capacitor biquad filter has been implemented in 0.5μm...
Multi-stage delta-sigma (ΔΣ) architectures, commonly known as MASH, are the preferred choice for analog-to-digital converters (ADCs) used in broadband communication applications, where high-resolution (above 14 bits) and high-bandwidth (several MHz) performances are required. Current state-of-the-art designs are capable of as much as 5-MS/s output data rates with 90-dB SNR. However,...
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...
Switched-capacitor (SC) circuits are commonly used for analog signal processing because they can be used to realize precision filters and data converters on an integrated circuit (IC). However, for high speed applications SC circuit operating speeds are limited by the internally-compensated opamps found in SC integrators, a common building block...
The design of a switched capacitor successive approximation A/D converter is discussed in this thesis. This design adopts a novel capacitance mismatch error cancellation algorithm proposed in references [25, 27]. Detailed charge domain analysis is given in this thesis, which results in an improvement of the proposed algorithm by tracing...
A duty-cycle controlled switched resistor is a tunable resistive element that uses pulse width modulation as the method of tuning. This thesis will describe the operation of switched resistors and propose several circuit architectures that are well suited to the use of switched resistors. These architectures include filters, mixers, and...
Utilizing a two-capacitor topology, the digital implementation of an audio-band successive-approximation analog-to-digital converter (ADC) is explored in the context of mismatch-shaping where the mismatch estimates are accurate to the first order. A second-order Δ∑ loop was found to be effective in system simulations given a 0.1% capacitor mismatch. Spectral analysis...
Spacecrafts experience radiation in the course of their operation
and all electronic equipment on board these spacecrafts has to
be designed to withstand the effects of this radiation.
This thesis describes the effects of total ionization dose (TID)
and single event transients (SET) in phase-locked loops - an
important circuit...
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...
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)...
Scaling of CMOS technology has progressed relentlessly for the past several
decades. In order for this unprecedented scaling to benefit the performance of
large digital systems, the communication bandwidth between integrated circuits
(ICs) must scale accordingly. However, interconnect technology does not scale as
aggressively, making communication between chips the major...
Recently, switched capacitor DC/DC converters are extensively used in portable electronic devices because they feature many advantages, such as high efficiency, small package, low quiescent current, minimal external components and low cost. In this thesis, two step-down switched capacitor DC/DC converters are designed. One has the fixed output options 1.5V,...
This thesis presents methods to reduce the effects of finite opamp DC gain, output voltage swing limitations in opamps, and component mismatches. The primary contribution of this thesis is a new switched-capacitor method named correlated level shifting (CLS). CLS enables true rail-to-rail operation by storing an estimate of the desired...
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...