1,721,077 research outputs found
Analog Circuits and Systems for Voltage-Mode and Current-Mode Sensor Interfacing Applications
No full textOne-Decade Frequency Range, In-Phase Auto-Aligned 1.8 v 2 mW Fully Analog CMOS Integrated Lock-In Amplifier for Small/Noisy Signal Detection
No full textIn this paper, we present a new fully analog integrated lock-in amplifier (LIA) for the accurate detection and the measurement of small, slow, and noisy signals, typical of sensors. The proposed LIA, designed as an integrated circuit in a 0.35 \mu \textm standard CMOS technology with low-voltage (1.8 V) low-power (2 mW) characteristics, performs an automatic alignment (auto-calibration) of the relative phase between the input and reference signals, both at power-ON of the system and for any variation during its operating time. Even if these kinds of amplifiers work at a specific single operating frequency at time, the proposed LIA has been optimized to operate, through an automatic frequency tuning function, in one-decade frequency variation range, set to [2.5-25 Hz], particularly affected by flicker noise. On-chip measurements have confirmed the proper functionality of the system in the recovery and amplification of small and noisy signal amplitudes, in particular 714 times lower than the noise level (i.e., signal-To-noise ratio (SNR) of about-57 dB), obtaining an experimental best resolution of 12.5 nV with maximum a sensitivity of about 124 000 [V/V]. Moreover, by means of the employment of the proposed LIA, the experimental SNR and resolution improvements are of a factor of about 4000
Resistive sensors interfacing in : Giant Magnetoresistance (GMR) Sensors From Basis to State-of-the-Art Applications, Smart Sensors, Measurement and Instrumentation
No full textAnalog Wheatstone Bridge Based Automatic Interface for Grounded and Floating Wide Range Resistive Sensors
No full textUncalibrated automatic bridge-based CMOS integrated interfaces for wide-range resistive sensors portable applications
No full textHigh-Sensitivity High-Resolution Optical Phase Shift Detection Technique Using a Si Photodiode Operating in Photovoltaic Mode
No full textA novel uncalibrated OA-based sensor interface for capacitive/resistive sensor applications
No full textELECTRICAL SELF-MODULATION OF OPTICAL SENSORS FOR LIGHT POWER MEASUREMENT IN CHEMICAL APPLICATIONS BY PHASE DETECTION TECHNIQUE
No full textA novel 6-decades fully analog uncalibrated Wheatstone bridge-based resistive sensor interface
No full textHigh-Sensitivity Differential Interface for the Detection of Energy Variations of Nanosecond Laser Pulses for Spectroscopic Applications
No full textThis paper reports on a photodiode bridge interface circuit able to perform differential measurements of the energy variations of 10ns laser pulses obtained by differentially detecting the photocurrents generated by a reference and a signal photodiode. A complete characterization of the interface circuit is reported by varying its gain and the energy-per-pulse difference between the signal and the reference laser pulses at a 20Hz operating frequency (i.e., the laser repetition rate). Under these conditions, a maximum detection sensitivity of about 7mV/fJ has been achieved. The functionality of the interface circuit has been tested by detecting the Rhodamine-6G photoluminescence emission after pumping the sample with 10ns laser pulses at a 20Hz repetition rate. In particular, the Rhodamine-6G was diluted in ethanol and the interface circuit has been used to measure the photoluminescence emission as a function of the variations of its molar concentration. The experimental findings demonstrate the possibility to achieve interface circuit sensitivities up to 1225mV/μM corresponding to a minimum detection resolution of 0.8pM with a measured RMS output noise level of about 1μV. It is also reported that these results enhance of more than 3 orders of magnitude the sensitivity achieved by using a standard/commercial lock-in amplifier in a differential measurement configuration
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