A fast lightstripe rangefinding system with smart VLSI sensor

The focus of the research is to build a compact, high performance lightstripe rangefinder using a Very Large Scale Integration (VLSI) smart photosensor array. Rangefinding, the measurement of the three-dimensional profile of an object or scene, is a critical component for many robotic applications, and therefore many techniques were developed. Of these, lightstripe rangefinding is one of the most widely used and reliable techniques available. Though practical, the speed of sampling range data by the conventional light stripe technique is severely limited. A conventional light stripe rangefinder operates in a step-and-repeat manner. A stripe source is projected on an object, a video image is acquired, range data is extracted from the image, the stripe is stepped, and the process repeats. Range acquisition is limited by the time needed to grab the video images, increasing linearly with the desired horizontal resolution. During the acquisition of a range image, the objects in the scene being scanned must be stationary. Thus, the long scene sampling time of step-and-repeat rangefinders limits their application. The fast range sensor proposed is based on the modification of this basic lightstripe ranging technique in a manner described by Sato and Kida. This technique does not require a sampling of images at various stripe positions to build a range map. Rather, an entire range image is acquired in parallel while the stripe source is swept continuously across the scene. Total time to acquire the range image data is independent of the range map resolution. The target rangefinding system will acquire 1,000 100 x 100 point range images per second with 0.5 percent range accuracy. It will be compact and rugged enough to be mounted on the end effector of a robot arm to aid in object manipulation and assembly tasks

Advanced CMOS Integrated Circuit Design and Application

The recent development of various application systems and platforms, such as 5G, B5G, 6G, and IoT, is based on the advancement of CMOS integrated circuit (IC) technology that enables them to implement high-performance chipsets. In addition to development in the traditional fields of analog and digital integrated circuits, the development of CMOS IC design and application in high-power and high-frequency operations, which was previously thought to be possible only with compound semiconductor technology, is a core technology that drives rapid industrial development. This book aims to highlight advances in all aspects of CMOS integrated circuit design and applications without discriminating between different operating frequencies, output powers, and the analog/digital domains. Specific topics in the book include: Next-generation CMOS circuit design and application; CMOS RF/microwave/millimeter-wave/terahertz-wave integrated circuits and systems; CMOS integrated circuits specially used for wireless or wired systems and applications such as converters, sensors, interfaces, frequency synthesizers/generators/rectifiers, and so on; Algorithm and signal-processing methods to improve the performance of CMOS circuits and systems

Low-Noise Energy-Efficient Sensor Interface Circuits

Today, the Internet of Things (IoT) refers to a concept of connecting any devices on network where environmental data around us is collected by sensors and shared across platforms. The IoT devices often have small form factors and limited battery capacity; they call for low-power, low-noise sensor interface circuits to achieve high resolution and long battery life. This dissertation focuses on CMOS sensor interface circuit techniques for a MEMS capacitive pressure sensor, thermopile array, and capacitive microphone. Ambient pressure is measured in the form of capacitance. This work propose two capacitance-to-digital converters (CDC): a dual-slope CDC employs an energy efficient charge subtraction and dual comparator scheme; an incremental zoom-in CDC largely reduces oversampling ratio by using 9b zoom-in SAR, significantly improving conversion energy. An infrared gesture recognition system-on-chip is then proposed. A hand emits infrared radiation, and it forms an image on a thermopile array. The signal is amplified by a low-noise instrumentation chopper amplifier, filtered by a low-power 30Hz LPF to remove out-band noise including the chopper frequency and its harmonics, and digitized by an ADC. Finally, a motion history image based DSP analyzes the waveform to detect specific hand gestures. Lastly, a microphone preamplifier represents one key challenge in enabling voice interfaces, which are expected to play a dominant role in future IoT devices. A newly proposed switched-bias preamplifier uses switched-MOSFET to reduce 1/f noise inherently.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/137061/1/chaseoh_1.pd

Energy-Efficient Circuit Designs for Miniaturized Internet of Things and Wireless Neural Recording

Internet of Things (IoT) have become omnipresent over various territories including healthcare, smart building, agriculture, and environmental and industrial monitoring. Today, IoT are getting miniaturized, but at the same time, they are becoming more intelligent along with the explosive growth of machine learning. Not only do IoT sense and collect data and communicate, but they also edge-compute and extract useful information within the small form factor. A main challenge of such miniaturized and intelligent IoT is to operate continuously for long lifetime within its low battery capacity. Energy efficiency of circuits and systems is key to addressing this challenge. This dissertation presents two different energy-efficient circuit designs: a 224pW 260ppm/°C gate-leakage-based timer for wireless sensor nodes (WSNs) for the IoT and an energy-efficient all analog machine learning accelerator with 1.2 µJ/inference of energy consumption for the CIFAR-10 and SVHN datasets. Wireless neural interface is another area that demands miniaturized and energy-efficient circuits and systems for safe long-term monitoring of brain activity. Historically, implantable systems have used wires for data communication and power, increasing risks of tissue damage. Therefore, it has been a long-standing goal to distribute sub-mm-scale true floating and wireless implants throughout the brain and to record single-neuron-level activities. This dissertation presents a 0.19×0.17mm2 0.74µW wireless neural recording IC with near-infrared (NIR) power and data telemetry and a 0.19×0.28mm2 0.57µW light tolerant wireless neural recording IC.PHDElectrical and Computer EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169712/1/jongyup_1.pd

