An on-chip temperature sensor by utilizing a MOS tunneling diode

A simple metal-oxide-semiconductor (MOS) tunneling diode was demonstrated for application to an integrated temperature sensor. The MOS diode equipped with a 21-Å oxide was biased inversely at 1.8 V to monitor its substrate temperature through gate current. The gate current increased more than 700 times when the diode was heated from 20 to 110°C. An exponential fitting curve correlated the gate current and the substrate temperature. Moreover, characteristics of the diode were analyzed though C-V and I_{1.8 V}-n_i curves. The good temperature response of the MOS tunneling diode might be useful in self-diagnosis or self-protection IC applications     

A high precision temperature control system for CMOS integrated wide range resistive gas sensors

In this work we present an integrated interface for wide range resistive gas sensors able to heat the sensor resistance through a constant power heater block at 0°C–350°C operating temperatures. The proposed temperature control system is formed by a sensor heater (which fixes the sensor temperature at about 200°C), a R/f (or R/T) converter, which converts the resistive value into a period (or frequency), and can be able to reveal about 6 decades variation (from 10 KΩ up to 10 GΩ), and a digital subsystem that control the whole systems loop. This interface allows high sensibility and precision and performs good stability in temperature and power supply drift and low power characteristics so it can be used also in portable applications. Test measurements, performed on the fabricated chip, have shown an excellent agreement between theoretical expectations and simulation results. Giuseppe Ferri is an associate professor in Electronics at the Department of Electrical Engineering of L’ Aquila University, Ital. In 1993 he has been a visiting researcher at SGS-Thomson Milano, working in bipolar low-voltage op-amp design. In 1994-95 he has been visiting researcher at KU Leuven working in low-voltage CMOS design in the group of Prof. Sansen. His research activity is actually centred on the analog design of integrated circuits for portable applications (e.g., sensors and biomedicals) and circuit theory. He is co-author of a book entitled “Low Voltage, Low Power CMOS Current Conveyors”, Kluwer ed. (2003) and four text-books in Italian on Analogue Microelectronics (2005, 2006). Moreover, he is author and co-author of 74 papers on international and Italian journals and 123 talks at national and international conferences. Vincenzo Stornelli was born in Avezzano (AQ), Italy, on May 31, 1980. He received the Electronics Engineering degree (cum laude) in July 2004. In October 2004 he joined the Department of Electronic Engineering, University of L’Aquila, where he is actually involved with problems concerning project and design of integrated circuits for RF and sensor applications, CAD modelling, characterization, and design analysis of active microwave components, circuits, and subsystems. He regularly teaches courses of the European Computer patent and has regular collaborations with national corporations such as Thales Italia     

高速宽温度范围无致冷DFB半导体激光器

报道了一种高性能的1.3μm波长的应变多量子阱分布反馈半导体激光器,它具有高的直接调制速率、宽的无致冷工作温度范围以及可靠性能好的特点.通过对激光器有源区、波导层以及DFB光栅结构的综合优化,所制作的激光器具有低的阈值电流以及高的量子效率,其室温直接调制速率达到16GHz,能实现-40℃～85℃范围内无致冷工作,其中值寿命超过200万小时.     

一种宽范围电压探测器的设计

以耗尽型ＮＭＯＳ管构成参考电压,通过激光修整,调节有关电阻的阻值和ＭＯＳ管的栅长,设计了一种探测范围很广的电压探测器。ＳＰＩＣＥ模拟表明,该电压探测器具有功耗低、温度漂移低、精确度高的特点。     

Power analysis and design of wide dynamic range CMOS imaging sensors

Wide dynamic range (WDR) CMOS imaging sensors (CIS) are being designed for new portable, implantable and sensory applications, which demand low power consumption. Compared to normal CISs, high quality WDR CISs generally consume much more power. Up to now, the power consumption of a WDR CIS has never been formally studied. This paper focuses to model and analyze the power consumption of two major WDR CIS designs. Analytical equations are derived for the WDR CIS power, and are verified with HSPICE simulations. The analysis indicates that the power consumption of WDR CISs is dominated by the column bus driving power for large imaging array, while photocurrent related power is negligible. Hence, the WDR CIS power is heavily dependent on the load of the column bus and the read-out frequency. A new partial quantization scheme is developed to acquire WDR images with greatly reduced read-out frequencies. Its power consumption is also analytically derived and verified with HSPICE simulations. A 256×256 partial quantization column consumes about 124.0 nW/pixel in the CMOS process for 16-bit dynamic range and 30 Hz frame rate. The power analysis is further verified by experimental measurements of a proof-of-concept 32×32 partial quantization imaging sensor in the CMOS process.     

An on-chip back-bias generator for MOS dynamic memory

An on-chip back-bias generator for 64K dynamic MOS RAM has been developed.The use of this generator achieves the goal of a single 5 V power supply part while preserving the advantages of substrate bias in n-channel MOS technology. These advantages include the elimination of substrate injection current from localized forward biasing of diodes, improved speed and power characteristics, and a larger differential data signal on the bit sense lines. The generator circuit avoids several pit-falls on on-chip V/SUB BB/ generation. The circuit pumps to a known regulated voltage. This avoids substrate drift with changes in substrate current resulting from changes in cycle time. This drift will change device characteristics and degrade storage levels. A unique two-level reference scheme avoids changes in substrate bias voltage that otherwise result from the shift in V/SUB BB/ between precharged and active memory states when memory duty cycle changes. The standby power used by the generator is only 0.74 mW.     

