Low Noise Programmable DC Amplifier with Remote Control

Introduction. In modern experimental technology, the direction associated with the development of information-measuring systems for recording, pre-processing and analyzing excess low-frequency noise (flicker noise) is well known. Currently, such measuring systems are mainly presented in the form of particular solutions, due to the large variety of research goals and objectives. At the same time, for automation of the experiment, multichannel measuring complexes with the possibility of flexible reconfiguration of the measuring channel according to the task are highly demanded. It is obvious that any distributed measuring channel is represented as a multi-stage scheme with given functions and parameters of each stage, which makes it difficult for the measuring system to adapt to different conditions and tasks of the experiment. The logical solution to this problem is a deep unification of all components of the measuring channel while maintaining good performance characteristics. One of the main problems with this is the evaluation of the intrinsic noise of electronic elements, which provide for changing the parameters of the amplifier.Objective. Experimental analysis of the intrinsic noise of electronic potentiometers, development of the concept and study of parameters of a low-noise DC amplifier with a high degree of unification, the possibility of external electronic control and the use of built-in characteristics correction algorithms.Materials and methods. To achieve the set result, a method for measuring the noise of electronic potentiometers was proposed and experimental studies were carried out.Results. According to the calculation results and experimental studies, it was shown that the specific noise of the electronic potentiometers corresponds to the noise of the metal-film resistors, which makes it possible to use them in low-noise amplification stages. The developed circuit solutions allow the implementation of a unified amplifying module with cascading to build low-noise measuring DC paths based on electronic potentiometers. External and internal digital control allows you to significantly improve the performance of the measuring path as a whole and allows you to adapt it to a wide range of tasks.Conclusion. As part of the study, a method was proposed for measuring the noise of electronic potentiometers, analytical and experimental studies were carried out, and a prototype of a low-noise amplifier was developed and investigated.

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Low-frequency noise correlations in lateral pnp bipolar transistors

Canadian Journal of Physics ◽

10.1139/p92-180 ◽

1992 ◽

Vol 70 (10-11) ◽

pp. 1112-1117

Author(s):

A. Nathan ◽

E. Charbon ◽

W. Kung ◽

A. Salim

Keyword(s):

Integrated Circuit ◽

Low Frequency ◽

Intrinsic Noise ◽

Low Noise ◽

Bipolar Transistors ◽

Current Gain ◽

Low Noise Amplifiers ◽

Frequency Noise ◽

Low Frequency Noise ◽

Low Frequencies

Measurement results of low-frequency noise behaviour, and in particular, the noise correlations in lateral pnp bipolar transistors are presented for various bias conditions in both forward active and saturation regimes. The correlation in output collector noise is very high with a value close to unity only when the device is in medium injection. At extremely high injection, the degree of coherence degrades, depicting a behaviour similar to the forward current gain of the device. This degradation can be attributed to emitter-crowding effects. The correlation in output noise can be exploited to drastically suppress the intrinsic noise, particularly at low frequencies, making such devices useful for the input stage of amplifiers; the first step towards realisation of ultra low-noise amplifiers in standard integrated circuit technology.

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LOW FREQUENCY NOISE PARAMETERS IN AN AlGaN/GaN HETEROSTRUCTURE WITH 33% AND 75% Al MOLE FRACTION

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156404002806 ◽

2004 ◽

Vol 14 (03) ◽

pp. 762-768

Author(s):

S. A. VITUSEVICH ◽

S. V. DANYLYUK ◽

N. KLEIN ◽

M. V. PETRYCHUK ◽

A. E. BELYAEV ◽

...

Keyword(s):

Mole Fraction ◽

Flicker Noise ◽

Low Frequency ◽

High Electron Mobility Transistor ◽

Low Noise ◽

Excess Noise ◽

Frequency Noise ◽

High Electron ◽

Low Frequency Noise ◽

Non Linear

Transport and low frequency noise properties of undoped AlGaN/GaN high electron mobility transistor (HEMT) heterostructures with 33% and 75% Al mole fractions in the ohmic and non-linear regimes of applied voltages are studied. In contrast to the low Al mole fraction, the noise properties of 75 % content structures are not affected by passivation. At small voltages both kinds of structures demonstrate about the same level of l/f excess noise. Deviations from conventional flicker noise were observed at high applied voltages. Additionally, differences in noise behaviour between the two structures were revealed. In the 75% content structures, a noise level suppression was registered in the non-linear regime, which is important for the development of low noise oscillator circuits.

