开关电流电路基本单元误差分析及其改进

开关电流技术(SI)是一种可取代开关电容技术的数据采样技术.首先介绍了SI技术,然后以SI电路基本单元为例,分析了SI电路存在的各种误差,并针对这些误差提出了解决方法;最后提出了一种新的改进电路.实验结果表明,采用TSMC 0.35μm工艺参数和Hspice仿真电路,所设计的电路误差小,输出波形理想,从而可达到预期的目的.     

开关电流电路及其误差分析

开关电流(SI)技术是有望取代开关电容技术的一种新的采样数据技术。首先介绍了开关电流技术的概念及优点,然后以SI电路基本存储单元为例分析了开关电流电路中可能存在的误差。最后,针对电路中存在的失配误差、传输误差、噪声误差及电荷注入误差等提出了一些解决方法,如S2I技术等。     

一种多功能可调开关电流双二次滤波器的实现

采用改进的Class AB开关电流(SI)存储单元设计了差分结构双线性SI积分器,由此积分器和栅极接地Class AB电流乘法器作为基本模块,设计了SI双二次滤波器.电路实现了低通(LP)、带通(BP)和高通(HP)滤波器,其截止频率ωo和Q值可通过外部直流电流连续调节.仿真结果表明设计的电路具有良好的滤波和可调性能.     

一种新的开关电流双二次滤波器

本文阐述了开关电流(SI)和开关电容(SC)电路的相似性原理,由此提出了一个新的SI双二次滤波器电路,该电路是由文献[5]的三运放SC双二次电路为原型导出的。该电路的一个重要特征是:它在单一积木块上能同时获得低通、带通和高通滤波功能。据此,得到了SI电路的一般双二次实现。     

基于信号流图的开关电流滤波器设计

开关电流（SI）是有望取代开关电容（SC）的一种新型的取样数据技术，鉴于SC技术发展的成熟性及其与SI技术的紧密联系，即SC和SI滤波电路具有互易性，可采用信号流图转置的方法，将SC综合法直接用于SI滤波器设计，而无须提出新的设计方法。本文以二阶巴特沃思开关电容带通滤皮器为例给出了该方法的具体应用。     

小波变换开关电流电路CAD设计

用开关电流技术实现小波变换,关键是小波滤波器的实现;小波滤波器传输表达式可通过对小波基函数的有理逼近来获得。基于Padé逼近的方法,采用高斯函数族作为小波基函数,对所选的高斯函数进行频域的有理分式逼近来获取小波滤波器传输表达式,从数学上提出一种设计小波变换开关电流(SI)滤波器的CAD方法。结合SI的电流模信号特点,利用双二次滤波器的性质,用SI单元电路的级联结构来实现电路的灵活设计。设计举例给出了设计思路,MATLAB仿真结果显示这种方法的可行性。     

一种新型Class AB开关电流存储单元的设计

设计了一种新型高性能Class AB开关电流(SI)第一代存储单元电路。电路由对称的电压反转跟随器(FVF)连接Class AB SI存储单元组成,输入级采用电流传输器结构,输出级采用可调共源共栅结构,电路具有误差小、功耗低、性能高等特点。基于此存储单元,设计了延时器和双线性积分器进行验证。电路采用SMIC 0.18μm工艺,在Spectre中进行仿真。结果表明,该存储单元具有较好的性能和应用价值。     

开关电流电路故障诊断技术的初步研究

开关电流(SI)技术是模拟采样数据处理技术。介绍了开关电流电路的基本单元结构,讨论了影响故障诊断精度的主要因素,重点分析了电荷注入误差。对于开关电流电路故障诊断的仿真,介绍了一种故障模型,仿真后通过误差电流的不同来进行故障定位,但在PSpice仿真上实现还存在一定困难。     

新型多功能开关电流双二次滤波器

本文提出了一种具有较低灵敏度和正反两相输出的开关电流(SI)改进型通用积木块(MUB),可以实现抽样数据信号处理的各种基本运算.据此,以开关电容电路为原型,采用信号流图方法生成了一种新型SI高Q双二次滤波器,可获得低通、高通、带通和带阻等多种滤波功能。     

开关电流技术与过采样A／D变换器

开关电流(SI)电路技术与标准数字CMOS工艺的完全兼容使得它成为实现过采样A／D变换器乃至单片模数混合集成系统的理想选择。本文讨论了开关电流电路技术及其在过采样A／D变换器的应用，包括开关电流电路的基本单元及其各种改进型，实现过采样A／D变换器中调制器的建构模块和制器的结构。     

SWITCHED-CURRENT FILTER DESIGN USING CASCADED SECTIONS

A new analogue sampled-data active device, named as a switched-current operationalamplifier (SIOA), is presented. The use of active circuit elements may simplify drawing the circuitdiagram significantly greatly and may permit easier analysis and synthesis of SI networks. Anumber of all pole and elliptic (second-or third-order) switched-current (SI) filters are derivedfrom the switched capacitor prototypes. These can be used as simple self-contained filters or asfilter sections in the cascaded realizations of a higher order transfer functions. To illustrate theapproach, a fifth-order low-pass filter is designed.     