A wide range linear variable resistor by buried channel MOS/SIMOX

A low-distortion linear variable resistor using an offset gate buried-channel MOSFET fabricated by SIMOX technology is described. The offset gate structure on the insulating substrate provides 15 to 100 k/spl Omega/ drain-to-source resistance, and 2.5% total harmonic distortion at 100 k/spl Omega/. In a battery-feed circuit application for a subscriber-line interface circuit, the area of a variable conventional polysilicon resistor.     

High frequency wide range CMOS analogue multiplier

A new CMOS analogue cell which can be used to implement a four-quadrant multiplier circuit is introduced. Simulation results of the circuit using the MOSIS 2 mu m process parameters are given. The circuit has an input range of +or-4 V and linearity error less than 1% for inputs up to +or-3 V. The magnitude and phase response are very flat; even at 30 MHz the change in the magnitude is less than 0.086 dB (1%) and the phase shift is less than 5 degrees .<>     

Engineering model of MOS transistors for the 60-300 K temperature range

The authors present the first engineering model of short-channel MOS transistors that is applicable to cryogenic CMOS. The new model incorporates the nonuniversal dependence of the effective channel mobility on the effective vertical field which is ignored in the room temperature device models. The proposed model is verified by comparison with experimental device characteristics obtained over a wide range of temperatures and channel lengths.<>     

Post-CMOS electrode formation and isolation for on-chip temperature-controlled electrochemical sensors

A low-cost post-CMOS fabrication process enabling the formation of thermally controlled and isolated microelectrode array sites suitable for biomimetic and bioelectronic protein attachment on existing CMOS circuitry has been developed and implemented in the fabrication of an electrochemical array system for biosensing applications.     

Low-noise silicon carbide X-ray sensor with wide operating temperature range

A silicon carbide (SiC) sensor is presented with high energy resolution in X-ray spectroscopy over a wide temperature range (27-100/spl deg/C). The sensor, consisting of a Schottky barrier diode on high resistivity epitaxial SiC, is characterised by an extremely low noise due to its ultra-low reverse current density even at high operating temperature (15 pA/cm/sup 2/ at 27/spl deg/C and 0.5 nA/cm/sup 2/ at 100/spl deg/C). Equivalent noise charges as low as 17 electrons rms at 27/spl deg/C and 47 electrons rms at 100/spl deg/C have been measured, allowing X-ray spectroscopy with an energy resolution as low as 315 eV and 797 eV FWHM, respectively.     

铝电解电容器的宽温高频低阻抗特性研究

以宽温高频低阻抗特性的理论为基础,实验分析了该类特性的低压电解电容器应用无水或多水电解液体系的利弊,以及乙二醇多水体系水能改善低温特性的原因。结果表明:EG-水混合溶剂体系低压电解液,φ(水)在20%～50%,γ30℃大于10–3S·cm–1时,才可满足宽温高频要求。此类低压电解电容器的高温指标能达到105℃负荷寿命3000h的水平。     

宽测温范围高温节点CC2530的开发

底层代码开源的CC2530节点芯片,在煤田火区无线传感器监测大规模组网中更具优势。针对CC2530节点不具有SPI接口的情况,利用USART接口引脚模拟了SPI接口,采用32位MAX31855与K型热电偶的模数转换,通过编写时钟片选、数据传输、时序及主从引脚配置的控制软件,开发了测温范围-40℃～1000℃的高温CC2530无线传感器网络节点。火焰、沸水、冰块的温度测试实验表明,编写的控制软件正确地转换和处理了热电偶的模拟电压量,模拟SPI口稳定地传输数据,为宽范围的温度监测需求提供可选项。     

折/衍混合红外物镜超宽温度消热差设计

利用折/衍混合透镜实现了超宽温度范围内的光学被动式消热差设计,系统工作波段为8～12μm,全视场角为9.15°,焦距为100mm,相对孔径为1/1.5,总长为128mm,后工作距为10.5 mm.使用了锗和硒化锌两种材料,采用三片透镜,衍射面和偶次非球面的引入,不但能够消除热差,而且使得结构简单、轻量化,很好地提高了成...     

MOSFET electron inversion layer mobilities-a physically basedsemi-empirical model for a wide temperature range

A physically based semiempirical model for electron mobilities of the MOSFET inversion layers that is valid over a large temperature range (77 K⩽T⩽370 K) is discussed. It is based on a reciprocal sum of three scattering mechanisms, i.e. phonon, Coulomb, and surface roughness scattering, and is explicitly dependent on temperature and transverse electric field. The model is more physically based than other semiempirical models, but has an equivalent number of extracted parameters. It is shown that this model compares more favorably with the experimental data than previous models. The implicit dependencies of the model parameters on oxide charge density and surface roughness are confirmed     

Highly sensitive capacitance measurement for sensors

Very small capacitance changes from a capacitive transducer can be measured using a custom-designed signal-processing chip. The chip features a switched-capacitor integrator with chopper stabilisation to remove the effects of offset, 1/f noise and switch charge injection; the circuit is insensitive to stray capacitance. The achievement of high resolution and low drift is demonstrated.<>     

Real-time elliptical head contour detection under arbitrary pose and wide distance range

In this paper, we propose a real time elliptical head contour detection method based on quadrant arcs, which is efficient and robust to arbitrary head pose and wide distance range. First, the moving object area is detected according to background model which is built on three color channels. Then, all the valid elliptical arcs are extracted out from connected edges, and classified into four kinds of quadrant arc sets according to their gradient information. Finally, the arcs lying in different sets are combined to fit out the elliptical head contour based on the least square method. Experimental results confirm the robustness and the accuracy of this method under arbitrary head pose and wider distance range, as well as the real time property, strong robustness to long or short hair and with or without hat.