1,353 research outputs found

    CMOS optical-sensor array with high output current levels and automatic signal-range centring

    Get PDF
    A CMOS compatible photosensor with high output current levels, and an area-efficient scheme for automatic signal-range centring according to illumination conditions are presented. The high output current levels allow the use of these devices in continuoustime asynchronous imagers, as well as in high-sampling-frequency applications

    Silicon-germanium BiCMOS device and circuit design for extreme environment applications

    Get PDF
    Silicon-germanium (SiGe) BiCMOS technology platforms have proven invaluable for implementing a wide variety of digital, RF, and mixed-signal applications in extreme environments such as space, where maintaining high levels of performance in the presence of low temperatures and background radiation is paramount. This work will focus on the investigation of the total-dose radiation tolerance of a third generation complementary SiGe:C BiCMOS technology platform. Tolerance will be quantified under proton and X-ray radiation sources for both the npn and pnp HBT, as well as for an operational amplifier built with these devices. Furthermore, a technique known as junction isolation radiation hardening will be proposed and tested with the goal of improving the SEE sensitivity of the npn in this platform by reducing the charge collected by the subcollector in the event of a direct ion strike. To the author's knowledge, this work presents the first design and measurement results for this form of RHBD.M.S.Committee Chair: Cressler, John; Committee Member: Papapolymerou, John; Committee Member: Ralph, Stephe

    A 64-point Fourier transform chip for high-speed wireless LAN application using OFDM

    No full text
    In this article, we present a novel fixed-point 16-bit word-width 64-point FFT/IFFT processor developed primarily for the application in the OFDM based IEEE 802.11a Wireless LAN (WLAN) baseband processor. The 64-point FFT is realized by decomposing it into a 2-D structure of 8-point FFTs. This approach reduces the number of required complex multiplications compared to the conventional radix-2 64-point FFT algorithm. The complex multiplication operations are realized using shift-and-add operations. Thus, the processor does not use any 2-input digital multiplier. It also does not need any RAM or ROM for internal storage of coefficients. The proposed 64-point FFT/IFFT processor has been fabricated and tested successfully using our in-house 0.25 ?m BiCMOS technology. The core area of this chip is 6.8 mm2. The average dynamic power consumption is 41 mW @ 20 MHz operating frequency and 1.8 V supply voltage. The processor completes one parallel-to-parallel (i. e., when all input data are available in parallel and all output data are generated in parallel) 64-point FFT computation in 23 cycles. These features show that though it has been developed primarily for application in the IEEE 802.11a standard, it can be used for any application that requires fast operation as well as low power consumption

    A digitally controlled threshold adjustment circuit in a 0.13um SiGe BiCMOS technology for receiving multilevel signals up to 80Gbps

    Get PDF
    In this paper, a high bandwidth digitally controlled threshold adjustment circuit is proposed which can be used for demodulating high-speed multi-level signals. Simulations of the bandwidth are presented together with measurements of the control currents to indicate the threshold adjustment capability. A bandwidth above 80GHz in a 0.13”m SiGe BiCMOS technology and a threshold tunable between ±160mV in steps of 0.6mV is achieved, allowing very precise control of the threshold level. This allows the circuit to accurately position the threshold on the eye-crossing of a high speed multi-level signals. By applying this circuit to demodulate a duobinary signal over a 40GHz channel, a data rate of up to 80Gbps can be achieved

    A 15-Gbps BiCMOS XNOR gate for fast recognition of COVID-19 in binarized neural networks

    Get PDF
    The COVID-19 pandemic is spreading around the world causing more than 177 million cases and over 3.8 million deaths according to the European Centre for Disease Prevention and Control. The virus has devastating effects on economies, health, and well-being of worldwide population. Due to the high increase in daily cases, the available number of COVID-19 test kits in under-developed countries is scarce. Hence, it is vital to implement an effective screening method of patients using chest radiography since the equipment already exists. With the presence of automatic detection systems, any abnormalities in chest radiography that characterizes COVID-19 can be identified. Several artificial-intelligence algorithms have been proposed to detect the virus. However, neural networks training is considered to be time-consuming. Since computations in training neural networks are spent on floating-point multiplications, high computational power is required. Multipliers consume the most space and power among all arithmetic operators in deep neural networks. This paper proposes a 15 Gbps high-speed bipolar-complementary-metal-oxide-semiconductor (BiCMOS) exclusive-nor (XNOR) gate to replace multipliers in binarized neural networks. The proposed gate can be implemented on BiCMOS-based field-programmable gate arrays (FPGAs). This will significantly improve the response time in identifying chest abnormalities in CT scans and X-rays

    Phase and amplitude pre-emphasis techniques for low-power serial links

    Get PDF
    A novel approach to equalization of high-speed serial links combines both amplitude pre-emphasis to correct for intersymbol interference and phase pre-emphasis to compensate for deterministic jitter, in particular, data-dependent jitter. Phase pre-emphasis augments the performance of low power transmitters in bandwidth-limited channels. The transmitter circuit is implemented in a 90-nm bulk CMOS process and reduces power consumption by pushing CMOS static logic to the output stage, a 4:1 output multiplexer. The received signal jitter over a cable is reduced from 16.15 ps to 10.29 ps with only phase pre-emphasis at the transmitter. The jitter is reduced by 3.6 ps over an FR-4 backplane interconnect. A transmitter without phase pre-emphasis consumes 18 mW of power at 6Gb/s and 600mVpp output swing, a power budget of 3mW/Gb/s, while a transmitter with phase pre-emphasis consumes 24mW, a budget of 4 mW/Gb/s

    Behavior of faulty double BJT BiCMOS logic gates

    Get PDF
    Logic Behavior of a Double BJT BiCMOS device under transistor level shorts and opens is examined. In addition to delay faults, faults that cause the gate to exhibit sequential behavior were observed. Several faults can be detected only by monitoring the current. The faulty behavior of Bipolar (TTL) and CMOS logic families is compared with BiCMOS, to bring out the testability differences

    A monolithic ASIC demonstrator for the Thin Time-of-Flight PET scanner

    Full text link
    Time-of-flight measurement is an important advancement in PET scanners to improve image reconstruction with a lower delivered radiation dose. This article describes the monolithic ASIC for the TT-PET project, a novel idea for a high-precision PET scanner for small animals. The chip uses a SiGe Bi-CMOS process for timing measurements, integrating a fully-depleted pixel matrix with a low-power BJT-based front-end per channel, integrated on the same 100 ÎŒm\mu{} m thick die. The target timing resolution is 30 ps RMS for electrons from the conversion of 511 keV photons. A novel synchronization scheme using a patent-pending TDC is used to allow the synchronization of 1.6 million channels across almost 2000 different chips at picosecond-level. A full-featured demonstrator chip with a 3x10 matrix of 500x500 ÎŒm2\mu{} m^{2} pixels was produced to validate each block. Its design and experimental results are presented here
    • 

    corecore