Wide-Dynamic Range Image Sensor Prototype Based On Digital Readout Integrated Circuit

Emerging infrared and visible imaging applications require higher sensitivity, larger pixel array, larger contrast ratio (dynamic range), very low power consumption and faster data readout rate operations all at the same time. Some of these applications are camera surveillance used both in day/night (very bright and dark conditions), medical diagnostics, weather forecasting, and aerial search & rescue operations etc. The digital-pixel focal plane array (DFPA) implemented in this thesis has the capabilities to capture a wide dynamic range of more than 120dB in a single global shutter without saturating the pixels at a huge frame rate of more than 500Hz. An adaptive Integration Window technique has been developed which ensures that we are able to measure such a huge dynamic range using a counter of only 10 bits (this helps us lower the power consumption of the design). This proposed image sensor has been designed, fabricated and tested in 65nm CMOS technology. It has 16 x 16-pixel array with 16 x 9 pixels with an inbuilt Silicon APD for optical testing and 16 x 7 dummy pixels for electrical testing. Our design proposes an off-chip digital calibration technique to cut down the burden on the analog circuitry. The sensor design achieved more than 128dB+ of dynamic range with a DNL/INL of 0.65/1.65 respectively with a power consumption of only 0.58 uW/pixel. The digital calibration scheme successfully cuts down the pixel-pixel variation standard deviations by a factor of 4. The proposed image sensor design should be able to address most of the short-comings of conventional FPAs and provides a one-shot solution to the design of high performance CMOS image sensors

Integrated circuit & system design for concurrent amperometric and potentiometric wireless electrochemical sensing

Complementary Metal-Oxide-Semiconductor (CMOS) biosensor platforms have steadily grown in healthcare and commerial applications. This technology has shown potential in the field of commercial wearable technology, where CMOS sensors aid the development of miniaturised sensors for an improved cost of production and response time. The possibility of utilising wireless power and data transmission techniques for CMOS also allows for the monolithic integration of the communication, power and sensing onto a single chip, which greatly simplifies the post-processing and improves the efficiency of data collection. The ability to concurrently utilise potentiometry and amperometry as an electrochemical technique is explored in this thesis. Potentiometry and amperometry are two of the most common transduction mechanisms for electrochemistry, with their own advantages and disadvantages. Concurrently applying both techniques will allow for real-time calibration of background pH and for improved accuracy of readings. To date, developing circuits for concurrently sensing potentiometry and amperometry has not been explored in the literature. This thesis investigates the possibility of utilising CMOS sensors for wireless potentiometric and amperometric electrochemical sensing. To start with, a review of potentiometry and amperometry is evaluated to understand the key factors behind their operation. A new configuration is proposed whereby the reference electrode for both electrochemistry techniques are shared. This configuration is then compared to both the original configurations to determine any differences in the sensing accuracy through a novel experiment that utilises hydrogen peroxide as a measurement analyte. The feasibility of the configuration with the shared reference electrode is proven and utilised as the basis of the electrochemical configuration for the front end circuits. A unique front-end circuit named DAPPER is developed for the shared reference electrode topology. A review of existing architectures for potentiometry and amperometry is evaluated, with a specific focus on low power consumption for wireless applications. In addition, both the electrochemical sensing outputs are mixed into a single output data channel for use with a near-field communication (NFC). This mixing technique is also further analysed in this thesis to understand the errors arising due to various factors. The system is fabricated on TSMC 180nm technology and consumes 28µW. It measures a linear input current range from 250pA - 0.1µW, and an input voltage range of 0.4V - 1V. This circuit is tested and verified for both electrical and electrochemical tests to showcase its feasibility for concurrent measurements. This thesis then provides the integration of wireless blocks into the system for wireless powering and data transmission. This is done through the design of a circuit named SPACEMAN that consists of the concurrent sensing front-end, wireless power blocks, data transmission, as well as a state machine that allows for the circuit to switch between modes: potentiometry only, amperometry only, concurrent sensing and none. The states are switched through re-booting the circuit. The core size of the electronics is 0.41mm² without the coil. The circuit’s wireless powering and data transmission is tested and verified through the use of an external transmitter and a connected printed circuit board (PCB) coil. Finally, the future direction for ongoing work to proceed towards a fully monolithic electrochemical technique is discussed through the next development of a fully integrated coil-on-CMOS system, on-chip electrodes with the electroplating and microfludics, the development of an external transmitter for powering the device and a test platform. The contributions of this thesis aim to formulate a use for wireless electrochemical sensors capable of concurrent measurements for use in wearable devices.Open Acces

