Design and test of an integrated Sigma–Delta analog-to-digital converter for X-ray Computed Tomography

Author(s):  
Christian Bäumer ◽  
Michael Gnade ◽  
Armin Kemna ◽  
Roger Steadman ◽  
Gereon Vogtmeier ◽  
...  
1999 ◽  
Author(s):  
Frederic Coppinger ◽  
V. Magoon ◽  
A. S. Bhushan ◽  
Bahram Jalali

2016 ◽  
Vol 4 (3) ◽  
pp. 85-90
Author(s):  
Anil Kumar Sahu ◽  
Vivek Kumar Chandra ◽  
G R Sinha

System-level modeling is generally needed due to simultaneous increase in design complexity with multi-million gate designs in today’s system-on-chips (SoCs). System C is generally applied to system-level modeling of Sigma-Delta ADC. CORDIC technique and test generation for the testing of mixed signal circuit components such as analog-to-digital converter is mostly implemented in system level modeling. This work focuses on developing fast and yet accurate model of BIST approach for Sigma-Delta ADC. The Sigma-Delta modulator’s ADC static parameters as well as dynamic parameters are degraded. One of the dynamic parameters, signal-to-noise ratio (SNR) is directly obtained by the SIMSIDES (MATLAB SIMULINK tool). Then, the obtained parameters are tested by using Built-in-self-test that is desirable for the VLSI system in order to reduce the non-recurring cost (NRE) per chip by the manufacturer. This paper demonstrates a possibility to realize a simulation of testing strategy of high-resolution Sigma-Delta modulator using MATLAB SIMULINK and Xilinx EDA tool environment. This work also contributes towards the Output Response Analyzer (ORA) being used for testing parameters which help in reducing the difficulties in design of the complete ORA circuit. Moreover, the reusable features of hardware in the computation of different parameters are also improved in the ORA design.


Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4567
Author(s):  
Mfana ◽  
Hasan ◽  
Ali

Digitization is at the center of fourth industrial revolution (4IR) with previously analog systems being digitized through an analog-to-digital converter. In addition, 4IR applications such as fifth generation (5G) Cellular Networks Technology and Cognitive Electronic Warfare (EW) at some point interface digitally through an analog-to-digital converter. Efficient use of digital resources such as memory, largely depends on the signal sampling design of analog-to-digital converters. Existing even order sampling has been found to perform better than traditional sampling techniques. Research on the efficiency of a digital interface with a 4IR platform is still in its infancy. This paper presents a performance study of three sampling techniques: the proposed new and novel odd/even order sampling architecture, existing Mod-∆, and traditional 1st order delta-sigma, to address this. Step-size signal-to-noise (SNR), dynamic range, and sampling frequency are also studied. It was found that the proposed new and novel odd/even order sampling achieved an SNR performance of 6 dB in comparison to 18 dB for Mod-∆. Sampling frequency findings indicated that the proposed new and novel odd/even order sampling achieved a sampling frequency of 2 kHz in comparison to 8 kHz from a traditional 1st order sigma-delta. Dynamic range findings indicated that the proposed odd/even order sampling has achieved a dynamic range of 1.088 volts/ms in comparison to 1.185 volts/ms from a traditional 1st order sigma-delta. Findings have indicated that the proposed odd/even order sampling has superior SNR and sampling frequency performances, while the dynamic range is reduced by 8%.


2021 ◽  
Vol 6 (2) ◽  
pp. 39-46
Author(s):  
Bao My Nguyen Thi ◽  
Van Sy Nguyen ◽  
Van Tien Vu ◽  
Quang Tuan Ho ◽  
Thuy Mai Nguyen Thi ◽  
...  

X-ray measurement equipment is designed which utilizes a pair of photodiode detectors. The equipment is designed which utilizes a pair of photodiode detectors units which receive X-rays through filters with different attenuation coefficients for X-rays. The photodiode detector units preferably includes two pairs of photodiode detectors arranged symmetrically in four quadrants with the diodes in each detector unit in diagonally opposite quadrants. The outputs of the detector units are passed to variable gain amplifiers, gains of which are adjusted to bring the output voltages within a desired range, and the outputs of the amplifiers are integrated by integrators. After a selected period of time, the integration is stopped and the output voltages of the integrators are held and transmitted to an analog-to-digital converter. The ratio of the two output signals from a pair of photodiode detectors represents the kVp value of the X-ray machine and another pair of photodiode detectors used to measure the relative current in milliamps (mA) and exposure time of the x-ray unit.In this study,  the equipment have been made for measuring the characteristics of X-Ray with an accuracy of kVp (kV), I (mA) is 5% and the 2% T.


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