Peak Hold Circuit Research Articles

A low-power AE b-value sensor for structural health monitoring

An increase in the quantity of aging infrastructure has become a major social issue. It is thus necessary to properly maintain and manage aging infrastructure, which incurs increasingly large maintenance costs. Therefore, there is a demand for maintenance and management using low-cost and wide-application technologies such as Internet of Things (IoT). We propose a unique, ultra-low-power acoustic emission b-value sensor for structural health monitoring. Acoustic emission (AE) is an elastic wave generated by crack generation or growth inside a material. The characteristics of AE, such as waveform, source frequency, source location, and velocity, can indicate damage affecting material strength. When focusing on the source frequency, the b-value, which is the slope of AE amplitude-frequency distribution derived from the source frequency, is important and widely used as an indicator of material integrity. The proposed sensor was developed to detect this b-value trend more conveniently than ever and to achieve continuous structural or machinery health monitoring. We pursued two key points: ultra-low power consumption and long-distance wireless transmission, which enabled the AE sensor to be applied as an IoT sensor. The wake-on-AE algorithm, which wakes the sensor when AE waves reach the sensor, enables AE sensing to consume a very low current of 172μA on two dry batteries. Generally, the waveform of AE is very short in duration, such as microseconds to milliseconds. If the sensor did not wake up and take measurements in such a short time, the AE wave would pass, and the sensor would fail to measure AE. Therefore, we developed a unique analog- digital co-circuit technology that uses a peak-hold circuit to extract AE features with less sampling. In addition, sensor edges reduce data rates through statistical analysis and transmit data using low-power wide-area networks. In this paper, we present validation results obtained with the sensor on bearings. We performed validation experiments with faulty and normal bearings, generating AEs with different b-values. The developed sensor, operated with two dry batteries, and the AE measurement systems for verification simultaneously acquired the AE generated by the bearing rotation. As a result, we successfully confirmed that the developed sensor provides almost the same results as conventional AE systems in b-value measurement with ultra-low power consumption.

Nanosecond Peak Detect and Hold Circuit With Adjustable Dynamic Range

Nanosecond Peak Detect and Hold Circuit With Adjustable Dynamic Range

A CMOS Integrator-Based Clock-Free Time-to-Digital Converter for Home-Monitoring LiDAR Sensors.

This paper presents a nine-bit integrator-based time-to-digital converter (I-TDC) realized in a 180 nm CMOS technology for the applications of indoor home-monitoring light detection and ranging (LiDAR) sensors. The proposed I-TDC exploits a clock-free configuration so as to discard clock-related dynamic power consumption and some notorious issues such as skew, glitch, and synchronization. It consists of a one-dimensional (1D) flash TDC to generate coarse-control codes and an integrator with a peak detection and hold (PDH) circuit to produce fine-control codes. A thermometer-to-binary converter is added to the 1D flash TDC, yielding four-bit coarse codes so that the measured detection range can be represented by nine-bit digital codes in total. Test chips of the proposed I-TDC demonstrate the measured results of the 53 dB dynamic range, i.e., the maximum detection range of 33.6 m and the minimum range of 7.5 cm. The chip core occupies the area of 0.14 × 1.4 mm2, with the power dissipation of 1.6 mW from a single 1.2-V supply.

Speaker Identification for Business-Card-Type Sensors

Human collaboration has a great impact on the performance of multi-person activities. The analysis of speaker information and speech timing can be used to extract human collaboration data in detail. Some studies have extracted human collaboration data by identifying a speaker with business-card-type sensors. However, it is difficult to realize speaker identification for business-card-type sensors at low cost and high accuracy because of spikes in the measured sound pressure data, ambient noise in the non-speaker sensor, and synchronization errors across each sensor. This study proposes a novel sound pressure sensor and speaker identification algorithm to realize speaker identification for business-card-type sensors. The sensor extracts the user's speech at low cost and high accuracy by employing a peak hold circuit and time synchronization module for spike mitigation and precise time synchronization. The algorithm identifies a speaker with high accuracy by removing ambient noise. The evaluations show that the algorithm accurately identifies a speaker in a multi-person activity considering varying numbers of users, environmental noises, and reverberation conditions as well as long or short utterances. In addition, the peak hold circuit enables accurate extraction of speech and the synchronization error between the sensors is always within $\pm$ 30 $\boldsymbol\mu$ s, that is, negligible error.

