New sinusoidal oscillator configurations using operational transresistance amplifier

The objective of this brief is to introduce four new structures of electronically tunable sinusoidal oscillators (SOs) designed using operational transresistance amplifier (OTRA). Each of the proposed SO consists of forward path derived from a generic structure along with one/two OTRA-based resistive gain stages or differentiator in its feedback path. All the proposed SOs enjoy independent tuning of the frequency of oscillation (FO) through resistors without affecting the condition of oscillation (CO). Further, all topologies are found to exhibit low f_o sensitivities at all frequencies with respect to circuit parameters, and the second topology is capable of achieving very low frequencies (VLFs) using less RC component spread and provides linear tuning too. The fourth circuit provides quadrature output. The proposed SOs have been successfully implemented and verified in 180-nm CMOS technology node using ADE (analog design environment) tool Cadence Virtuoso. Both prelayout and postlayout simulation results have been included. To assess the oscillator prefabrication performances, Monte Carlo and process-voltage-temperature (PVT) analyses have been performed. The total harmonic distortion (THD) is observed to be less than 3.5%.     

基于OTRA的通用双二阶滤波器设计

提出了把通用双二阶滤波器视为负反馈放大器的观点,根据反馈电路的基本方程,利用3个MOS电阻、2个电容、2个运算跨阻放大器(OTRA)构成了通用双二阶滤波器,该滤波器不仅可从同一端口输出信号,从不同端口输入信号,而且可获得低通、高通、带通、带阻和全通输出.该电路结构简单,便于电控调谐.     

Novel grounded inductance simulator using single OTRA

In this paper, a method to realize a grounded inductor using single operational transresistance amplifier is presented. The simulated inductance value can be controlled independent of realizability condition. The non‐ideality analysis of the circuit is also given. The workability of the proposed simulated inductance is demonstrated through two applications namely, a band pass filter and an oscillator. PSPICE simulation and experimental results agree well with the theoretical values. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis of active inductors using SFG stamps

This paper proposes a new approach for the systematic synthesis of active inductors via signal-flow graphs (SFGs). The basic idea consists of proposing and using SFG stamps of active basic building blocks (ABBs) to construct the equivalent SFG of a classical inductor. We show that a large number of active inductors can be thus synthesized; twelve are proposed, most of them are novel. Known ABBs, as well as newly proposed ones are used, namely current conveyors (CC), operational transconductance amplifiers (OTA), current conveyor transconductance amplifiers (CCII-TA), current feedback operational amplifiers (CFOA), operational transresistance amplifiers (OTRA), current backward transconductance amplifiers (CBTA), current feedback transconductance amplifiers (CFTA) and voltage differencing inverting buffered amplifiers (VDIBA). SPICE simulations are given to show the viability of the proposed technique.     

基于OTRA电流模式二阶通用滤波器的设计

鉴于单个OTRA电流模式滤波器未见报道,以CCⅡ二阶通用电流模式滤波器为原型,利用1个OTRA,1个MOS电压跟随器,1个CMOS电压反相器,3个电阻和2个电容,构成了二阶通用电流模式滤波器,可同时获得高通、带通和低通输出。与传统电路相比,该电路能减小寄生电容的影响,因而有较高的稳定性;调节极点角频率与品质因素的元素多,因而调整方便,且通带增益可调范围广,无源灵敏度较低,电路结构简单,便于电控调谐,特别适合单片集成技术。