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DEDICATED INSTRUMENTATION FOR HIGH SENSITIVITY, LOW FREQUENCY NOISE MEASUREMENT SYSTEMS

Fluctuation and Noise Letters ◽

10.1142/s0219477504001963 ◽

2004 ◽

Vol 04 (02) ◽

pp. L385-L402 ◽

Cited By ~ 23

Author(s):

C. CIOFI ◽

G. GIUSI ◽

G. SCANDURRA ◽

B. NERI

Keyword(s):

Background Noise ◽

Flicker Noise ◽

Low Frequency ◽

High Sensitivity ◽

Design Guidelines ◽

Low Noise ◽

Frequency Noise ◽

Low Frequency Noise ◽

Low Frequencies ◽

Noise Measurements

Low Frequency Noise Measurements (LFNM) can be used as very sensitive tool for the characterization of the quality and the reliability of electron devices. However, especially in those cases in which the frequency range of interest extends below 1 Hz, instrumentation with an acceptable low level of background noise is not easily found on the market. In fact, at very low frequencies, the flicker noise introduced by the electronic components which make up the instrumentation becomes predominant and several interesting phenomena which could be detected by means of LFNM may result completely hidden in the background noise. This consideration is not limited to the case of input preamplifiers but does extend to any piece of instrumentation that contributes to the LFNM systems, and in particular to the power supplies used for biasing the Device Under Test. During the last few years, our research groups have been strongly involved in the design of very low noise instrumentation for application in the field of LFNM. In this work we report the main results which we have obtained together with a discussion of the design guidelines that have allowed us, in a few cases, to reach noise levels not to be equalled by any instrumentation available on the market.

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A Chopper-Embedded BGR Composite Noise Reduction Circuit for Clock Generator

Electronics ◽

10.3390/electronics10182257 ◽

2021 ◽

Vol 10 (18) ◽

pp. 2257

Author(s):

Neeru Agarwal ◽

Neeraj Agarwal ◽

Chih-Wen Lu ◽

Masahito Oh-e

Keyword(s):

Flicker Noise ◽

Noise Analysis ◽

Low Frequency ◽

Low Noise ◽

Frequency Noise ◽

Clock Generator ◽

Low Frequency Noise ◽

Pass Filter ◽

Low Pass Filter ◽

Offset Voltage

A chopper-embedded bandgap reference (BGR) scheme is presented using 0.18 μm CMOS technology for low-frequency noise suppression in the clock generator application. As biasing circuitry produce significant flicker noise, along with thermal noise from passive components, the proposed low-noise chopper-stabilized BGR circuit was designed and implemented for wide temperature range of −40 to 125 °C, including a startup and self-biasing circuit to reduce critical low-frequency noise from the bias circuitry and op amp input offset voltage. The BGR circuit generated a reference voltage of 1.25 V for a supply voltage range of 2.5–3.3 V. The gain of the implemented BGR operational transconductance amplifier is 84.1 dB. A non-overlapping clock circuit was implemented to reduce the clock skew effect, which is also one of the noise contributors. The noise analysis of a chopped bandgap voltage reference was evaluated through cadence periodic steady-state (PSS) analysis and periodic noise (PNoise) analysis. The low-frequency flicker noise was reduced from 1.5 to 0.4 μV/sqrt(Hz) at 1 KHz, with the proposed chopping scheme in the bandgap. Comparisons of the noise performance of the chopper-embedded BGR, with and without a low-pass filter, were also performed, and the results show a further reduction in the overall noise. A reduction in the flicker noise, from 181.3 to 10.26 mV/sqrt(Hz) at 100 KHz, was observed with the filter. All circuit blocks of the proposed BGR scheme were designed and simulated using the EDA tool HSPICE, and layout generation was carried out by Laker. The BGR architecture layout dimensions are 285.25 μm × 125.38 μm.

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Ultra low-noise preamplifier for low-frequency noise measurements in electron devices

IEEE Transactions on Instrumentation and Measurement ◽

10.1109/19.69939 ◽

1991 ◽

Vol 40 (1) ◽

pp. 2-6 ◽

Cited By ~ 55

Author(s):

B. Neri ◽

B. Pellegrini ◽

R. Saletti

Keyword(s):

Low Frequency ◽

Low Noise ◽

Frequency Noise ◽

Low Frequency Noise ◽

Noise Measurements ◽

Electron Devices ◽

Ultra Low Noise ◽

Low Noise Preamplifier

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Low Frequency Vibration Isolation Through an Active-on-Active Approach: Coupling Effects

Journal of Vibration and Acoustics ◽

10.1115/1.4000477 ◽

2009 ◽

Vol 131 (6) ◽

Cited By ~ 2

Author(s):

Qiao Sun ◽

Robert A. Wolkow ◽

Mark Salomons

Keyword(s):

Vibration Isolation ◽

Low Frequency ◽

Noise Cancellation ◽

Frequency Noise ◽

Active Stage ◽

Coupling Effects ◽

Active Approach ◽

Low Frequency Vibration ◽

Wide Range ◽

Coupling Characteristics

The extreme sensitivity of a scanning probe microscope demands an exceptional noise cancellation device that could effectively cut off a wide range of vibration noise. Existing commercial devices, although excellent in canceling high frequency noise, commonly leave low frequency vibration unattenuated. We design an add-on active stage that can function together with a standalone existing active stage. The objective is to provide a higher level of noise cancellation by lowering the overall system cut-off frequency. This study is concerned with the theoretical aspects of the coupling characteristics involved in stacking independently designed stages together to form a two-stage isolator. Whether an add-on stage would pose a stability threat to the existing stage needs to be addressed. In addition, we explore the use of coupling effects to optimize the performance of the overall system.