A CMOS Peak Detect and Hold Circuit With Auto-Adjust Charging Current for NS-Scale Pulse ToF Lidar Application

This paper presents a novel CMOS peak detect and hold (PDH) circuit scheme for pulsed time of flight (ToF) Lidar application. The proposed PDH circuit, which is one part of analog front end (AFE) circuit of Lidar receiver, is used to widen the narrow input pulse width, aiming to easily digitize the pulse amplitude through a low-speed and low-cost ADC in pulsed ToF Lidar application. The reset voltage clamped to the common-mode level of the input pulse voltage is beneficial to reduce the pedestal error voltage. Meanwhile, the auto-adjust charging current scheme is employed to decrease the peak error through rejecting the overshoot voltage in the proposed PDH circuit. The circuit was implemented and fabricated in a 65-nm CMOS technology. The proposed PDH circuit can detect the pulse voltage with a pulse amplitude range from ~20 mV to ~500 mV and a minimum pulse width of 5 ns. The measured results show that the maximum absolute and relative errors are less than 16 mV and 4.5%, respectively. The layout area of the proposed PDH circuit is equal to 0.17 × 0.14 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

A full sample-type magneto-impedance (MI) magnetometer with programmable circuit for high compatibility

In this study, a programmable Magneto-Impedance (MI) sensor circuit has been designed by using a Field-Programmable-Gate-Arrays (FPGA), and an operational amplifier integrator has been used to replace the peak hold circuit in the conventional system to sample the entire output of the sensor. Since there is no need to adjust the sampling timing to match different MI sensor’s outputs, it is more suitable for mass production than conventional circuits. It was also found that the output of the sensor has the same sensitivity on the rising and falling edges of the excitation current. The output of two parts of the sensor is sampled by an asynchronous sampling frequency, and the noise level of the system proposed is reduced. In comparison with the conventional system, the proposed system in this work has higher sensitivity and lower noise level when utilizing the same sensor, so it might be applied to the bio-medical signal measurement in the future.

A 66-dB Linear Dynamic Range, 100-dB·$\Omega$ Transimpedance Gain TIA With High-Speed PDSH for LiDAR

A wide dynamic range (DR) receiver for the linear pulsed light detection and ranging (LiDAR) is presented, including a high linear DR transimpedance amplifier (TIA) with digital codes to vary its gain and a high-speed peak detector sample and hold (PDSH) circuit to capture the peak value of echo pulses. In order to extend the linear DR without reducing the bandwidth, a source follower is introduced to turn the common-gate amplifier into a large swing current mirror amplifier, leading to stable and low input impedance and three programmable transimpedance gain modes. For improving the precision of the PDSH circuit, a variable current source is utilized to replace the rectifying current mirror to alleviate the overshoot and pedestal voltage error. Implemented in 0.18- $\mu \text{m}$ standard CMOS technology, the proposed TIA achieves a high linear DR of 66 dB with a wide bandwidth of 110 MHz, and the highest gain reaches 100 dB· $\Omega $ . The error of PDSH circuit is less than 0.4% for 70-ns peaking width pulses with amplitude from 100 mV to 1.1 V. The receiver chip consumes 21 mW with a single 3.3-V supply, where the TIA and PDSH consume 8 and 13 mW, respectively.

A Novel Self-Powered Lightning Current Measurement System

To address the lack of reliable power supplies for lightning current measurement systems (LCMS), this paper proposes a novel self-powered LCMS. The required operation power of a LCMS can be provided by harvesting the surge current that is measured using a power coil such that the system can be energized to complete a single-cycle measurement and data recording. In this manner, the stand-alone LCMS is triggered by lightning currents, and, hence, the signal acquisition can be activated automatically. In particular, this paper designs a two-channel passive peak-holding circuit as a low-power substitution to the conventional high-speed sampling modules. The polarity, current peak, and trigger time can be measured and ultimately be stored in a nonvolatile memory. The theoretical and simulation studies are presented in detail to determine the structure, size, and number of winding turns of the power and signal coils. The circuitry design of the power supply and signal conditioning units are also addressed. Experimental results verify that the proposed LCMS can accurately measure the amplitudes of lightning currents, achieving an accuracy of a maximum error of 4%, while the LCMS is fully self-powered to satisfy the energy demand from the measurement and data acquisition tasks.

Design of readout electronics based on peak-holding circuit and multiplexer for a fast neutron spectrometer

Fast neutron detection is meaningful in many research fields such as space environment monitoring. A scintillating fiber array model for fast neutron detection was proposed and developed in 1980s. Aerospace applications of the model require electronics in small size. To design a dedicated electronic system to readout and process the 384-channel signals from scintillating fiber array, and to use the designed system to fabricate a neutron detector for aerospace applications. With the method of nuclear recoil, fast neutron is detected by tracking recoil proton of n–p scatter in scintillating plastic fibers. Using the peak-holding circuits and multiplexers, the system size and power consumption were reduced. The detector fabricated with the designed system, had 34 cm $$\times $$ 34 cm $$\times $$ 27 cm mechanical size, 20.4 kg weight, and 30.05 W power consumption. Comparing to traditional waveform sampling electronics, the designed electronics was highly integrated and had a small size. The readout electronics also gave a better energy resolution of 39% in neutron detection, while the energy resolution was 43% in previous version. In this study, a highly integrated readout electronic system was designed and verified. The detector using the system gave good performance. The designed electronics had potential development in fast neutron detection and other high energy physics detection system.