多功能开关电流双二次滤波器生成

本文提出了一个具有差分输出的通用开关电流一阶积木块，并阐述了采用该积木块生成多功能ＳＩ滤波器的系统方法，以单放大器，两放大器和三放大器有源ＲＣ或ＳＣ网络为原型，系统地导出了一系列新的ＳＩ双二次结构，生成的所有ＳＩ电路均可在单一积木块上同时获得低通、高通和带通滤波功能，这些电路的灵敏度低，且为纯ＭＯＣ管结构，非常适合于数字ＣＭＯＳ工艺集成。     

Accurate SI filters using RGC integrators

The design and implementation of single-ended and fully-differential switched current (SI) biquadratic high-Q bandpass filters to meet the specifications of the dual-tone multiple-frequency (DTMF) system are presented. Both designs use the regulated-gate cascode (RGC) dynamic current mirror to obtain center frequency accuracy of 0.1% and a quality factor of 24. Compared to the equivalent switched capacitor (SC) implementation of these filters, the single-ended SI filter requires 30% less area for the same minimum-sized capacitance, power dissipation and performance     

A new switched current circuit fault diagnosis approach based on pseudorandom test and preprocess by using entropy and Haar wavelet transform

This paper presents a new switched current (SI) circuit fault diagnosis approach based on pseudorandom test and preprocess by using entropy and Haar wavelet transform. The proposed method has the capability to detect and identify faulty transistors in SI circuit by analyzing its time response. The use of pseudorandom sequences as a stimulate signal to SI circuit reduces the cost of testing and the overhead of the test generation circuit, and using entropy and Haar wavelet transform to preprocess the time response for feature extraction drastically improves the fault diagnosis efficiency. For both actual experiment and analysis of switched current filters in Z transform (ASIZ) simulation, a low-pass, a band-pass SI filter and a clock feed-through cancellation circuit have been used as test examples to verify the effectiveness of the proposed method. The result shows that the accuracy of fault recognition achieved is about 100% by analyzing low-frequency approximations entropy and high-frequency details entropy. Therefore, it indicates that the presented method is superior than other methods.     

任意阶开关电流低通滤波器的系统设计

提出了任意阶开关电流低通滤波器的一种系统设计方法,该方法遵循从RLC滤波器到有源RC滤波器,再到开关电容滤波器,最后到开关电流滤波器的顺序进行设计,方法简单易行.给出了3阶开关电流低通滤波器的设计实例,ASIZ仿真频率响应满足所需要的频率技术要求.     

On the Evaluation of the Exact Output of a Switched Continuous-Time Filter and Applications

In this paper, a study of the operation of switched continuous-time filters (SCTFs), defined as continuous-time filters with elements that are alternatively switched on and off in the signal path, is conducted. A well-known example is the use of switched resistors to multiply their value, but the universe of applications is wider. First, a detailed calculation of the output of an SCTF in the frequency domain, which allows the examination of any SCTF in a general framework, is presented. This result particularly explains the resistor multiplication effect. Three application examples using switched elements are presented and examined as SCTFs: a nonideal sample & hold, a switched active filter that is tuned by varying the duty cycle of the switching, and a switched $G_m$–$C$ filter to implement a chopper amplifier. In all cases, the theoretical background allows the examination of circuit behavior and limitations, and the analysis is supported by measurements or transient simulations.      

离散Hopfield神经网络和联想记忆的开关电流技术实现

研究了离散Ｈｏｐｆｉｅｌｄ神经网络（ＤＨＮＮ）和联想记忆神经网络的开关电流技术实现，利用多权输入跨导，开关电流延迟器（ＳＩＤ）和可编程电流比较器（ＰＣＣ）实现了离散Ｈｏｐｉｅｌｄ神经网络，并提出了利用离散Ｈｏｐｆｉｅｌｄ神经网络实现自联想记忆时相应的开关电流电路，所提出了开关电流神经网络适宜于超大规模集成，能在低电压（如３．３Ｖ）下工作。     

A new swarm-SVM-based fault diagnosis approach for switched current circuit by using kurtosis and entropy as a preprocessor

This paper presents a new fault diagnosis method for switched current (SI) circuits. The kurtoses and entropies of the signals are calculated by extracting the original signals from the output terminals of the circuit. Support vector machine (SVM) is introduced for fault diagnosis using the entropies and kurtoses as inputs. In this technique, a particle swarm optimization is proposed to optimize the SVM to diagnose switched current circuits. The proposed method can identify faulty components in switched current circuit. A low-pass SI filter circuit has been used as test beached to verify the effectiveness of the proposed method. The accuracy of fault recognition achieved is about 97 % although there are some overlapping data when tolerance is considered. A comparison of our work with Long et al. (Analog Integr Circuit Signal Process 66:93–102, 2011), which only used entropy as a preprocessor, reveals that our method performs well in the part of fault diagnostic accuracy.     

Architecture for low-voltage switched-current complex bandpassfilters

An architecture for the switched-current (SI) realisation of complex filters is presented, based upon the signal flow-graph method. Also briefly discussed is a practical design flow for SI complex filters, based on that for traditional real SI filter designs. A verification of the architecture is given via the design and simulation of a fifth-order complex SI bandpass filter with 1 MHz centre frequency and bandwidth, implemented using a low-voltage class AB neutralised SI scheme