Multi-channel Application Specific Integrated Circuit Research Articles

A multi-channel peripheral nerve stimulator with integrate-and-fire encoding

Activation of peripheral nervous system (PNS) fibres to produce variable tactile and proprioceptive sensations in advanced bidirectional prosthetic limbs relies on neural stimulators with high spatial selectivity, dynamic range and resolution. A multi-channel application-specific integrated circuit (ASIC) is developed for PNS fibre activation using a wide dynamic range (10 nA–5 mA), high-resolution (30 nA step, 100 ns pulse accuracy) current stimulator, dissipating 0.73–2.75 mW at 3 V. The ASIC also enables encoding of external pressure signals via an integrate-and-fire methodology. Electrophysiological data of compound nerve action potentials were recorded for a range of stimulus amplitudes and pulse widths. This data was used to benchmark the performance of the ASIC with a known neural stimulator.

Advanced Readout Electronics System for Portable Cosmic Ray Muon Detection

Ground cosmic ray muon measurements have extensive applications in weather and climate change prediction and muon tomography. However, for comprehensive understanding of the relationship between cosmic ray muon and various weather phenomena, the cosmic ray muon flux needs to be determined accurately at various geographical locations. Toward this objective, this report presents an advanced readout electronics system with a multichannel application-specific integrated circuit (ASIC) chip for a portable cosmic ray muon detector. This ASIC chip consists of high-speed comparators and an excellent time-resolution digital circuit module. Furthermore, it can provide all-digital outputs associated with the flux and zenith angles of incident cosmic ray muons. A 32-channel prototype readout ASIC chip was designed and fabricated in a 180-nm mixed-signal CMOS process, and the chip size was 3.9 mm2. A double-layer plastic scintillator muon detector was used to test the performance of this chip. The time resolution of the chip was approximately 5 ns, and its power consumption was only 1.6 mW/channel. Compared with the existing muon readout electronics system, the proposed system has advantages such as low cost, low power, high reliability, small size, and lightweight and is highly suitable for portable real-time cosmic ray muon detection. The final version of this chip will be used to construct a ground cosmic ray muon measurement network for long-term monitoring of cosmic ray muon flux variations around the world.

Application of the multichannel front-end chip for SiPM-based gamma detector

A prototype of a multichannel application specific integrated circuit(ASIC)analog front-end chip was recently developed at the Department of Microelectronics in MEPhI for SiPM-based applications[1]. The chip designed as an analog front-end for the detectors using scintillation crystals NaI(Tl) or CsI(Tl) coupled with a SiPM photosensor.The chip can be used to build multichannel systems in such fields as nuclear science, medical imaging and homeland security.

Multichannel neural recording system based on family ASICs processed in submicron technology

In this paper we present a measurement system for in vivo multichannel recordings of the electrophysiological activity of brain tissue. The system consists of penetrating Microelectrode Array (MEA), three versions of a Conditioning Module each equipped with different Application Specific Integrated Circuits (ASIC), Digitizer and PC Application for recorded data presentation and storage. The MEA consists of 64 15μm diameter microelectrodes. The multichannel ASICs amplify and filter field and action potential signals. The custom-made Digitizer Module simultaneously acquires data from all channels with a 14kS/s sample rate and 12bit resolution. The resulting byte stream (about 2MB/s) is transmitted to the PC via USB (Universal Serial Bus). Eventually the measurement data is decoded, presented to the system user and stored on a HDD. Preliminary system tests confirm its excellent performance (low input refereed noise, low power consumption, low area occupancy, ability of Action Potentials/Local Field Potentials separation). Our system equipped with multichannel ASICs meets requirements of many different neurobiology experiments.

A multichannel ASIC for the tracking system of the CBM experiment

A 128-channel application specific integrated circuit (ASIC) for asynchronous reading and processing the signals of silicon microstrip detectors is presented. The ASIC was designed for operation in a tracking system of the CBM (Compressed Baryonic Matter) International Experiment at the FAIR Accelerating Complex (Darmstadt, Germany). The microcircuit was developed using the CMOS 0.18-μm process of the UMC (Taiwan) and fabricated with the help of the Europractice. The article describes the structure of the ASIC, the operation of the main units, and presents the results of simulation and laboratory investigation of prototype samples.

Low Power, High Dynamic Range Analogue Multiplexer for Multi-Channel Parallel Recording of Neuronal Signals Using Multi-Electrode Arrays

Low Power, High Dynamic Range Analogue Multiplexer for Multi-Channel Parallel Recording of Neuronal Signals Using Multi-Electrode ArraysIn the paper we present the design and test results of an integrated circuit combining a sample&hold circuit and an analogue multiplexer. The circuit has been designed as a building block for a multi-channel Application Specific Integrated Circuit (ASIC) for recording signals from alive neuronal tissue using high-density micro-electrode arrays (MEAs). The design is optimised with respect to critical requirements for such applications, i.e. short sampling time, low power dissipation, good linearity and high dynamic range. Presented design comprises sample&hold circuits with class AB operational amplifier, novel shift register, which allows minimising cross-coupling of the clock signal and control logic. The circuit has been designed in 0.35μm CMOS process and has been successfully implemented in a prototype multi-channel ASIC.