An optical telemetry system for wireless transmission of biomedical signals across the skin

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Vita.Includes bibliographical references (p. 236-239).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.A technology base for optically-coupled systems was developed that permits in-vivo transmission of biomedical signals across the skin. By complete implantation of sensors and instrumentation electronics, problems with percutaneous connectors were eliminated. Optical power and signal transmission was accomplished with smaller and lighter implant structures than previously achieved with radio frequency (RF) coupling techniques. This is particularly valuable in the field of neuroprosthetics, because it may be possible to implant an optical telemeter directly on the surface of the brain to make mechanically stable connections to microelectrode arrays for neuroelectric recordings. Miniature optical power panels (2.5 mm x 2.5 mm) were developed from arrays of photodiodes. Infrared light of 880 nm wavelength was effective for delivering power across the skin. Panels composed of silicon photodiodes were 14% efficient at converting this light to electrical power, and GaAlAs panels were 41% efficient. Tissue heating experiments demonstrated the safety of optical power transmission. An LED was identified that was both electrically efficient (16%) and of appropriate wavelength (660 nm) for transmitting optical signals from the implant. Pulse period encoding was used for transmission of signals because it was robust and required less power than schemes with higher LED duty cycles. Specialized photodetector circuits were developed to receive pulse encoded data, and decoder circuits were built to reconstruct the transmitted signals. Two prototype single-channel neural waveform telemeters (approx. 10 Hz to 7 kHz bandwidth) were constructed and implanted in the visual cortex of rabbits. Both implants successfully transmitted neuroelectric signals. The first implant survived for four weeks before failing due to a flaw in the encapsulation, and the improved second prototype continues to function properly 28 months after implantation. Integrated circuits (ICs) were designed to record and transmit eight channels of neural waveforms. The first IC telemeter functioned properly, although the sensitivity was not as great as needed for the recording of neural waveforms. It required less than 50 mW of electrical power to operate. Efforts to improve this design introduced flaws in the next set of IC designs, so these problems were addressed, and a final set of designs was submitted for fabrication at the conclusion of this research project.by Bruce C. Larson.Ph.D

Exploration of advanced CMOS technologies for new pixel detector concepts in High Energy Physics

This thesis presents the author’s original concepts for the development of radiation hard monolithic pixel sensors that can replace hybrid pixel sensors in high energy physics experiments. It presents one of the first practical implementations of monolithic pixel sensors that potentially offer performance figures similar to those of the hybrid pixel technology with fewer material and for a fraction of the cost. Various pixel sensor prototypes in different technologies have been designed and manufactured for the first time. Prototypes allowed the characterization of the basic components of active pixel sensors and the evaluation of device parameters. Presented devices show strong indications that monolithic sensors can achieve very high radiation tolerance with parameters similar to the existing hybrid technology. Other application areas like X-ray imaging may also benefit from this development

Superconducting single-photon and photon-number-resolving detectors

Detecting light of low intensity is a key requirement in many fields of scientific endeavor, including but not limited to quantum information science, astronomy and optical spectroscopy. In the past decade the progress in the technology of superconducting film has allowed the realization of a new type of detector based on ultrathin (4-5nm) and narrow

Integrating detectors and their application to infrared astronomy

The work contained in this thesis is concerned with the performance of infrared integrating detector arrays, within the context of astronomical spectroscopy.A linear array of thirty-two InSb photo diodes is investigated. It is found to exhibit good capacitance and dark current uniformity across the array. By applying the principle of charge conservation to the multiplexed readout arrangement of this device, the signal response of the detector to different levels of illumination is derived. It is found from this, and confirmed experimentally, that the device has a highly linear radiation response over a range of reverse biases.The interaction between dark current and photo-current is studied,primarily by the application of a simple model. The results indicate that the effective signal gain of a detector can vary in the situation where dark current dominates the discharge processes, since in this instance accurate dark current subtraction becomes difficult.The predictions of the model are compared with experiments performed on two integrating arrays; one under study in the laboratory,and the other installed in the low background environment of a cooled grating spectrometer. Finally, suggestions are presented of ways of avoiding this problem, the simplest of which involves utilizing, where possible, low dark current detector materials.The importance of achieving good dark current uniformity with arrays is stressed, since this will improve the ability to flat-field faint object spectra.To illustrate the importance of these devices, infrared spectra obtained with array detectors, covering a range of astronomical objects,are presented and discussed