A General Formula for Impulse-Invariant Transformation for Continuous-Time Delta-Sigma Modulators

this paper presents a generalised new formula for impulse-invariant transformation which can be used to convert an nth-order Discrete-Time (DT) ΔΣ modulator to an nth-order equivalent Continuous-Time (CT) ΔΣ modulator. Impulse-invariant transformation formulas have been published in many open literature articles for s-domain to z-domain conversion and vice-versa. However, some of the published works contain omissions and oversights. To verify the newly derived formulas, very many designs of varying orders have been tested and a representative 4th-order single-loop DT ΔΣ modulator converted to an equivalent CT ΔΣ modulator through the new formulas are presented in this paper. The simulation results confirm that the CT ΔΣ modulator which has been derived by these formulas works in accordance with the initial DT specifications without any noticeable degradation in performance in comparison to its original DT ΔΣ modulator prototype

Design and Simulation of a 3rd-order Discrete-Time Time-Interleaved Delta-Sigma Modulator with Shared Integrators between Two Paths

This paper presents the design and simulation of a 3rd-order two-path Discrete-Time Time-Interleaved (DTTI) ΔΣ modulator. By exploiting the concept of the time-interleaving techniques and time domain equations, a conventional 3rd-order Discrete-Time (DT) ΔΣ modulator is converted to a corresponding 3rd-order two-path DTTI counterpart. For the sake of saving power and silicon area, the integrators between the two paths of the DTTI ΔΣ modulator are shared. Using one set of integrators makes the DTTI ΔΣ modulator robust to path mismatch effects compared to the typical DTTI ΔΣ modulator which has individual integrators in all paths. A problem arises out of sharing integrators between paths which we call the delayless feedback problem. A solution for this problem is proposed in this paper and for an OverSampling Ratio (OSR) of 16 and a clock frequency of 320MHz, a maximum SNR of 76.5dB is obtained

Design of a Delayless Feedback Path Free 2nd-order Two-Path Time-Interleaved Discrete-Time Delta-Sigma Modulator- a New Approach

This paper presents the design procedure for a 2nd_order two-path Discrete-Time Time-Interleaved (DTTI) ΔΣ modulator from a conventional single-loop 2nd-order Discrete-Time (DT) ΔΣ modulator through the use of time domain equations and time-interleaving concepts [1]. The resulting modulator is free from the delayless feedback path and has only one set of integrators. The delayless feedback path issue in Time-Interleaved (TI) ΔΣ modulators is a critical restriction for the implementation of TI ΔΣ modulators and is effectively eliminated through the use of the approach proposed in this paper. The DTTI ΔΣ modulator requires only three op-amps and two quantizers both of which work concurrently, in comparison to the single-loop DT counterpart that also deploys two op-amps. For an OverSampling Ratio (OSR) of 16 and a clock frequency of 640MHz, our simulation results show a maximum Signal-to-Noise Ratio (SNR) for the DTTI ΔΣ modulator to be 70.5dB with an input bandwidth of 20MHz which has 15dB improvement in comparison to its single-loop, single-path DT counterpart

A 28mW 320MHz 3rd–Order Continuous-Time Time-Interleaved Delta-Sigma Modulator with 10MHz Bandwidth and 12 Bits of Resolution

this paper presents a 3rd-order two-path Continuous-Time Time-Interleaved (CTTI) delta-sigma modulator which is implemented in standard 90nm CMOS technology. The architecture uses a novel method to solve the delayless feedback path issue arising from the sharing of integrators between paths. The clock frequency of the modulator is 320MHz but integrators, quantizers and DACs operate at 160MHz. The modulator achieves a dynamic range of 12 bits over a bandwidth of 10MHz and dissipates only 28mW of power from a 1.8-V supply

Simplified Orthograde Apical Plug and Intra-Orifice Barriers for Resolving a Complex Endodontic Challenge: A Case Report

Successful endodontic treatments are contingent upon establishing a hermetic seal within the root canal system. This seal is pivotal in preventing/resolving apical periodontitis. This case report introduces a simplified orthograde apical plug and intra-orifice barrier technique as an effective alternative to previously unsuccessful invasive nonsurgical and surgical treatments. A 28-year-old patient presented with persistent discomfort and localized swelling in the furcation area of the mandibular left first molar. The tooth had previously undergone both root canal therapy and surgical retreatment. A distinctive feature of this case was the unconventional amputation of the mesial root, unlike conventional periradicular surgery or root amputation. This unusual scenario was accompanied by the presence of a large endodontic lesion. An apical plug, utilizing calcium-enriched mixture (CEM) cement, was placed, complemented by the use of CEM intra-orifice barriers to ensure the hermetic sealing of the entire root canal system. Long-term follow-up assessment demonstrated the complete healing of the preexisting large endodontic lesion. This case underscores the significance of proper diagnosis, right treatment planning, and considering conservative treatment options for complex cases, highlighting the pivotal role played by a reliable seal in achieving successful results in endodontic procedures

How to design an inclusive care, based on individuals’ social cognition capacities to improve quality of life for people with dementia?

Social isolation is one of the consequences of dementia. By progression of dementia the ability to talk, remember, and orient oneself in space gradually reduces and the need for assistance with daily tasks increases. These physical and mental abatement causes decline in social, behavioural, and emotional capabilities

How Sport and Art could be Effective in the Fields of Social, Cognitive and Emotional Learning?

AbstractMission of education in each country is to strengthen human attitude, promoting its philosophy and developing the individual's ability to live healthy and productive in the society. One of the features in the modern education is special attention to psychological and physical activities that students do at school. Development and enrichment of sports and arts activities, according to fairly centralized approach in curriculum planning and lack of sufficient attention to developing learner's social, emotional and cognitive skills in the teaching-learning process is needed. Thinking in this area makes obvious the emergence of new policy making in the school formal programs

Sensory for dementia, light and sound in long term care environment

People with dementia show behavioural change in respect to their environment. Noise and Light are the two most obvious sources of sensory stimulation in the environment, and when ignored or mismanaged, they can become important sources of under or over stimulation for the person with dementia (Dewing, 2009). The purpose of this study is to gain an understanding of the sensory implications regarding light and sound in combinations with the common disturbances pertaining to dementia patients such as anxiety, sleep deprivation, agitation and malnutrition. Implementing elements such as light panels, sound barriers and appropriate lux levels have been considered as part of the rehabilitation for dementia patients. As these aspects are underutilized in many healthcare settings, a set of instructional guidelines would be helpful in designing a dementia friendly unit or to improve the environment design of an existing unit. Of course further study must be conducted to evaluate these interventions

The relationship between english pronunciation self-concept and english learning

English pronunciation self-concept refers to self-evaluation of a person's English pronunciation proficiency which is shaped during the time spent for pronunciation learning (Gimson, 1980). The present paper aims at investigating the possible correlation between English pronunciation self-concept and English language learning. Furthermore, the relationship between global English self-concept and classroom anxieties are examined in the Iranian context. To this end, Xiuquan zhu’s (2005) questionnaire was administrated to the total of 100 English as a foreign language (EFL) students. Moreover, to assess students general English performance and their pronunciation proficiency two kinds of tests were taken by the participants. Descriptive statistics was used to turn the raw data to the interpretable forms. The analysis revealed statistically significant correlation between English pronunciation self-concept and global English self-concept with in turn leads to efficient English language performance. However, negative correlation is obtained regarding English classroom anxiety and English pronunciation self-concept. Because of facilitating role of pronunciation self-concept in English language acquisition, the findings of the present study suggest that due attention should be paid on the English pronunciation self-concept in foreign language learning teaching-learning environments