scholarly journals A Gain Programmable Analog Divider Circuit Based on a Data Converter

2017 ◽  
Vol 7 (6) ◽  
pp. 2251-2255
Author(s):  
S. N. Asl ◽  
M. Tarkhan ◽  
M. S. Nia
Keyword(s):  
Output Signal ◽  
Dynamic Range ◽  
Gain Control ◽  
Data Converters ◽  
Data Converter ◽  
Programmable Analog ◽  
Operation Speed ◽  
Input Signals ◽  
Voltage Signal ◽  
Analog Systems

Analog dividers are widely used in analog systems. Analog realization of such circuits suffer from limited dynamic range and non-linearity issues, therefore, extra circuitry should be required to compensate these types of shortcomings. In this paper a gain controllable, analog divider is proposed based on data converters. Our circuit can be implemented both in current and voltage mode by selecting proper architectures. The resolution, power consumption and operation speed can be controlled by proper selecting of components. Another advantage of our circuit is its gain programmability. Moreover, the gain can be adjusted independently based on the relationship between input signals. Our proposed method offers two different gain control abilities, one for situation that the numerator signal is bigger than the denominator, and another gain is applied when the denominator is larger than the numerator. As a result, no extra amplifier is required for signal amplification. Moreover, the input and output signal nature can be chosen arbitrarily in this circuit, i.e. input signal may be a voltage signal while the output signal is current. Simulation results from SPICE confirm the proper operation of the circuit.

scholarly journals Photodetector resistant to background light noise with extended dynamic range of input signals

2021 ◽  
pp. 3-8
Author(s):  
V. M. Lipka ◽  
V. V. Ryukhtin ◽  
Yu. G. Dobrovolsky
Keyword(s):  
Dynamic Range ◽  
Automatic Gain Control ◽  
Modulation Frequency ◽  
Low Frequency ◽  
Gain Control ◽  
Ambient Air ◽  
Frequency Range ◽  
Background Light ◽  
Useful Signal ◽  
Extended Dynamic

Measurement of periodic optical information signals in the background light noise with a photodetector with extended dynamic range is an urgent task of modern electronics and thus has become the aim of this study. To increase the dynamic range of the photodetector, a new version of the automatic gain control (AGC) circuit has been developed, which consists of an AGC controller, an output photodetector amplifier and an AGC detector. The authors measured the dynamic range of the photodetector when receiving optical radiation with a wavelength of 1064 nm in the power range from 2.10–8 to 2.10–5 W at a modulation frequency of 20 kHz with the AGC on. Under these conditions, the dynamic range of the photodetector was found to be up to 67 dB. If the AGC was off, the dynamic range did not exceed 30 dB. Thus, the study made it possible to create a photodetector with an extended dynamic range up to 67 dB based on a new version of the AGC circuit. The design of the photodetector allowed choosing a useful signal of a particular modulation frequency in the frequency range from 3 to 45 kHz and effectively suppresses the frequencies caused by optical interference in the low frequency range from the frequency of the input signal of constant amplitude up to 3 kHz inclusive. This compensates the current up to 15 mA, which is equivalent to the power of light interference of about 15 mW. Further research should address the issues of reliability of the proposed photodetector design and optimization of its optical system. The photodetector can be used in geodesy and ambient air quality monitoring.

scholarly journals 14.85 µW Analog Front-End for Photoplethysmography Acquisition with 142-dBΩ Gain and 64.2-pArms Noise

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 512
Author(s):  
Binghui Lin ◽  
Mohamed Atef ◽  
Guoxing Wang
Keyword(s):  
Dynamic Range ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Low Noise ◽  
Total Power ◽  
Cmos Process ◽  
Control Block ◽  
Silicon Area ◽  
Front End ◽  
Analog Front End