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A Low-Power Opamp-Less Second-Order Delta-Sigma Modulator for Bioelectrical Signals in 0.18 µm CMOS

Sensors ◽

10.3390/s21196456 ◽

2021 ◽

Vol 21 (19) ◽

pp. 6456

Author(s):

Fernando Cardes ◽

Nikhita Baladari ◽

Jihyun Lee ◽

Andreas Hierlemann

Keyword(s):

Low Power ◽

Low Frequency ◽

Cmos Technology ◽

Low Noise ◽

Second Order ◽

Frequency Noise ◽

Voltage Controlled Oscillator ◽

Noise Shaping ◽

Delta Sigma Modulator ◽

Delta Sigma

This article reports on a compact and low-power CMOS readout circuit for bioelectrical signals based on a second-order delta-sigma modulator. The converter uses a voltage-controlled, oscillator-based quantizer, achieving second-order noise shaping with a single opamp-less integrator and minimal analog circuitry. A prototype has been implemented using 0.18 μm CMOS technology and includes two different variants of the same modulator topology. The main modulator has been optimized for low-noise, neural-action-potential detection in the 300 Hz–6 kHz band, with an input-referred noise of 5.0 μVrms, and occupies an area of 0.0045 mm2. An alternative configuration features a larger input stage to reduce low-frequency noise, achieving 8.7 μVrms in the 1 Hz–10 kHz band, and occupies an area of 0.006 mm2. The modulator is powered at 1.8 V with an estimated power consumption of 3.5 μW.

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Low-Frequency Noise Evaluation on a Commercial Magnetoimpedance Sensor at Submillihertz Frequencies for Space Magnetic Field Detection

Sensors ◽

10.3390/s19224888 ◽

2019 ◽

Vol 19 (22) ◽

pp. 4888

Author(s):

Tao Wang ◽

Chen Kang ◽

Guozhi Chai

Keyword(s):

Magnetic Field ◽

Low Frequency ◽

Temperature Stability ◽

Space Missions ◽

Low Noise ◽

Integration Time ◽

Frequency Noise ◽

Low Frequency Noise ◽

Field Detection ◽

Measurement Limit

The purpose of this study was to measure the low-frequency noise and basic performance of a commercial magnetoimpedance (MI) sensor at sub-millihertz frequencies for use in space missions. Normally, space missions require measuring very weak magnetic fields with a long integration time, such as the space gravitational wave detection mission requiring sub-millihertz frequencies. We set up a platform for measuring the performance on this MI sensor, including low-frequency noise, measurement limit, linearity, and temperature stability. The results show that the low-frequency noise of the MI sensor is below 10 nT/√Hz at 1 mHz and below 100 nT/√Hz at 0.1 mHz; its measurement limit is 600 pT. The MI sensor is characterized by high precision, small size, and low noise, demonstrating considerable potential for application in magnetically sensitive experiments requiring long integration time. This is an effect way to solve the problem that there is on one suitable magnetic sensor at space magnetic field detection, but the sensor requires improvements in temperature stability.

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Low-Frequency Noise and Microplasma Analysis for c-Si Solar Cell Characterization

International Journal of Photoenergy ◽

10.1155/2012/324853 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Jiří Vanek ◽

Jan Dolensky ◽

Zdenek Chobola ◽

Mirek Luňák ◽

Aleš Poruba

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Conversion Efficiency ◽

Low Frequency ◽

Low Noise ◽

Frequency Noise ◽

Noise Spectral Density ◽

Selective Emitter ◽

Noise Spectroscopy ◽

Cell Conversion

This paper brings the comparison of solar cell conversion efficiency and results from a noise spectroscopy and microplasma presence to evaluate the solar cell technology. Three sets of monocrystalline silicon solar cells (c-Si) varying in front side phosphorus doped emitters were produced by standard screen-printing technique. From the measurements it follows that the noise spectral density related to defects is of 1/ftype and its magnitude. It has been established that samples showing low noise feature high-conversion efficiency. The best results were reached for a group solar cells with selective emitter structure prepared by double-phosphorus diffusion process.

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