457 research outputs found
Investigation of the RTN Distribution of nanoscale MOS devices from subthreshold to on-state
This letter presents a numerical investigation of the statistical distribution of the random telegraph noise (RTN) amplitude in nanoscale MOS devices, focusing on the change of its main features when moving from the subthreshold to the on-state conduction regime. Results show that while the distribution can be well approximated by an exponential behavior in subthreshold, large deviations from this behavior appear when moving toward the on-state regime, despite a low probability exponential tail at high RTN amplitudes being preserved. The average value of the distribution is shown to keep an inverse proportionality to channel area, while the slope of the high-amplitude exponential tail changes its dependence on device width, length, and doping when moving from subthreshold to on-state
Performance optimization of detector electronics for millimeter laser ranging
The front-end electronic circuitry plays a fundamental role in determining the performance actually obtained from ultrafast and highly sensitive photodetectors. We deal here with electronic problems met working with microchannel plate photomultipliers (MCP-PMTs) and single photon avalanche diodes (SPADs) for detecting single optical photons and measuring their arrival time with picosecond resolution. The performance of available fast circuits is critically analyzed. Criteria for selecting the most suitable electronics are derived and solutions for exploiting the detector performance are presented and discussed
A Multi-Channel Low-Power System-on-Chip for in vivo NeuralSpike Recording
This paper reports a multi-channel neural spike
recording system-on-chip (SoC) with digital data compression
and wireless telemetry. The circuit consists of a 64-channel
low-power low-noise analog front-end, a single 8-bit analog-todigital
converter (ADC), followed by digital signal compression
and transmission units. The 400-MHz transmitter employs a
Manchester-Coded Frequency Shift Keying (MC-FSK) modulator
with low modulation index. In this way a 1.25-Mbit/s data
rate is delivered within a band of about 3 MHz. Compression of
the raw data is implemented by detecting the action potentials
(APs) and storing 20 samples for each spike waveform. The choice
greatly improves data quality and allows single neuron identification.
A larger than 10-m transmission range is reached with
an overall power consumption of 17.2 mW. This figure translates
into a power budget of 269 μW per channel, which is in line
with the results in literature but allowing a larger transmission
distance and more efficient wireless link bandwidth occupation.
The implemented IC was mounted on a small and light printed
circuit board to be used during neuroscience experiments with
freely-behaving rats. Powered by 2 AAA batteries the system can
work continuously for more than 100 hours allowing long-lasting
neural spike recordings
Fundamental Power Limits of SAR and ΔΣ Analog-to-Digital Converters
This work aims at estimating and comparing the power limits of ΔΣ and charge-redistribution successiveapproximation register (CR-SAR) analog-to-digital converters (ADCs), in order to identify which topology is the most powerefficient for a target resolution. A power consumption model for mismatch-limited SAR ADCs and for discrete-time (DT) ΔΣ modulators is presented and validated against experimental data.
SAR ADCs are found to be the best choice for low-to-medium resolutions, up to roughly 80 dB of dynamic range (DR). At high resolutions, on the other hand, ΔΣ modulators become more power-efficient. This is due to the intrinsic robustness of the ΔΣ modulation principle against circuit imperfections and nonidealities.
Furthermore, a comparison of the area occupation of such topologies reveals that, at high resolutions and for a given dynamic range, ΔΣ ADCs result more area-efficient as well
How to squeeze high quantum efficiency and high time resolution out of a SPAD
We address the issue whether Single-Photon Avalanche Diodes (SPADs) can be suitably designed to achieve a trade-off between quantum efficiency and time resolution performance. We briefly recall the physical mechanisms setting the time resolution of avalanche photodiodes operated in single-photon counting, and we give some criteria for the design of SPADs with a quantum efficiency better than l0 percent at 1064 nm together with a time resolution below 50 ps rms
Possible link between Hashimoto's thyroiditis and oral lichen planus: a novel association found
none5Lo Muzio L.; Santarelli A.; Campisi G.; Lacaita MG.; Favia G.Lo Muzio, L.; Santarelli, Andrea; Campisi, G.; Lacaita, M. G.; Favia, G
Transient currents in HfO2 and their impact on circuit and memory applications
We investigate transient currents in HfO2 dielectrics, considering their dependence on electric field, temperature and gate stack composition. We show that transient currents remain an issue even at very low temperatures and irrespective of the HfO2/SiO2 bilayer properties. Finally, we assess their impact on the reliability of precision circuit and memory applications
Transient currents in HfO2 and their impact on circuit and memory applications (PDF Download Available). Available from: http://www.researchgate.net/publication/224672970_Transient_currents_in_HfO2_and_their_impact_on_circuit_and_memory_applications [accessed Oct 22, 2015]
Crosstalk calibration of multi-pixel photon counters using coherent states
We present a novel method of calibration of crosstalk probability for
multi-pixel photon counters (MPPCs) based on the measurement of the normalized
second-order intensity correlation function of coherent light. The method was
tested for several MPPCs, and was shown to be advantageous over the traditional
calibration method based on the measurements of the dark noise statistics. The
method can be applied without the need of modification for different kinds of
spatially resolved single photon detectors.Comment: 8 pages, 3 figures, 2 table
A Multi-Channel Low-Power System-on-Chip for in Vivo Recording and Wireless Transmission of Neural Spikes
This paper reports a multi-channel neural spike recording system-on-chip with digital data compression and wireless telemetry. The circuit consists of 16 amplifiers, an analog time-division multiplexer, a single 8 bit analog-to-digital converter, a digital signal compression unit and a wireless transmitter. Although only 16 amplifiers are integrated in our current die version, the whole system is designed to work with 64, demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. Compression of the raw data is achieved by detecting the action potentials (APs) and storing 20 samples for each spike waveform. This compression method retains sufficiently high data quality to allow for single neuron identification (spike sorting). The 400 MHz transmitter employs a Manchester-Coded Frequency Shift Keying (MC-FSK) modulator with low modulation index. In this way, a 1.25 Mbit/s data rate is delivered within a limited band of about 3 MHz. The chip is realized in a 0.35 um AMS CMOS process featuring a 3 V power supply with an area of 3.1x 2.7 mm2. The achieved transmission range is over 10 m with an overall power consumption for 64 channels of 17.2 mW. This figure translates into a power budget of 269uW per channel, in line with published results but allowing a larger transmission distance and more efficient bandwidth occupation of the wireless link. The integrated circuit was mounted on a small and light board to be used during neuroscience experiments with freely-behaving rats. Powered by 2 AAA batteries, the system can continuously work for more than 100 hours allowing for long-lasting neural spike recordings
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