In this study we have replaced all 13 methionine residues in the cytochrome P450 BM-3 heme domain (463 amino acids) with the isosteric methionine analog norleucine. This experiment has provided a means of testing the functional limits of globally incorporating into an enzyme an unnatural amino acid in place of its natural analog, and also an efficient way to test whether inactivation during per...

Operational amplifiers (op amps) are as prolific in analog circuits as salt and pepper is on food. They are sprinkled throughout the sensor data acquisition system, performing a variety of functions. For instance, at the sensor interface, amplifiers are used to buffer and gain the sensor output. The current or voltage excitation to the sensor, quite often is generated by an amplifier circuit. F...

The paper provides an overview of the development of a self-learning computing chip in the new 0.18 micron copper technology. The chip realizes an architecture that achieves the task of self-learning execution times in the micro to milli seconds. The core consists of basic building blocks of 4quadrant multipliers, trans-conductance amplifiers, and active load resistances, for analog (forward-) ...

Considerable progress has been made in integrating multi-Gb/s functions into silicon chips for dataand telecommunication applications. This paper reviews the key requirements for implementing such functions in monolithic form and describes their implementation in the IBM SiGe BiCMOS technology. Aspects focused on are the integration of 10 –13-Gb/s serializer/deserializer chips with subpicosecon...

The Operational Transconductance Amplifier is a basic building blocks found in many analog circuits such as data converter’s (ADC& DAC) and Gm-c filters. The OTA is an amplifier whose differential input voltage produces an output current .Thus ,it is a voltage controlled current source(VCCS) whereas the Op-amp are voltage controlled voltage source(VCVS). There is usually an additional input for...

Neuromorphic systems make use of a set of specific functions that exhibit specific or unconventional behavior. These include winner-take-all (WTA), weighted average, and thresholding functions. These can be integrated using various design techniques, including analog, digital, standard, and subthreshold realizations. In this paper, we present a brief survey of charge-based realizations of sever...

Title of dissertation: CIRCUIT DESIGN AND ROUTING FOR FIELD PROGRAMMABLE ANALOG ARRAYS Ji Luo, Doctor of Philosophy, 2005 Dissertation directed by: Professor Joseph Bernstein Professor Martin Peckerar Department of Electrical & Computer Engineering Accurate, low-cost, rapid-prototyping techniques for analog circuits have been a long awaited dream for analog designers. However, due to the inhere...

Nanoscale resistive switching devices (memristive devices or memristors) have been studied for a number of applications ranging from non-volatile memory, logic to neuromorphic systems. However a major challenge is to address the potentially large variations in space and time in these nanoscale devices. Here we show that in metal-filament based memristive devices the switching can be fully stoch...

In this paper, we present a block of adaptive weight change (AWC) mechanism for analog current-mode Kohonen's Neural Network (KNN) implemented in CMOS 0.18 μm technology. As some other essential building blocks of KNNs dealing with the calculations of the Euclidean distance, formation of a conscience mechanism and a determination of the winner-takes-all (WTA) circuits have been already develope...

This paper presents the design of a 3rd-order lowpass analog-to-digital (A/D) converter using a continuous-time (CT) loop lter. The loop lter has been implemented by using active RC-integrators. The in uence of the low supply voltage on the building blocks such as the ampli er and the common mode feedback as well as on the overall modulator is discussed. Simulation results of the 1:5V CT A/D co...