新器件简讯(10)

<正> 单线数字温度传感器DS1820 一般的温度传感器输出与温度成比例的电压信号或电流信号,它们都是模拟信号。因此用于微处理器进行温度测量或控制时,需要将温度传感器输出的模拟信号经A/D变换器转变成数字信号。 DS1820单线数字温度传感器可以直接感受温度并输出数字信号,与微处理器直接接口,这样系统简化,提高可靠性。 DS1820单线数字温度传感器的测量温度为-55℃～+125℃,增量为0.5℃,相应输出9位数字信号,如下表所     

支路阻抗变化引起电流变化的等效分析

本文证明了一个适用于线性含独立源网络的结论：当某支路阻抗变化之前，该支路的电流已知或容易求出时，在这个阻抗变化后能够很容易地求出该支路的电流增量或者电压增量，以及其它支路的电流增量或电压增量。利用此结论可以进一步求出对应支路新的响应或进行灵敏度分析。本文给出了一些实例并讨论了这个结论的应用。     

LM135系列精密温度传感器的原理和应用

一、概述 LM135系列温度传感器是一种电压输出型精密集成温度传感器。它工作类似于齐纳二极管,其反向击穿电压随绝对温度以+10 mV/K的比例变化,工作电流为 0.4—5 mA,动态阻抗仅为10,便于和测量仪表配接。这种温度传感器具有测量精度高,应用简单等优点。LM135系列温度传感器的测温范围很宽,LM135测温范围为-55-+150℃,LM235和LM335测温范围分别为-40-+125℃和     

数字式SWC温度传感器

由广州54060部队研制成功的数字式 SWC 温度传感器是一种设计新颖,计量准确,基本不受传输距离限制的传感器。目前国内外温度传感器一般是把温度信号转换为模拟电压或电流信号输出,该传感器则直接将被测信号转换为已标定的数字信号输     

确实适合各种应用的模拟和数字温度传感器

ADI公司能够提供适应任何应用的模拟和数字温度传感器。对于只需要基本功能的应用，例如简单的电压或者电流输出，ADI公司提供一系列模拟温度传感器。这些模拟传感器无需微调、缓冲和线性化，从而节省了成本和不必要的电路设计。     

电子学中重要的测量仪器-电子示波器的简介

电子示波器是一种能把随时间变化的电信号用图象显示出来的电子仪器。用它来观察电压或电流（被转化成电压的电流）的波形,并可测量出电压的幅度、频率和相位等。因它可以把电压或电流的变化用时间函数的形式描绘显示在荧光屏上,因此示波器是时域测量中一种用来分析电信号的重要显示仪器。示波器被广泛地应用在无线电测量中。     

集成温度传感器AD590及其应用

<正> 集成温度传感器实质上是一种半导体集成电路,它是利用晶体管的 b-e 结压降的不饱和值 VBE 与热力学温度 T 和通过发射极电流 I 的关系实现对温度的检测。集成温度传感器具有线性好、精度适中、灵敏度高、体积小、使用方便等优点,得到广泛应用。集成温度传感器的输出形式分为电压输出和电流输出两种。电压输出型的灵敏度一般为10mV/K,温度0℃时输出为0,温度25℃时输出2.982V。电流输出型的灵敏度一般为1μA/K。     

功率电子管帘栅极的稳定供电

在电子管功率放大器中．当工作信号为峰值时．输出功率管的屏极电流和帘栅极电流都将增大，这会引起相应电路的供电电压下降，其中帘栅极电流的变化又远大于屏极电流的变化。帘栅极电压的降低对五极或集射功率电子管的工作影响很大，     

HEV动力电池组数据采集系统设计

数据采集电路主要完成电池组总电压、各单体电池电压、充放电电流、电池表面温度等信号的实时采集.电池组电压检测主要通过精密电阻进行分压处理;电流检测是通过霍尔电流传感器LTS6-NP将电流信号转换成电压信号;温度检测主要采用LM35温度传感器将温度信号转换成电压信号.将此采集方案和卡尔曼滤波修正算法结合计算得到的SOC值平...     

无需单独供电的远程温度传感器

在远程位置上测试温度是一种很普遍的需求,但要实现起来,并非那么简单。大多数温度传感器有一个电压或电流输出,为使噪声检取降为最低,应该在靠近传感器就     

A Temperature Sensor With an Inaccuracy of ${-}{hbox{1}}/{+}{hbox{0.8}} ^{circ}$ C Using 90-nm 1-V CMOS for Online Thermal Monitoring of VLSI Circuits

This paper proposes an accurate four-transistor temperature sensor designed, and developed, for thermal testing and monitoring circuits in deep submicron technologies. A previous three-transistor temperature sensor, which utilizes the temperature characteristic of the threshold voltage, shows highly linear characteristics at a power supply voltage of 1.8 V or more; however, the supply voltage is reduced to 1 V in a 90-nm CMOS process. Since the temperature coefficient of the operating point's current at a 1-V supply voltage is steeper than the coefficient at a 1.8-V supply voltage, the operating point's current at high temperature becomes quite small and the output voltage goes into the subthreshold region or the cutoff region. Therefore, the operating condition of the conventional temperature sensor cannot be satisfied at 1-V supply and this causes degradation of linearity. To improve linearity at a 1-V supply voltage, one transistor is added to the conventional sensor. This additional transistor, which works in the saturation region, changes the temperature coefficient gradient of the operating point's current and moves the operating points at each temperature to appropriate positions within the targeted temperature range.      

