低功耗、全差分流水线操作CMOSA/D转换器

提出一种基于运算跨导放大器共享技术的流水线操作A/ D转换器体系结构,其优点是可以大幅度降低芯片的功耗和面积.采用这种结构设计了一个10位2 0 MS/ s转换速率的全差分流水线操作A/ D转换器,并用CSMC0 .6 μm工艺实现.测试结果表明,积分非线性为1.95 L SB,微分非线性为1.75 L SB;在6 MHz/ s采样频率下,对1.84 MHz信号转换的无杂散动态范围为5 5 .8d B;在5 V工作电压、2 0 MHz/ s采样频率下,功耗为6 5 m W.     

14位50MS/s100mW0.18μm CMOS流水线ADC

实现了一种14位40MS/s CMOS流水线A/D转换器(ADC)。在1.8V电源电压下,该ADC功耗仅为100mW。基于无采样/保持放大器前端电路和双转换MDAC技术,实现了低功耗设计,其中,无采样/保持放大器前端电路能降低约50%的功耗,双转换MDAC能降低约10%的功耗。该ADC采用0.18μm CMOS工艺制作,芯片尺寸为2.5mm×1.1mm。在40MS/s采样速率、10MHz模拟输入信号下进行测试,电源电压为1.8V,DNL在±0.8LSB以内,INL在±3.5LSB以内,SNR为73.5dB,SINAD为73.3dB,SFDR为89.5dBc,ENOB为11.9位,THD为-90.9dBc。该ADC能够有效降低SOC系统、无线通信系统及数字化雷达的功耗。     

一个59mW 10位40MHz流水线A/D转换器

设计了一个工作在3.0V的10位40MHz流水线A/D转换器,采用了时分复用运算放大器,低功耗的增益自举telescopic运放,低功耗动态比较器,器件尺寸逐级减小优化功耗.在40MHz的采样时钟,0.5MHz的输入信号的情况下测试,可获得8.1位有效精度,最大积分非线性为2.2LSB,最大微分非线性为0.85LSB,电路用0.25μm CMOS工艺实现,面积为1.24mm2,功耗仅为59mW,其中同时包括为A/D转换器提供基准电压和电流的一个带隙基准源和缓冲电路.     

一个59mW 10位40MHz流水线A/D转换器

设计了一个工作在3.0V的10位40MHz流水线A/D转换器,采用了时分复用运算放大器,低功耗的增益自举telescopic运放,低功耗动态比较器,器件尺寸逐级减小优化功耗.在40MHz的采样时钟,0.5MHz的输入信号的情况下测试,可获得8.1位有效精度,最大积分非线性为2.2LSB,最大微分非线性为0.85LSB,电路用0.25μm CMOS工艺实现,面积为1.24mm2,功耗仅为59mW,其中同时包括为A/D转换器提供基准电压和电流的一个带隙基准源和缓冲电路.     

一种1.5 V 8位100 MS/s电流舵D/A转换器

基于新型的低压与温度成正比(PTAT)基准源和PMOS衬底驱动低压运算放大器技术,采用分段温度计译码结构设计了一种1.5V8位100MS/s电流舵D/A转换器,工艺为TSMC0.25μm2P5MCMOS。当采样频率为100MHz,输出频率为20MHz时,SFDR为69.5dB,D/A转换器的微分非线性误差(DNL)和积分非线性误差(INL)的典型值分别为0.32LSB和0.52LSB。整个D/A转换器的版图面积为0.75mm×0.85mm,非常适合SOC的嵌入式应用。     

基于混合结构的一种高性能90nm CMOS逐次逼近A/D转换器

实现了一种10位2.5MS/s逐次逼近A/D转换器。在电路设计上采用了R-C混合结构D/A转换、伪差分比较结构以及低功耗电平转换方式实现。为了实现好的匹配性能,在版图布局上分别采用电阻梯伪电阻包围对策以及电容阵列共中心对称布局方式进行布局。整个A/D转换器基于90nm CMOS工艺实现,在3.3V模拟电源电压以及1.0V数字电源电压下,测得的DNL和INL分别为0.36LSB和0.69LSB。在采样频率为2.5MS/s,输入频率为1.2MHz时,测得的SFDR和ENOB分别为72.86dB和9.43bits。包括输出驱动在内,测得整个转换器的功耗为6.62mW。整个转换器的面积约为238um×214um。设计结果显示该转换器性能良好,非常适合多电源嵌入式SoC的应用。     

