Sharif Digital Repository

A new technique for improving the performance of low-voltage folding ADC's by extending the input range is presented. It is shown that by using both PMOS and NMOS differential pairs in the folding blocks, the overall input voltage range of the ADC can be increased to rail-to-rail. A novel self-adjustment method is also introduced to compensate for the different input-output characteristics of PMOS and NMOS differential pairs. A low voltage 8-bit 80 MSample/s folding/interpolating ADC is then designed and fabricated in a 0.18 μm CMOS process. Operating with a supply voltage as low as 1.2 V, measurements show an INL below ±0.55 LSB, SNDR of 43.5 dB at 80 MHz Sampling Frequency and power... 

Flow mediated dilation (FMD) is a non-invasive method for endothelial function assessment providing an index extracted from ultrasonic B-mode images. Although utilized in the research community, the difficulty of its application and high cost of ultrasonic devices prevent it from being widely used in clinical settings. In this study we show that substituting the ultrasonic device with more easily handled and low cost photoplethysmography and electrocardiography is possible. We introduce new indices based on the photoplethysmogram (PPG) and electrocardiogram (ECG) and show that they are correlated with the ultrasound-based FMD Index. To this end, a conventional ultrasound FMD test was carried... 

Atherosclerosis is a major cause of coronary artery disease leading to morbidity and mortality worldwide. Currently, coronary angiography is considered to be the most accurate technique to diagnose coronary artery disease (CAD). However, this technique is an invasive and expensive procedure with risks of serious complications. Since the symptoms of CAD are not noticed until advanced stages of the disease, early and effective diagnosis of CAD is considered a pertinent measure. In this paper, a non-invasive optical signal, the finger photoplethysmogram (PPG) obtained before and after reactive hyperemia is investigated to discriminate between subjects with different CAD conditions. To this end,... 

Nowadays, manufacturing enterprises have been faced with a globalized competitive environment. In this fierce condition, Cloud Manufacturing paradigm emerged as a promising concept for competition. It provides effective solutions and tools for manufacturing enterprises to collaborate in globalized market. The revolution that Cloud Manufacturing has created is based on the redefinition of the classic methods to those which are appropriate for todays' modern and globalized manufacturing environments. In parallel with cloud-based revolution, the expansion of internet-based technologies has been started. These technologies previously have been applied in many fields and resulted in... 

The cloud manufacturing paradigm has been known as one of the best solutions for today's competitive manufacturing environments. This paradigm insists on using a manufacturing service oriented approach for fulfilling the manufacturing enterprise resource management by the access to global availability of manufacturing services. The proposed service oriented approach covers a wide area of manufacturing resource management from infrastructures to platforms and applications. However, due to wide global distributions of manufacturing clouds, the service oriented architectures which are designed in the clouds cannot communicate with each other. This is mainly due to concentration of cloud... 

The emergence of the globalization paradigm in manufacturing industry has changed the markets’ circumstances, and accordingly manufacturing systems need to be compatibilized with these situations. There are many solutions to assist manufacturing systems for this purpose. Computerized systems and their related solutions were being the most attractive ones for manufacturing systems in recent decade. Developing such systems and exploiting from the advantages of such solutions requires a consistent foundation. Computer Integrated Manufacturing (CIM) emerged as a philosophy to provide such foundation, and to assist the computerized manufacturing solutions. Despite of the high potentials of the... 

An 8-bit High-speed folding/interpolating ADC is presented. Designed in 0.18μm CMOS technology, the ADC dissipates only 50mW from a single 1.5V supply. A novel technique based on using both N and P folding cells is used to widen the input range and a self-calibration technique based on using Trimmable MOSFETs is employed to improve the static and dynamic performance  

In this paper, a new method for automatic cancellation of mismatch-induced errors in folding ADC is introduced. Using "Trimmable MOSFET's" for input transistors, this method results in considerable reduction of the size of speed-determining transistors while keeping integral non-linearity (INL) arbitrarily low. Using this technique, an 8-bit folding ADC is re-designed and its performance is compared to the original work.©2005 IEEE  

This paper investigates the performance of a MOS track-and-hold circuit as the front end of a wide input range and high-speed single-sided ADC. In order to reduce charge injection and clock feedthrough errors, a new technique for employing a dummy transistor in the bootstrapped switch of the track and hold circuit is introduced. Performance of the proposed circuit for the two cases of constant and non-linear hold capacitor is studied. It is also shown that how and when dummy switch and bulk switching method can improve the accuracy of theT/H. © IEICE 2007