A High Linearity Bootstrapped Switch with Leakage Current Suppressed for GS/s Sampling Rate ADC

Author(s):  
Jingchao Lan ◽  
Yan Zheng ◽  
Yimin Wu ◽  
Min Chen ◽  
Fan Ye ◽  
...  
2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Yi Zhang ◽  
Qiao Meng ◽  
Changchun Zhang ◽  
Ying Zhang ◽  
Yufeng Guo ◽  
...  

A single channel 2 GSps, 8-bit folding and interpolation (F&I) analog-to-digital converter (ADC) with foreground calibration in TSMC 90 nm CMOS technology is presented in this paper. The ADC utilizes cascaded folding, which incorporates an interstage sample-and-hold amplifier between the two stages of folding circuits to enhance the quantization time. A master-slave track-and-hold amplifier (THA) with bootstrapped switch is taken as the front-end circuit to improve ADC’s performance. The foreground digital assisted calibration has also been employed to correct the error of zero-crossing point caused by the circuit offset, thus improving the linearity of the ADC. Chip area of the whole ADC including pads is 930 μm × 930 μm. Postsimulation results demonstrate that, under a single supply of 1.2 volts, the power consumption is 210 mW. For the sampling rate of 2 GSps, the signal to noise and distortion ratio (SNDR) is 45.93 dB for Nyquist input signal.


2014 ◽  
Vol 31 (5) ◽  
pp. 406-410
Author(s):  
Zhang Zhang ◽  
Mingxin Song ◽  
Chubin Wu ◽  
Guangjun Xie

Author(s):  
E. Voelkl ◽  
L. F. Allard

The conventional discrete Fourier transform can be extended to a discrete Extended Fourier transform (EFT). The EFT allows to work with discrete data in close analogy to the optical bench, where continuous data are processed. The EFT includes a capability to increase or decrease the resolution in Fourier space (thus the argument that CCD cameras with a higher number of pixels to increase the resolution in Fourier space is no longer valid). Fourier transforms may also be shifted with arbitrary increments, which is important in electron holography. Still, the analogy between the optical bench and discrete optics on a computer is limited by the Nyquist limit. In this abstract we discuss the capability with the EFT to change the initial sampling rate si of a recorded or simulated image to any other(final) sampling rate sf.


2009 ◽  
Vol 23 (4) ◽  
pp. 191-198 ◽  
Author(s):  
Suzannah K. Helps ◽  
Samantha J. Broyd ◽  
Christopher J. James ◽  
Anke Karl ◽  
Edmund J. S. Sonuga-Barke

Background: The default mode interference hypothesis ( Sonuga-Barke & Castellanos, 2007 ) predicts (1) the attenuation of very low frequency oscillations (VLFO; e.g., .05 Hz) in brain activity within the default mode network during the transition from rest to task, and (2) that failures to attenuate in this way will lead to an increased likelihood of periodic attention lapses that are synchronized to the VLFO pattern. Here, we tested these predictions using DC-EEG recordings within and outside of a previously identified network of electrode locations hypothesized to reflect DMN activity (i.e., S3 network; Helps et al., 2008 ). Method: 24 young adults (mean age 22.3 years; 8 male), sampled to include a wide range of ADHD symptoms, took part in a study of rest to task transitions. Two conditions were compared: 5 min of rest (eyes open) and a 10-min simple 2-choice RT task with a relatively high sampling rate (ISI 1 s). DC-EEG was recorded during both conditions, and the low-frequency spectrum was decomposed and measures of the power within specific bands extracted. Results: Shift from rest to task led to an attenuation of VLFO activity within the S3 network which was inversely associated with ADHD symptoms. RT during task also showed a VLFO signature. During task there was a small but significant degree of synchronization between EEG and RT in the VLFO band. Attenuators showed a lower degree of synchrony than nonattenuators. Discussion: The results provide some initial EEG-based support for the default mode interference hypothesis and suggest that failure to attenuate VLFO in the S3 network is associated with higher synchrony between low-frequency brain activity and RT fluctuations during a simple RT task. Although significant, the effects were small and future research should employ tasks with a higher sampling rate to increase the possibility of extracting robust and stable signals.