一种10位100-MS/s CMOS流水折叠式A/D转换器

采用流水折叠结构设计了一种10位100-MSample/s A/D转换器。失调取消技术和电阻平均插值网络提高了转换器的线性度。级联结构放宽了折叠放大器的带宽要求,采用分布式级间跟踪保持放大器实现流水线技术来获得更高的转换精度。基于SMIC 0.18 μm CMOS工艺的测试结果如下：INL和DNL的峰值分别为0.48 LSB and 0.33 LSB。输入电压范围VP-P为1.0 V,芯片面积2.29 mm2。100 MHz采样,20 MHz输入信号下,ENOB为9.59位,SNDR为59.5 dB,SFDR为82.49 dB。1.8V电源电压下功耗仅为95 mW。     

0.18 μm 1.8 V 10 bit 100 MS/s CMOS电流舵D/A IP设计与验证

基于GSMC 0.18μm CMOS工艺,采用曲率补偿带隙参考电压源和中心对称Q2随机游动对策拓扑方式的NMOS电流源阵列版图布局,实现了一种10 bit 100 MS/s分段温度计译码CMOS电流舵D/A转换器.当电源电压为1.8 V时,D/A转换器的功耗为10 mW,微分非线性误差和积分非线性误差分别为1 LSB和0.5 LSB.在取样速率为100 MS/s,输出频率为5 MHz条件下,SFDR为70 dB,10 bit D/A转换器的有效版图面积为0.2 mm2,符合SOC的嵌入式设计要求.     

低功耗10位30MS/s流水线A/D转换器

基于0.18μm CMOS混合信号工艺,设计了一个低功耗10位30 MS/s流水线A/D转换器.通过优化各级采样电容和运放(0TA)偏置电流,以及使用动态比较器,大大降低了整体功耗.采用增益自举开关,以减少开关非线性;引入数字校正技术,以提高转换精度.当采样时钟频率为32 MHz、输入信号频率为16 MHz时,信噪失真比(SNDR)为59 Db,无杂散动态范围(SFDR)为71 Db.AD(:核心电路版图面积为0.64 mm2,功耗仅为32 Mw.     

一种57.6mW,10位,50MS/s流水线操作CMOS A/D转换器

在1.8V,0.18μm CMOS工艺下,实现了10位,50MS/s流水线操作A/D转换器的设计和测试.通过优化采样电容和运算跨导放大器(OTA)电流,并采用动态比较器,从而降低功耗;采用复位结构的采样/保持和余量增益电路消除OTA失调电压的影响;优化OTA的次极点,保证其工作稳定.测试结果表明:ADC在整个量化范围内无失码,功耗为57.6mW,失调电压为0.8mV,微分非线性为-0.6～0.7LSB.对5.1MHz的输入信号量化,可获得44.9dB的信号与噪声及谐波失真比.电路面积为0.52mm2.     

一款切合实际的30A能量计

本文介绍了一款集成了30A检测电阻器LTC2947.     

注钼纯铝的研究

利用从金属蒸汽真空弧离子源（简称ＭＢＶＶＡ源）引出的强束流钼离子对纯铝进行了不同束流密度的离子注入。加速电压为４８ｋＶ，剂量为３×１０￣（１７）ｃｍ￣（－２），束流密度为２５和４７μＡ·ｃｍ￣（－２），Ｘ衍射分析证明在注入层内可形成Ａｌ＿（１２）Ｍｏ晶体，背散射（ＲＢＳ）分析证明Ａｌ＿（１２）Ｍｏ的厚度可达６００至７００ｎｍ。     

高速高精度A/D转换器

本文介绍了用于观测太阳磁场的天文望远镜系统的高速高精度局部级联式多阈值A/D转换器。文章着重讨论了,为实现高速、高精度所采用的技术要点,并提出了研制高速高精度A/D转换器所必须考虑的有关问题。 我们所研制的A/D转换器,分辨率为1mV,相对误差0.025％,字长12位,前面接采样保持电路后,速度为10万次/秒。     

A charge-balancing monolithic A/D converter

The quest for a minimum-parts-count DPM led to the development of this monolithic, low power analog-to-digital converter. It incorporates the analog and digital functions historically implemented separately with specialized process technologies into a chip with full /spl plusmn/3 digit accuracy. The integration of resistors, compensation capacitors, and an oscillator reduces the external component complement to three capacitors and one adjustable reference. TTL compatible outputs include sign, overrange, and under range information in addition to the three digit strobes and the BCD data outputs. The logic operates between +5 V and ground, the linear section between +5 V and -5 V. The paper describes the conversion algorithm and its CMOS implementation, emphasizing the analog design of this innovative device.     