Axial Signal Analysis and Image Reconstruction in Acoustic Lens Photoacoustic Imaging System

The lateral imaging characteristic of an acoustic lens is similar to the well-known object-image relationship of an optical lens. In this paper, axial signal analysis is carried on and reconstruction methods for a sample's axial photoacoustic (PA) image are researched based on the acoustic-lens PA imaging system. The integral and envelope methods are both proposed to reconstruct a sample's axial PA image, which has only been achieved approximately by the PA signals' peak values obtained by a peak-holding circuit in previous reports. And the envelope method is proposed for the first time. Hilbert transform was used to obtain the envelope of the sample's PA signals and axial PA images. Simulation results show that the integral method is appropriate for low frequency samples, and that the envelope reconstruction method can provide low frequency information of the PA images of samples. So for a sample, it would be best to combine the two methods together.

감마선용 고속 피크홀드회로의 개발

감마선용 고속 피크홀드회로의 개발

Readout electronics for a high-resolution soft X-ray spectrometer based on silicon drift detector

The readout electronics for a prototype soft X-ray spectrometer based on silicon drift detector (SDD), for precisely measuring the energy and arrival time of X-ray photons is presented in this paper. The system mainly consists of two parts, i.e., an analog electronics section (including a pre-amplifier, a signal shaper and filter, a constant fraction timing circuit, and a peak hold circuit) and a digital electronics section (including an ADC and a TDC). Test results with X-ray sources show that an energy dynamic range of 1–10 keV with an integral nonlinearity of less than 0.1% can be achieved, and the energy resolution is better than 160 eV @ 5.9 keV FWHM. Using a waveform generator, test results also indicate that time resolution of the electronics system is about 3.7 ns, which is much less than the transit time spread of SDD (<100 ns) and satisfies the requirements of future applications.

The Method of Dynamic Measurement in Light Distribution Performance Test

&lt;p class="p0"&gt;In order to realize the measurement of dynamic light, a new measurement method of dynamic gain adjustment was proposed in this paper. And the method is combined hardware with software by the programmable amplifier with microprocessor. The value of signal peak is stayed by the peak hold circuit to be reference for gain amplifier. The test speed of dynamic light source is increased greatly through using this method. The dynamic source light can be measured in real-time by programmable gain instrument amplifier which is controlled by microprocessor. The result shows that the measurement error can be reduced to 0.1% in range of the light intensity at 1cd- 2400cd by this method.&lt;/p&gt;

A New Design of Laser Pulse Receiver in the Automatic Control System

The existing problem of current laser pulse receiving system is that the laser pulses width is too narrow to be directly collected. And the consistency of the four signals acquisition is very strict. To deal with these problems, a new design of laser pulse receiver will be introduced in this article. This laser pulse receiving system includes the following structures: new high-speed laser pulse receiving hardware based on CPLD and Four-Quadrant Detectors, new peak-hold circuit of laser pulse, high-speed parallel ADC system, and processing data with fast interpolation algorithm in a Floating-Point DSP. Through the new design of high-speed parallel ADC system, the receiving system is able to simultaneously complete the timing of four high-speed laser pulse signals acquisition and the storing of data. The new construction of high-speed parallel acquisition is a core module in this design. And a new flow how to the DSP handle the data with fast interpolation algorithm will also be introduced in this article.

Wide bandwidth and high precision power supply noise detector by using dual peak detection sample and hold circuits

SUMMARYIn this paper, we proposed a high‐performance, high‐precision power supply noise (PSN) detector by using dual peak detection sample and hold circuits with source follower. By using dual peak detection sample and hold circuits, we can avoid PSN missing detection and therefore avoid massive PSN detection error. We also added one dummy switch to cancel the charge injection effect and to improve the PSN detection accuracy. In the proposed design, we applied one PMOS type charging circuit to enhance the operation frequency of differential amplifier, which can widen both the PSN detection bandwidth and the detection range. As a result, in the proposed PSN detection circuit, the PSN detection bandwidth can be raised from 1 GHz to 2 GHz with the PSN detection error lowered to ±3%. Moreover, the PSN detection range is widened from 10%–50%VDD to 5%–65%VDD as compared with the state‐of‐the‐art design. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Noise distribution of a peak track and hold circuit

Noise in linear electronic circuits is well characterised in terms of power spectral density in the frequency domain and the Normal probability density function in the time domain. For instance a charge preamplifier followed by a simple time independent pulse shaping circuit produces an output with a predictable, easily calculated Normal density function. By the Ergodic Principle this is true if the signal is sampled randomly in time or the experiment is run many times and measured at a fixed time after the circuit is released from reset. Apart from well defined cases, the time of the sample after release of reset does not affect the density function.If this signal is then passed through a peak track-and-hold circuit the situation is very different. The probability density function of the sampled signal is no longer Normal and the function changes with the time of the sample after release of reset. This density function can be classified by the Gumbel probability density function which characterises the Extreme Value Distribution of a defined number of Normally distributed values. The number of peaks in the signal is an important factor in the analysis. This issue is analysed theoretically and compared with a time domain noise simulation programme. This is then related to a real electronic circuit used for low-noise X-ray measurements and shows how the low-energy resolution of this system is significantly degraded when using a peak track-and-hold.

