不同注F剂量与CMOS运放电路辐照损伤的相关性

在不同注F剂量条件下,对P沟和N沟两种不同差分对输入CMOS运放电路的电离辐照响应进行了研究.分析比较了注F和未注F运放电路电离辐照响应之间的差异.结果表明,在栅场介质注入适量的F,可有效抑制辐照感生的氧化物电荷尤其是界面态的增长,从而提高CMOS运放电路的抗辐照特性.     

PARASITIC TOLERANT DIFFERENTIAL SC TRANSCONDUCTANCE USING UNITY GAIN BUFFERS

The unity gain buffer will be good to design high frequency SCF if its resistiveeffects can be eliminated,and therefore the whole parasitic sensitivities will greatly be reduced.On the basis of this concept,a novel parasitic tolerant SC DTE(differential transconductanceelement)is proposed.SC floating inductor and integrator fit for high frequency applications areformed by the DTE.The computer simulation and experiment on a third order elliptic LP filterverify its validity.     

MASH ΣΔ modulators with a noise-shaped two-step ADC in the second stage

In this paper, a multi-stage noise-shaping (MASH) sigma-delta (ΣΔ) modulator is proposed to be used in low oversampling ratio (OSR) applications. It utilizes a noise-shaped two-step (NSTS) analog-to-digital converter (ADC) in the second stage and benefits its inter-stage gain to provide an extra attenuation of the quantization noise such that the same specifications of a traditional modulator are achieved but with a lower order of noise-shaping. Furthermore, large number of bits is resolved in the second stage while equal number of comparators is used. Compared to the single-loop NSTS ADC, in the proposed structure, the complexity problem of the feedback path and coefficient spreading are eliminated. As an example, a MASH 2-1 sigma-delta modulator has been designed and simulated in a 90 nm CMOS process using Spectre. The achieved resolution is 13.44 effective number of bits in 6.25 MHz signal bandwidth while consuming 19.6 mW power from a single 1 V supply. The sampling frequency is 100 MHz and the simulated figure of merit is 141 fJ/conv-step which shows the efficiency of the proposed modulator.     

一种LC-VCO 1/f3相位噪声优化方法

建立了差分互补型电感电容压控振荡器(LC-VCO)的等效分析模型.采用有效截止频率厂T.e.来表征MOS管的充放电能力,结合振荡器起振后共模输出电压下降的现象,提出了优化1/f3相位噪声的方法.采用该方法并结合跨导效率gm/ID设计方法,实现了LC-VCO 1/f3相位噪声的优化,并在0.18 μm CMOS工艺上获得验证.结果表明,该优化方法可以使频偏在1 kHz以内的相位噪声改善2～3 dB,可用于开环LC-VCO作为本振的低功耗无线收发机及高性能晶体振荡器的电路设计中.     

晶体管混频器混频增益的简化计算

本文介绍一种方法简单、便于学生理解的分析晶体管混频器混频增益的简化计算方法.该方法从晶体管的电流方程入手,通过分析晶体管混频器的混频原理,得到了输出中频电流和混频跨导、混频增益的简明数学表示.通过对典型混频器电路的仿真,验证了该方法的有效性.该方法与传统的时变偏置电压分析方法相比,混频跨导和混频增益容易求得,解决了以往混频跨导基本是一个概念参数而难以确定具体数值的问题.     

H型栅结构的亚微米PDSOI MOS器件的跨导双峰效应研究

A bimodal effect of transconductance was observed in narrow channel PDSOI sub-micron H-gate PMOSFETs,which was accompanied with the degeneration of device performance.This paper presents a study of the transconductance bimodal effect based on the manufacturing process and electrical properties of those devices.It is shown that this effect is caused by a diffusion of donor impurities from the NC region of body contact to the PC poly gate at the neck of the H-gate,which would change the work function differences of the polysilicon gate and substrate.This means that the threshold voltage of the device is different in the width direction,which means that there are parasitic transistors paralleled with the main transistor at the neck of the H-gate.The subsequent devices were fabricated with layout optimization,and it is demonstrated that the bimodal transconductance can be eliminated by mask modification with NC implantation more than 0.2 m away from a poly gate.     

基于SPM的光子探测技术

光子探测技术是弱光探测领域的热点,介绍了SPM(硅光电倍增管阵列)探测器件的工作原理、基本结构、性能特点,为了验证SPM探测器的光子探测性能以及光子分辨能力,利用高速跨导放大器设计了SPM光子探测电路,并进行了光子探测实验研究。根据实验结果可以得出结论,SPM探测器具有较好的光子分辨特性。     

改进型循环折叠共源共栅放大器的分析与实现

本文分析并实现了一种改进型循环折叠共源共栅放大器（IRFC）。本文分析了IRFC并将其与循环折叠共源共栅放大器（RFC）和传统折叠共源共栅放大器（FC）进行了比较,并证明IRFC能显著提升跨导、压摆率和噪声性能。放大器由0.13微米工艺实现,测试结果表明在相同功耗和面积的条件下,IRFC的单位增益带宽和压摆率是FC的3倍,并且是RFC的1.5倍。     

$lt;i$gt;γ$lt;/i$gt;射线总剂量辐照效应对应变Sip型金属氧化物半导体场效应晶体管阈值电压与跨导的影响研究

分析了双轴应变Si p型金属氧化物半导体场效应晶体管(PMOSFET)在γ射线辐照下载流子的微观输运过程, 揭示了γ射线的作用机理及器件电学特性随辐照总剂量的演化规律, 建立了总剂量辐照条件下的双轴应变Si PMOSFET 阈值电压与跨导等电学特性模型, 并对其进行了模拟仿真. 由仿真结果可知, 阈值电压的绝对值会随着辐照总剂量的积累而增加, 辐照总剂量较低时阈值电压的变化与总剂量基本呈线性关系, 高剂量时趋于饱和; 辐照产生的陷阱电荷增加了沟道区载流子之间的碰撞概率, 导致了沟道载流子迁移率的退化以及跨导的降低. 在此基础上, 进行实验验证, 测试结果表明实验数据与仿真结果基本相符, 为双轴应变Si PMOSFET辐照可靠性的研究和应变集成电路的应用与推广提供了理论依据和实践基础. 关键词： 应变Sip型金属氧化物半导体场效应晶体管 总剂量辐照 阈值电压 跨导     

应用于包络跟踪的高线性跨导运算放大器的设计

设计了一款改进的基于交叉耦合结构的跨导运算放大器(OTA)。设计和分析过程中依据严格的理论推导,新结构在高输入摆幅下线性度得到明显优化,当输入为2V@5MHz正弦波时,谐波总量从0.7%降至0.3%,并成功应用于包络跟踪功率放大器。仿真测试基于CSMC 0.5μm CMOS工艺,仿真结果表明二到五次谐波分量总和从传统OTA的-40 dB降低到-52 dB,同时在VSS系统联合仿真平台上,用15 MHz带宽的OFDM调制信号测试星座图,其聚敛性也得到了明显优化,矢量误差从4.7%降至3.6%。