A Convenient Multivariate Gram-Charlier Type A Series

It is often necessary to approximate the probability density function of a random variable from given statistical moments. The Gram-Charlier Type A series is one well known method for such representations. In this note, the Gram-Charlier Type A series is generalized to the multidimensional case.     

一种识别说话者的新方法

在能够自动识别视频中的说话者的系统中,大部分采用的是声音和唇部运动相结合的方法。文中则采用了另一种方法有效地达到了目的,即通过检测人体头部和手部的运动来鉴别说话者。基于演讲者在说话时通常会伴有头部运动或是手部运动,该方法既能实现说话者的检测,又能避免由于观测点过远而导致无法判断人唇部运动的局限性。在系统的实施过程中,运用了多种图像处理方法,并且对三帧差运动法做出了改善,使其能更高效、更准确地检测到头部和手部的运动。经过多个不同的视频测试后,本系统的F1 score高达91．91％,从而验证了该系统的可行性。     

A Nyquist-rate delta-sigma A/D converter

This paper describes an analog-to-digital converter which combines multiple delta-sigma modulators in parallel so that time oversampling may be reduced or even eliminated. By doubling the number of Lth-order delta-sigma modulators, the resolution of this architecture is increased by approximately L bits. Thus, the resolution obtained by combining M delta-sigma modulators in parallel with no oversampling is similar to operating the same modulator with an oversampling rate of M. A parallel delta-sigma A/D converter implementation composed of two, four, and eight second-order delta-sigma modulators is described that does not require oversampling. Using this prototype, the design issues of the parallel delta-sigma A/D converter are explored and the theoretical performance with no oversampling and with low oversampling is verified. This architecture shows promise for obtaining high speed and resolution conversion since it retains much of the insensitivity to nonideal circuit behavior characteristic of the individual delta-sigma modulators     

A charge-domain D/A conversion system

In this article, a new multiplication type D/A conversion system using CCD is proposed and the result of simulations for evaluating its performance is reported. The system consists of a recursive charge divider which divides input charge-packet Qin sequentially into output charge-packets Qin · 2^-i and two charge-packet accumulators which accumulates output charge-packets from the recursive divider selectively according to digital input signal bits starting from MSB. The system converts input digital signal bit by bit, fully in charge-domain, thus the power consumption for this system is supposed to be very low. Also in this article, an effective method to achieve higher accuracy for splitting a charge-packet into two equal-sized packets using very simple hard-ware structure is proposed. As the result of simulations, we have found that the upper limit of accuracy for the conversion is determined by transfer efficiency of CCD, and within this range a trade-off relationship exists among conversion-accuracy, circuit-size and conversion-rate. This unique relationship enables to reduce the circuit size of D/A converter significantly maintaining the accuracy of conversion by slowing down the conversion-rate. This D/A converter is appropriate especially for the system integration because of its simple structure, tolerance to the fabrication error and low power consumption inherrent in the nature of CCD. By using of this system, it is expected to be possible to realize a focal plane image processor performing parallel analog operations such as DCT conversion with CCD imager incorporated on the same Si chip by the same MOS process technology.     

A monolithic video A/D converter

The design and measured performance of a fully parallel monolithic 8-bit A/D converter is reported. The required comparators and combining logic were designed and fabricated with a standard high-performance triple-diffused technology. A bipolar comparator circuit giving good performance with high input impedance is described. Circuit operation is reported at sample rates up to 30 megasamples per second (MS/s), with analog input signal power at frequencies up to 6 MHz. Full 8-bit linearity was achieved. An SNR of 42-44 dB was observed at input signal frequencies up to 5.3 MHz.     

没有管理者的密钥共享方案

一般的密钥共享方案中都假设有一个管理者,管理者的作用是分发密钥,因此对管理者的可信要求很高,而现实生活中很难找到符合要求的管理者.文中利用单调存取结构上的张成方案构造了一个没有管理者的密钥共享方案,并证明其是一个可行的实用的密钥共享方案.基于这个的方案,构造了一个分布式密钥生成器.