Readout ASICs for silicon drift detectors

Semiconductor drift detectors (SDDs) are widely used in X-ray spectroscopy due to their excellent performances in terms of energy resolution and detection-rate. Suitable low noise readout electronics have to be designed in order to exploit the SDD intrinsic performances. The integration of this electronics in custom application specific integrated circuits (ASICs) is mandatory when the compactness of the detection system (detector and electronics) and the need to read out multi-elements SDDs are primary requirements. This work describes the development of three circuits for SDDs, which are a charge sensitive preamplifier operating in the pulsed reset regime, a fast shaping amplifier for high-count rates applications and a multi-channel ASIC that provides the whole analog processing and multiplexing of the signals from SDD arrays. The ASICs have been tested with SDDs with on-chip JFET and the results are presented here.

Spatial Distribution Measurement of Ions Surrounding an Alpha Source using a New Micro-ionization Chamber

Recently, a new alpha radioactivity measurement technique was proposed, which directly measures ions surrounding alpha radioactivity. In order to implement this technique, a better understanding of ion's behavior is required. We have developed a micro-ionization chamber with multi-channel charge-integrating ASICs (Application Specific Integrated Circuit). In this study, we will introduce the design of the micro-ionization chamber and show first results from ion measurements using an 241 Am alpha source. When we increase the electric field, the spatial distribution of ions exhibited two different components. Simulation calculations were also performed to account for these components.

A readout ASIC for SPECT

A new low-noise multichannel application specific integrated circuit (ASIC) has been designed for use in nuclear medical imaging single photon emission computed tomography (SPECT), and prototypes have been produced and tested. The ASIC has 128 charge sensitive amplifiers (CSAs) followed by shapers, threshold discriminators, and sample-and-hold. The ASIC delivers analog signal amplitude and digital address from channels with signals above threshold, and optionally allows one to read signals from any channel using a random-access readout. The total power consumption is 358 mW. The ASIC parameters have been specified and measured as follows: each amplifier can measure charge within a linear dynamic range from -40000 e to +40000 e. The preamplifier noise is 56 e+11.6 e/pF at 10 /spl mu/s shaping time. The ASIC is ideally suited for readout of radiation sensors with a few pF capacitance and less than 100 pA dc input current. The ASIC has been tested with silicon diode pad sensors: the diode had a capacitance of /spl ap/1 pF and a leakage current of 20 pA. We measure an equivalent noise charge of 85 e, and achieve a triggering threshold of 800 e. Energy spectra from radioactive isotopes have been measured with energy resolution of 823 eV FWHM for 5.9 keV X-rays.

Spatial Distribution Measurement of Ions Surrounding an Alpha Source using a New Micro-ionization Chamber

Recently, a new alpha radioactivity measurement technique was proposed, which directly measures ions surrounding alpha radioactivity. In order to implement this technique, a better understanding of ion's behavior is required. We have developed a micro-ionization chamber with multi-channel charge-integrating ASICs (Application Specific Integrated Circuit). In this study, we will introduce the design of the micro-ionization chamber and show first results from ion measurements using an 241 Am alpha source. When we increase the electric field, the spatial distribution of ions exhibited two different components. Simulation calculations were also performed to account for these components.

Development of a multi-channel waveform sampling ASIC for animal PET with DOI information

A detector module for high-resolution animal PET with depth-of-interaction (DOI) information has been proposed. It consists of finely granulated scintillators individually coupled to each pixel of a multi-array Avalanche Photodiode. Scintillators of different decay times are stacked as in a phoswich detector to provide DOI information by pulse shape discrimination. Since each channel will be readout individually for high sensitivity and spatial resolution, a power efficient and highly integrated multi-channel Waveform Sampling Front-End (WSFE) Application Specific Integrated Circuit (ASIC) have been developed. Each channel of the WSFE ASIC consists of a preamplifier, a variable gain amplifier and a fast Analog to Digital Converter to digitize signals at an early stage.

A high performance multi-channel preamplifier ASIC

A novel preamplifier application-specific integrated circuit (ASIC) has been designed and built to improve performance of the Vertex Time Projection Chamber (VTPC) at the Fermilab Colliding Detector Facility (CDF). Design of the semicustom IC was completed using a Tektronix QuickChip 2S bipolar linear array. The ASIC has six channels on a chip and provides lower noise, higher gain, lower power, and lower mass packaging than the device which it replaces. Actual performance of the preamplifier was found to match very closely the simulated performance. To reduce the mass of the complete circuit board, bare IC dice were mounted directly on a G-10 substrate using chip on board techniques. >