A low-power, high-gain, and low-noise analog front-end (AFE) for wearable photoplethysmography (PPG) acquisition systems is designed and fabricated in a 0.35 μm CMOS process. A high transimpedance gain of 142 dBΩ and a low input-referred noise of only 64.2 pArms was achieved. A Sub-Hz filter was integrated using a pseudo resistor, resulting in a small silicon area. To mitigate the saturation problem caused by background light (BGL), a BGL cancellation loop and a new simple automatic gain control block are used to enhance the dynamic range and improve the linearity of the AFE. The measurement results show that a DC photocurrent component up-to-10 μA can be rejected and the PPG output swing can reach 1.42 Vpp at THD < 1%. The chip consumes a total power of 14.85 μW using a single 3.3-V power supply. In this work, the small area and efficiently integrated blocks were used to implement the PPG AFE and the silicon area is minimized to 0.8 mm × 0.8 mm.

scholarly journals A Novel Highly Linear Voltage-To-Time Converter (VTC) Circuit for Time-Based Analog-To-Digital Converters (ADC) Using Body Biasing

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2033
Author(s):  
Ahmed Elgreatly ◽  
Ahmed Dessouki ◽  
Hassan Mostafa ◽  
Rania Abdalla ◽  
El-sayed El-Rabaie
Keyword(s):  
Power Consumption ◽  
Software Defined Radio ◽  
Dynamic Range ◽  
Supply Voltage ◽  
Cmos Technology ◽  
The Body ◽  
Analog To Digital Converters ◽  
Clock Frequency ◽  
Analog To Digital ◽  
Operation Speed

Time-based analog-to-digital converter is considered a crucial part in the design of software-defined radio receivers for its higher performance than other analog-to-digital converters in terms of operation speed, input dynamic range and power consumption. In this paper, two novel voltage-to-time converters are proposed at which the input voltage signal is connected to the body terminal of the starving transistor rather than its gate terminal. These novel converters exhibit better linearity, which is analytically proven in this paper. The maximum linearity error is reduced to 0.4%. In addition, the input dynamic range of these converters is increased to 800 mV for a supply voltage of 1.2 V by using industrial hardware-calibrated TSMC 65 nm CMOS technology. These novel designs consist of only a single inverter stage, which results in reducing the layout area and the power consumption. The overall power consumption is 18 μW for the first proposed circuit and 15 μW for the second proposed circuit. The novel converter circuits have a resolution of 5 bits and operate at a maximum clock frequency of 500 MHz.

scholarly journals 10-GHz Fully Differential Sallen–Key Lowpass Biquad Filters in 55nm SiGe BiCMOS Technology

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 563
Author(s):  
Francesco Centurelli ◽  
Pietro Monsurrò ◽  
Giuseppe Scotti ◽  
Pasquale Tommasino ◽  
Alessandro Trifiletti
Keyword(s):  
Communication Systems ◽  
Power Efficiency ◽  
High Speed ◽  
Closed Loop ◽  
Dynamic Range ◽  
Data Converters ◽  
Fully Differential ◽  
Biquad Filter ◽  
Bicmos Technology ◽  
Sige Bicmos

Multi-GHz lowpass filters are key components for many RF applications and are required for the implementation of integrated high-speed analog-to-digital and digital-to-analog converters and optical communication systems. In the last two decades, integrated filters in the Multi-GHz range have been implemented using III-V or SiGe technologies. In all cases in which the size of passive components is a concern, inductorless designs are preferred. Furthermore, due to the recent development of high-speed and high-resolution data converters, highly linear multi-GHz filters are required more and more. Classical open loop topologies are not able to achieve high linearity, and closed loop filters are preferred in all applications where linearity is a key requirement. In this work, we present a fully differential BiCMOS implementation of the classical Sallen Key filter, which is able to operate up to about 10 GHz by exploiting both the bipolar and MOS transistors of a commercial 55-nm BiCMOS technology. The layout of the biquad filter has been implemented, and the results of post-layout simulations are reported. The biquad stage exhibits excellent SFDR (64 dB) and dynamic range (about 50 dB) due to the closed loop operation, and good power efficiency (0.94 pW/Hz/pole) with respect to comparable active inductorless lowpass filters reported in the literature. Moreover, unlike other filters, it exploits the different active devices offered by commercial SiGe BiCMOS technologies. Parametric and Monte Carlo simulations are also included to assess the robustness of the proposed biquad filter against PVT and mismatch variations.