电涡流传感器热稳定性标定技术

介绍电涡流传感器位移测量原理,分析温度变化时传感器线圈和探头热胀冷缩在测量位移过程中造成的温度漂移现象.针对传感器的温漂,研制出具有温度补偿功能的电涡流传感器热稳定性标定装置,对传感器输出电压进行温度补偿,减小温度变化对传感器输出电压的影响.同时介绍利用该装置进行温度标定的实现方法,并进行实验验证,实现固定位移条件下环境温度变化时对电涡流传感器输出电压的标定,与无温度补偿时输出电压对比,电压变化量减小了近50%.     

基于Pt100铂热电阻的温度变送器设计与实现

针对空压机专用变频器系统中温度检测的要求,设计并实现了一种三线制Pt100温度传感器。利用Pt100铂热电阻的电阻-温度函数关系,将温度信号转换为电压信号,经过两级放大电路对电压信号进行放大,再将电压信号转换为标准的电流信号输出。在A／D温度采集时,利用精密电流电压转换芯片,将电流信号转换为标准的电压信号。实践证明,该传感器有较高的稳定性和灵活性,性能良好且容易实现,成本低,值得推广应用。     

Circuit-internal signal measurements with a needle sensor

We present AC current contrast and voltage contrast measurements with a needle sensor based Scanning Force Microscope. For current measurements a spatial resolution of 600 nm and a sensitivity of 100 μA are achieved while in the case of voltage measurements we demonstrate a spatial resolution of 300 nm and a sensitivity of 500 μV. A first application of current measurements with such a system in a commercial IC is shown, which could not be done with cantilever based test systems.     

气敏传感器信号采集的研究

介绍了利用计算机与单片机的串口通信采集气敏传感器的信号、控制气敏传感器电路的取样电阻和测试电压等,使气敏传感器的测量由手控转变为自动化,且其精度远远提高。文中提出使用TC232CPE芯片连接计算机与单片机,并利用气敏传感器、ADC1678芯片、AD7502芯片等建立基于RS232的计算机测量系统,此外还利用Delphi开发对采集电路的控制程序。     

GaN基蓝光micro-LED的结温和载流子温度研究

结温及载流子温度因作为影响LED发光效率的重要参数而广受关注。文章研究了GaN基蓝光集成传感微小尺寸发光二极管(micro-LED)的光致发光(PL)光谱、载流子温度等随结温的变化规律。通过内置集成传感单元芯片,设计实现了GaN基蓝光micro-LED在0.04～53.4 A/cm²电流密度下结温和PL光谱的实时精确测量,并将正向电压法测量结温的低温端范围拓展至123 K。结果表明,低温下由于载流子泄漏、串联电阻的原因,结温与正向电压的线性斜率发生变化。针对PL光谱使用高能侧斜率法计算得到不同电流密度下的载流子温度,发现载流子温度与结温在所研究的结温和电流密度范围内可以近似用二次方程拟合,并对载流子温度随结温和电流密度变化的规律进行了分析和解释。     

High sensitive and wide detecting range MOS tunneling temperature sensors for on-chip temperature detection

This paper examined the feasibility of applying a highly sensitive metal-oxide-semiconductor (MOS) tunneling temperature sensor, which was compatible with current CMOS technology. As the sensor was biased positively at a constant voltage, the gate current increased more than 500 times when the sensor was heated from 20/spl deg/C to 110/spl deg/C. However, when the sensor was biased at a constant-current situation, its gate voltage magnitude changed significantly with substrate temperature, with a sensitivity exceeding -2 V//spl deg/C. The improvement of temperature sensitivity in this paper is one thousand times over the sensitivity of a conventional p-n junction, i.e., namely, about -2 mV//spl deg/C. Regarding a temperature sensor array, this paper proposes a method using gate current gain, rather than absolute gate current, to eliminate the gate current discrepancy among sensors. For constant current operation, a sensitivity exceeding 10 V//spl deg/C can be obtained if the current level is suitable. Finally, this paper demonstrates a real temperature distribution for on-chip detection. With such a high temperature-sensitive sensor, accurate temperature detection can be incorporated into common CMOS circuits.     

Low-voltage temperature sensor for micro-power harvesters in silicon-on-sapphire CMOS

A low-voltage temperature sensor designed for MEMS power harvesting systems is fabricated. The core of the sensor is a bandgap voltage reference circuit operating with a supply voltage in the range 1-1.5 V. The prototype was fabricated on a conventional 0.5 /spl mu/m silicon-on-sapphire (SOS) process. The sensor design consumes 15 /spl mu/A of current at 1 V. The internal reference voltage is 550 mV. The temperature sensor has a digital square wave output the frequency of which is proportional to temperature. A linear model of the dependency of output frequency with temperature has a conversion factor of 1.6 kHz//spl deg/C. The output is also independent of supply voltage in the range 1-1.5 V. Measured results and targeted applications for the proposed circuit are reported.     

探针式智能温度控制仪

探针式智能温度控制仪以热敏电阻作为温度传感器,以耐高温防腐蚀的材料做外壳,能够自由伸缩50cmo以两端通入1mA恒流源的热敏电阻作为温度传感器,单片机将采得的电压信号值经过模拟放大、A／D转换器转换．LED数码管显示温度值。该温度控制仪通过串口将采样值通过高级语言显示在计算机窗口,方便直观显示存储温度值。