Discrete Integrated Circuits Research Articles

Smart Sensor Framework: A Pressure Sensor for Smart Home Applications

Smart home automation applications require a dense information network for proper func-tionality. Air-conditioning or filtration systems, for example, must detect airflows caused by openwindows and doors. An unambiguous detection of such airflows can be performed by a distributedsensor network. Current off-the-shelf sensors often lack processing and communication units, resulting in a large design assembly of discrete integrated circuits (ICs) on one printed circuit board (PCB)that requires additional power supply. Distributing such designs within a home without interferingwith the existing surroundings proves to be difficult in terms of acceptance and usability. This paperpresents a solution by offering an integrated design that includes a microelectromechanical system(MEMS) pressure sensor element along with an analog to digital converter (ADC) and a customizableand programmable processing unit. The integration leads to a smaller overall footprint and reducedpower consumption, which positively affects the acceptance rate of distributed smart sensor networksfor home automation. Clear interfaces between the components ensure an extensible and adaptablesystem design suitable for further smart sensor applications, resulting in a smart sensor framework.

An Evaluation of an Integrated On-Chip/Off-Chip Network for High-Performance Reconfigurable Computing

As the number of cores per discrete integrated circuit (IC) device grows, the importance of the network on chip (NoC) increases. However, the body of research in this area has focused on discrete IC devices alone which may or may not serve the high-performance computing community which needs to assemble many of these devices into very large scale, parallel computing machines. This paper describes an integrated on-chip/off-chip network that has been implemented on an all-FPGA computing cluster. The system supports MPI-style point-to-point messages, collectives, and other novel communication. Results include the resource utilization and performance (in latency and bandwidth).

A biopsy tool with integrated piezoceramic elements for needle tract cauterization and cauterization monitoring

This paper reports the feasibility of biopsy needle tract cauterization and cauterization monitoring using an embedded array of piezoceramic microheaters. Circular heaters of lead zirconate titanate (PZT-5A), with 200μm diameter and 70-80μm thickness, are fabricated using a batch mode micro ultrasonic machining process. These are then assembled into cavities in the walls of 20-gauge stainless steel needles and sealed with epoxy. Experiments are performed by inserting the proposed biopsy needle into porcine tissue samples. The needle surface exceeds the minimum target temperature rise of 33°C for either radial or thickness mode vibrations. The corresponding input power levels are 236mW and 325mW, respectively. The tissue cauterization extends 1-1.25mm beyond the perimeter of the needle and is uniform in all directions. After cauterization, the fundamental anti-resonance frequency and the corresponding impedance magnitude of the PZT heater decrease by 4.1% and 42.6%, respectively, thereby providing a method to monitor the extent of tissue cauterization. A sensing interface circuit capable of measuring the resonance frequency shift of the PZT elements is built and tested using discrete integrated circuit components. The circuit detects the resonance frequency shift from 8.22MHz to 7.96MHz of the PZT elements when the biopsy needle is inserted into wax medium. An interface circuit for actuation of the PZT elements for tissue cauterization is also described.

피에조일렉트릭 프린터 헤드 구동을 위한 집적화된 고전압 펄스 발생 회로의 설계

This paper presents an integrated variable amplitude high voltage pulse generation circuit with low power and small size for driving industrial piezoelectric printer heads. To solve the problems of large size and power overhead of conventional pulse generators that usually assembled with multiple high-cost discrete ICs on a PCB board, we have designed a new integrated circuit (IC) chip. Since all the functions are integrated on to a single-chip it can achieve low cost and control the high-voltage output pulse with variable amplitudes as well. It can also digitally control the rising and falling times of an output high voltage pulse by using programmable RC time control of the output buffer. The proposed circuit has been designed and simulatedd in a 180[nm] Bipolar-CMOS-DMOS (BCD) technology using HSPICE and Cadence Virtuoso Tools. The proposed single-chip pulse generation circuit is suitable for use in industrial printer heads requiring a variable high voltage driving capability.

Novel pseudo-exponential circuits

In this paper, two voltage-mode circuits that implement the pseudo-exponential function using controllable gain blocks are presented. The gain block of the proposed circuits each utilize a current conveyor and an operational amplifier in a novel manner. They offer the advantages that they are precise, easily implemented in integrated circuit (IC) form and can employ a bank of switched resistors, MOS transistors in triode or transconductors to change their gain according to a control parameter /spl chi/ that is determined by a ratio of resistances. Experimental results using discrete IC components confirm the theory and show the circuits having an output range of approximately 22 dB, with an error of less than 1 dB for x greater than -0.55 and less than 0.63.

Robust speed control of a switched reluctance vector drive using variable structure approach

The robust speed control of a switched reluctance vector drive is presented in this paper. An approximate sliding-mode input power controller and another feedforward sliding-mode speed controller are combined with space voltage vector modulation. The resultant drive has rapid and robust speed response. In addition, a switched reluctance motor (SRM) drive incorporating the proposed controller requires only one current sensor and can be implemented in a low-cost 8-bit microcomputer and a few discrete integrated circuits. Furthermore, the controller does not require any offline characterization of the motor or load characteristics and could easily be applied to SRMs with any number of phase windings. A 4 kW four-phase SRM drive is constructed to test the performance of the controller. The results show that a step response from 200 to 1980 RPM needs only 2-3 s, even when driving a high-inertia load, and that the speed error can be controlled below 1%, even under unknown and dynamic loads. It is concluded that modified sliding-made controllers are effective in dealing with the highly-nonlinear characteristics of the SRM drive system.