scholarly journals Noise Considerations of Integrators for Current Readout Circuits

2005 ◽  
Vol 3 ◽  
pp. 331-336 ◽  
Author(s):  
B. Bechen ◽  
A. Kemna ◽  
M. Gnade ◽  
T. v. d. Boom ◽  
B. Hosticka

Abstract. In this paper the noise analysis of a current integrator is carried out and measures to reduce the overall noise are presented. The effects of various noise sources are investigated and their dependence on the input capacitance and on the gate area of the input transistors of the OTA used for the readout is shown. Both, input capacitance and gate area, should be kept as small as possible. Moreover, the linearity of the integrator is examined. In addition to that, the available application of such sensor readout circuit, which is a CMOS photodetector readout, is introduced. It uses an automatic gain switching, so that the dynamic range is extended.

2020 ◽  
Vol 10 (3) ◽  
pp. 23
Author(s):  
Wei Wang ◽  
Sameer Sonkusale

Designing low-noise current readout circuits at high speed is challenging. There is a need for preamplification stages to amplify weak input currents before being processed by conventional integrator based readout. However, the high current gain preamplification stage usually limits the dynamic range. This article presents a 140 dB input dynamic range low-noise current readout circuit with a noise floor of 10 fArms/sq(Hz). The architecture uses a programmable bidirectional input current gain stage followed by an integrator-based analog-to-pulse conversion stage. The programmable current gains setting enables one to achieve higher overall input dynamic range. The readout circuit is designed and in 0.18 μm CMOS and consumes 10.3 mW power from a 1.8 V supply. The circuit has been verified using post-layout simulations.


2010 ◽  
Vol 8 ◽  
pp. 129-133
Author(s):  
D. Würfel ◽  
D. Weiler ◽  
B. J. Hosticka ◽  
H. Vogt

Abstract. As state-of-the-art readout circuits short-time integrators in Far Infrared (FIR) uncooled bolometer arrays are commonly used. This paper compares the transfer functions of an ideal continuous-time integrator with that of a real integrator with focus an OTA parameters and noise analysis. Beside the noise sources at the non-inverting input of the OTA special care has to be taken to account for capacitances at the inverting input. The Noise Equivalent Temperature Difference (NETD) as the key parameter for bolometer applications for a real short-time integrator will be derived. As the result it will be shown, that the NETD is 1/f-noise limited.


Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 635
Author(s):  
Chih-Hsuan Lin ◽  
Chao-Hung Song ◽  
Kuei-Ann Wen

In this study, a multi-function microelectromechanical system (MEMS) was integrated with a MEMS oscillator, using the resonant frequency oscillation characteristics of the oscillator to provide the Lorentz current of the magnetometer to enhance a large dynamic range of reading, which eliminates the off-chip clock and current generator. The resonant frequency can be adjusted by adjusting the bias voltage of the oscillator to further adjust the sensitivity of the magnetometer. With the mechanical Q value characteristic, a great dynamic range can be achieved. In addition, using the readout circuit of the nested chopper and correlated double-sampling (CDS) to reduce the noise and achieve a smaller resolution, the calibration circuit compensates for errors caused by the manufacturing process. The frequency of the tuning range of the proposed structure is 17,720–19,924 Hz, and the tuning range of the measurement result is 110,620.36 ppm. The sensitivities of the x-, y-, and z-axes of the magnetometer with driving current of 2 mA are 218.3, 74.33, and 7.5 μV/μT for ambient pressure of 760 torr. The resolutions of the x-, y-, and z-axes of the magnetometer with driving current of 2 mA are 3.302, 9.69, and 96 nT/√Hz for ambient pressure of 760 torr.


2018 ◽  
Vol 41 (3) ◽  
pp. 875-882 ◽  
Author(s):  
Jian-Feng Wu ◽  
Shang-Shang He ◽  
Feng Wang ◽  
Yu Wang ◽  
Xin-Gang Zhao ◽  
...  

In the readout circuits of the two-dimensional (2-D) resistive sensor arrays, various auxiliary electrical components were used to reduce their crosstalk errors but resulted in increased circuit complexity. Readout circuits with low-complexity structures were necessary for wearable electronic applications. With only several resistors and a microcontroller, readout circuit based on resistance matrix approach (RMA) achieved low complexity but suffered from small resistance range and large measurement error caused by the output ports’ internal resistances of the microcontroller. For suppressing those negative effects, we firstly proposed an improved resistance matrix approach (IRMA) by additionally sampling the voltages on all driving row electrodes in the RMA. Then the effects of the output ports’ internal resistances and the analog-to-digital converter’s accuracy for the RMA and the IRMA were simulated respectively with NI Multisim 12. Moreover, a prototype readout circuit based on the IRMA was designed and tested in actual experiments. The experimental results demonstrated that the IRMA, though it required more sampling channels and more computations, could be used in those applications needing low complexity, small measurement error and wide resistance range.


2021 ◽  
Vol 263 (4) ◽  
pp. 2590-2600
Author(s):  
Luiz Henrique Mesa Casa Pereira ◽  
Björn Knöfel ◽  
Jan Troge ◽  
Welf-Guntram Drossel ◽  
Marcel Klein ◽  
...  

Research on the relation between exposure to noise and cognitive performance inside industrial environments is not as broad as on office environments. For a better understanding of the specific industrial noise problems, participants performed arithmetic tests inside a hemi anechoic room while they were exposed to sounds of five typical industrial noise sources. The subjects also classified how annoying they perceived the noise signals. The effect of noise on the arithmetic test's performance was larger on accuracy than on velocity, which was verified using a Student t-test. Spectral-temporal characteristics - especially high frequency content and strong low frequency modulation - appear to relate better with lower performance on the test than high sound levels. Subjects that evaluated noise as more annoying performed worse in a final arithmetic test (under silence) after being exposed to the noises, indicating a possible cumulative effect of noise on performance. The findings provide a better insight in the cognitive behavior of people who are exposed to industrial noise. Hence, the study will proceed with the specific noise analysis of single industrial workplaces.


Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 185 ◽  
Author(s):  
Phillip Durdaut ◽  
Michael Höft ◽  
Jean-Michel Friedt ◽  
Enrico Rubiola

Surface acoustic wave (SAW) sensors in the form of two-port resonators or delay lines are widely used in various fields of application. The readout of such sensors is achieved by electronic systems operating either in an open-loop or in a closed-loop configuration. The mode of operation of the sensor system is usually chosen based on requirements like, e.g., bandwidth, dynamic range, linearity, costs, and immunity against environmental influences. Because the limit of detection (LOD) at the output of a sensor system is often one of the most important figures of merit, both readout structures, i.e., open-loop and closed-loop systems, are analyzed in terms of the minimum achievable LOD. Based on a comprehensive phase noise analysis of these structures for both resonant sensors and delay line sensors, expressions for the various limits of detection are derived. Under generally valid conditions, the equivalence of open-loop and closed-loop operation is shown for both types of sensors. These results are not only valid for SAW devices, but are also applicable to all kinds of phase-sensitive sensors.


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