Author(s):  
Yu. E. Moskalenko ◽  
T. I. Kravchenko ◽  
Yu. V. Novozhilova

Introduction. Slow fl uctuations in the volume and pressure of liquids in the cranial cavity have been known for a long time and have been studied for more than 100 years. However, their quantitative indicators and their practical signifi cance remain unclear until now due to the diffi culties of research. Nevertheless, it was found that they were connected with the brain activity, which made it possible to use them as one of the physiological indicators in studying the problems of manned space fl ights. Goal of research — to study the possibility of using spectral analysis of slow fl uctuations of the volume of liquids inside the cranium in order to realize the quantitative assessment of their indicators with the use of modern microelectronics and computer technology.Materials and methods. In order to solve this problem we created a complex, in which rheoencephalograph-RG-01 («Mizar») was used as a converter-modulator of physiological signals into electrical oscillations. The device was connected with the ADC (Firm «ADIstrument»), Its software allows to calculate the spectrogram with a sampling rate of 128 kHz. Studies were conducted on volunteers of younger, middle and older age groups. The respiratory rate and the electrocardiography were registered together with the rheoencephalography. Electrodes were fi xed on the volonteers′ fronto-mastoid area.Results. Slow fl uctuations the cranium representan independent physiological phenomenon. The most considerable and valuable were fl uctuations in 0,1–0,3 Hz. It was found that current frequency of 100 or 200 kHz and frequency for quantization of 80–100 kHz was optimal for performing their spectrograms. The structure of such diagram consists of 4–7 peaks with amplitude of 0,4–0,7 units compared with REG pulse amplitude. They depend on age and are characterized by hemispheric asymmetry. Spectral diagrams of slow fl ucation inside cranium are representing inpendent physiological phenomenon. These fl uctuations are not connected by common origin, with heart activity and respiration. They are connected by nature with brain activity and PRM.Conclusion. Can be an informative method for diagnostic and assessment of general status of osteopathic patients well as for the assessment of mechanisms of action of some osteopathic techniques.


2017 ◽  
Vol 137 (8) ◽  
pp. 481-486
Author(s):  
Junichi Hayasaka ◽  
Kiwamu Shirakawa ◽  
Nobukiyo Kobayashi ◽  
Kenichi Arai ◽  
Nobuaki Otake ◽  
...  

2010 ◽  
Vol 130 (11) ◽  
pp. 1037-1041 ◽  
Author(s):  
Takuma Miyake ◽  
Yuya Seo ◽  
Tatsuya Sakoda ◽  
Masahisa Otsubo
Keyword(s):  

2002 ◽  
Vol 716 ◽  
Author(s):  
Yi-Mu Lee ◽  
Yider Wu ◽  
Joon Goo Hong ◽  
Gerald Lucovsky

AbstractConstant current stress (CCS) has been used to investigate the Stress-Induced Leakage Current (SILC) to clarify the influence of boron penetration and nitrogen incorporation on the breakdown of p-channel devices with sub-2.0 nm Oxide/Nitride (O/N) and oxynitride dielectrics prepared by remote plasma enhanced CVD (RPECVD). Degradation of MOSFET characteristics correlated with soft breakdown (SBD) and hard breakdown (HBD), and attributed to the increased gate leakage current are studied. Gate voltages were gradually decreased during SBD, and a continuous increase in SILC at low gate voltages between each stress interval, is shown to be due to the generation of positive traps which are enhanced by boron penetration. Compared to thermal oxides, stacked O/N and oxynitride dielectrics with interface nitridation show reduced SILC due to the suppression of boron penetration and associated positive trap generation. Devices stressed under substrate injection show harder breakdown and more severe degradation, implying a greater amount of the stress-induced defects at SiO2/substrate interface. Stacked O/N and oxynitride devices also show less degradation in electrical performance compared to thermal oxide devices due to an improved Si/SiO2 interface, and reduced gate-to-drain overlap region.


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