Design and Integration of a High Accuracy Multichannel Analog CMOS Peak Detect and Hold Circuit for APD-Based PET Imaging

This paper presents the design of a high accuracy multichannel peak detect and hold (PDH) circuit. This PDH measures the energy of an event and is one part of a readout chain for avalanche photo diodes (APD)-based positron emission tomography (PET) imaging. The circuit is designed in a 0.35μm CMOS process. The proposed PDH is dedicated to ultra low amplitude, large amplitude range from several tens millivolts to 1.1 V, and fast peaking time (190 ns) semi-Gaussian pulses. The two-phase technique has been used to cancel the major error source of the classical CMOS PDH: offset. A two-gain OTA is applied to minimize the DC error. A peak error less 1% for a small input signal (amplitude is between 40 mV and 300 mV) and a peak error less than 0.2% for a large input signal (amplitude is between 300 mV and 1.1 V) have been obtained from test. The area of a PDH is equal to about 200 μm × 40 μm. In our PDH system, the drop rate is negligible.

Emission Spectral Tomography With Optical Fiber Bundle

The real time acquisition of the optical radiation information of multi points in free space is a difficult problem for the optical fluid fields testing. Traditional data acquisition systems are based on multichannel charge coupled device (CCD), with which the optical radiation information from multi directions can be obtained. However these systems are hard to fit the requirement of parallel beam imaging, and hence bring great errors of inverse computations. A multichannel real time data acquisition system based on a digital signal processor (DSP) and a number of optical fiber bundles (OFBs) is proposed in this paper for fluid field reconstructions. Each OFB unit can acquire the optical radiation information that transmits into its entrance aperture via a sensor unit consisting of an optical fiber coupler and a phototransistor. The DSP acts as a main controller that switches on the exposure of all phototransistors synchronously based on the mechanism of electronic shutter. The synchronous sensed signals are locked by a peak hold circuit and then outputted to analog-to-digital converters (ADCs), and therefore the real time acquisition of the optical radiation information of multi points in free space can be realized, which offers the original parallel beam imaging data for the fluid field reconstructions.

Development of a low-noise, two-dimensional amplifier array

This paper describes the recent development of a low-noise, two-dimensional analog front-end ASIC for hybrid pixel imaging detectors. Based on the Open-IP LSI project, the ASIC is designed to meet a low-noise requirement of better than 100 e - (rms) with self-triggering capability. The ASIC is intended for the readout of pixel sensors utilizing silicon (Si) and cadmium telluride (CdTe) as detector materials for spectroscopic imaging observations in the X-ray and gamma-ray regions. The readout chip consists of a 4 × 4 matrix of identical 270 μ m × 270 μ m pixel cells and was implemented with TSMC 0.35 - μ m CMOS technology. Each pixel cell contains a charge-sensitive amplifier, pole-zero cancellation circuit, shaper, comparator, and peak hold circuit. Preliminary testing of the ASIC achieved an 88 e - (rms) equivalent noise charge and a 25 e - / pF noise slope with power consumption of 150 μ W per pixel.

Highly segmented detector arrays for studying the resonant decay of unstable nuclei

Resonant spectroscopy of short-lived nuclei produced in nucleus–nucleus collisions can provide information on the nature of the nuclear surface and the formation of clusters. Detection of these resonant decays requires detector arrays with good energy and angular resolution. This newest generation of detector array is typically comprised of silicon strip detectors with several hundred to several thousand independent segments. As a key issue of such arrays is the processing of their signals, we report on the development of a non-ASIC system designed to simplify the analog processing and readout from a highly segmented silicon detector array. The non-ASIC system called MASE (multiplexed analog shaper electronics) focuses on providing good energy resolution and adequate timing information for up to 4096 channels. It consists of 16-channel boards which can be either used independently or as part of a larger system. The analog portion of each channel has low and high gain shapers with associated leading edge discriminators and peak hold circuits. The logic for readout of the analog signals is performed by two FPGA chips located on each board. Readout of MASE channels is multiplexed. Logical signals are transferred via LVDS while the analog signals are sequenced into a multisampling ADC. Signals are also multiplexed for inspection purposes. Shaper gains and discriminator thresholds are adjustable through DACs via a USB interface.