New Voters for Redundant Systems

1975 ◽  
Vol 97 (1) ◽  
pp. 41-45 ◽  
Author(s):  
R. B. Broen
Keyword(s):  
Smooth Function ◽  
Output Signal ◽  
Weighted Average ◽  
Direct Calculation ◽  
Fault Isolation ◽  
Function Approach ◽  
Redundant System ◽  
Isolation System ◽  
Input Signals ◽  
Redundant Systems

This paper describes a class of redundant voters which compute and provide a “correct” output signal given a set of redundant input signals. The output is determined as a continuous smooth function of the redundant inputs using a weighted “average.” This type of voter tends to minimize switching transients since the isolation of faulty signals is achieved through a continuous numerical weighting. Equalization schemes which are normally required in voter designs to inhibit adverse transients during a channel failure are negated by this method. This function approach to designing a voter and fault isolation system provides for direct calculation of the characteristics of the output signal, given known characteristics of the inputs. Using this proposed method, a voter can be designed to provide a weighted average of the remaining good signals of a redundant system in the presence of one or more failed signal channels. Computed examples of voter output for assumed values of voter input signals are given for one representative candidate voter when used in configurations for both triply redundant and quadruply redundant systems.

Technology Research of Digital Closed-Loop Fiber-Optic Gyroscope

2012 ◽  
Vol 241-244 ◽  
pp. 1056-1059 ◽  
Author(s):  
Dong Sheng Yang
Keyword(s):  
Closed Loop ◽  
Fiber Optic ◽  
Dynamic Range ◽  
Light Path ◽  
Fiber Optic Gyro ◽  
Technology Research ◽  
Fiber Optic Gyroscope ◽  
Operation Speed ◽  
Gyroscope System ◽  
Processing Circuit

Digital fiber-optic gyroscope with linear scale factor, phase high accuracy, dynamic range, etc. This article proposed one kind of closed-loop digital fiber optic gyroscope system based on DSP, and designs the closed-loop fiber-optic gyro for signal detection and processing circuit, and the whole digital closed loop of fiber optic gyroscope light path part and circuit of the concrete analysis. With DSP as logic circuit, make the gyro operation speed and reliability have improved greatly.

scholarly journals Detail Enhancement for Infrared Images Based on Propagated Image Filter

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Yishu Peng ◽  
Yunhui Yan ◽  
Jiuliang Zhao
Keyword(s):  
Dynamic Range ◽  
Gain Control ◽  
Bilateral Filter ◽  
Input Image ◽  
Base Layer ◽  
Infrared Images ◽  
Image Filter ◽  
Histogram Modification ◽  
Detail Enhancement ◽  
Infrared Data

For displaying high-dynamic-range images acquired by thermal camera systems, 14-bit raw infrared data should map into 8-bit gray values. This paper presents a new method for detail enhancement of infrared images to display the image with a relatively satisfied contrast and brightness, rich detail information, and no artifacts caused by the image processing. We first adopt a propagated image filter to smooth the input image and separate the image into the base layer and the detail layer. Then, we refine the base layer by using modified histogram projection for compressing. Meanwhile, the adaptive weights derived from the layer decomposition processing are used as the strict gain control for the detail layer. The final display result is obtained by recombining the two modified layers. Experimental results on both cooled and uncooled infrared data verify that the proposed method outperforms the method based on log-power histogram modification and bilateral filter-based detail enhancement in both detail enhancement and visual effect.

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