Baseband analog circuits in deep-submicron cmos technologies targeted for mobile multimedia

Three main analog circuit building blocks that are important for a mixed-signal system are investigated in this work. New building blocks with emphasis on power efficiency and compatibility with deep-submicron technology are proposed and experimental results from prototype integrated circuits are presented. Firstly, a 1.1GHz, 5th order, active-LC, Butterworth wideband equalizer that controls inter-symbol interference and provides anti-alias filtering for the subsequent analog to digital converter is presented. The equalizer design is based on a new series LC resonator biquad whose power efficiency is analytically shown to be better than a conventional Gm-C biquad. A prototype equalizer is fabricated in a standard 0.18μm CMOS technology. It is experimentally verified to achieve an equalization gain programmable over a 0-23dB range, 47dB SNR and -48dB IM3 while consuming 72mW of power. This corresponds to more than 7 times improvement in power efficiency over conventional Gm-C equalizers. Secondly, a load capacitance aware compensation for 3-stage amplifiers is presented. A class-AB 16W headphone driver designed using this scheme in 130nm technology is experimentally shown to handle 1pF to 22nF capacitive load while consuming as low as 1.2mW of quiescent power. It can deliver a maximum RMS power of 20mW to the load with -84.8dB THD and 92dB peak SNR, and it occupies a small area of 0.1mm2. The power consumption is reduced by about 10 times compared to drivers that can support such a wide range of capacitive loads. Thirdly, a novel approach to design of ADC in deep-submicron technology is described. The presented technique enables the usage of time-to-digital converter (TDC) in a delta-sigma modulator in a manner that takes advantage of its high timing precision while noise-shaping the error due to its limited time resolution. A prototype ADC designed based on this deep-submicron technology friendly architecture was fabricated in a 65nm digital CMOS technology. The ADC is experimentally shown to achieve 68dB dynamic range in 20MHz signal bandwidth while consuming 10.5mW of power. It is projected to reduce power and improve speed with technology scaling

Actinobacteria — A Biofactory of Novel Enzymes

Biocatalysis offers green and clean solutions to chemical processes and is emerging as an effective alternative to chemical technology. The chemical processes are now carried out by biocatalysts (enzymes) which are essential components of all biological systems. However, the utility of enzymes is not naive to us, as they have been a vital part of our lives from immemorial times. Their use in fermentation processes like wine and beer manufacture, vinegar production, and bread making has been practised for several decades. However, a commercial breakthrough happened during the middle of the 20th century with the first commercial protease production. Since then, due to the development of newer industries, the enzyme industry has not only seen a remarkable growth but has also matured with a technology-oriented perspective. Commercially available enzymes are derived from plants, animals, and microorganisms. However, a major fraction of enzymes are chiefly derived from microbes due to their ease of growth, nutritional requirements, and low-cost downstream processing. In addition, enzymes with new physical and physiological characteristics like high productivity, specificity, stability at extreme conditions, low cost of production, and tolerance to inhibitors are always the most sought after properties from an industrial standpoint. To meet the increasing demand of robust, high-turnover, economical, and easily available biocatalysts, research is always channelized for novelty in enzyme or its source or for improvement of existing enzymes by engineering at gene and protein levels. The novel actinobacteria and their industrially important enzymes will assist effective productivity and fulfill the requirements of industries

Evaluation of In-Vitro Antioxidant Activity of Biochanin A

This study was aimed to determine the in vitro antioxidant potential of biochanin A (BCA), an isoflavone phytochemical, by using various free radical scavenging assays. The free radical scavenging activity of BCA was evaluated by various standardized assays such as 1, 1-Diphenyl-2-Picryl Hydrazyl (DPPH●), 2, 2’-Azinobis-3-Ethylbenzothiazoline-6-Sulfonic Acid (ABTS●+), Ferric Reducing Antioxidant Power (FRAP),nitric oxide scavenging activity, reducing ability, hydroxy radical activity, superoxide anion scavenging activity, hydrogen peroxide radical, metal ion chelating activity  and phosphomolybdenum  assay. Four different concentrations of BCA (5, 10, 20, 40, μg/ml) were taken for evaluating the scavenging activity and which were compared with the antioxidant activity of standard ascorbic acid (AA). BCA showed good free radical scavenging activity, which was calculated as IC50. IC50 value of BCA was also comparable to Ascorbic acid (AA).Whereas AA was used as a standard. The scavenging activity of BCA was significantly elevated in a dose dependent manner. The BCA was exhibited a highest scavenging activity than the standard. The results obtained in the present study revealed that the BCA is an excellent free radical scavenger with the activity similar to that of AA. Keywords: Biochanin A, Antioxidant, Free radicals, Nitric oxides and Ascorbic aci