A single MO-CFTA based electronically/temperature insensitive current-mode half-wave and full-wave rectifiers

The article presents a current-mode full-wave rectifier employing multiple output current follower transconductance amplifier (MO-CFTA). The both circuits description is very simple, it merely comprises only single MO-CFTA, without external passive element. In addition, the magnitude and direction of output currents can be controlled via electronically method. Furthermore, the outputs are independent of the thermal voltage (VT). The performances of the proposed circuits are investigated through PSpice. They show that the proposed circuits can function as a current-mode precision half-wave and full-wave rectifiers where input current range from 0uA to 514uA and -518uA to 518uA, respectively. They can be achieved at ±2V power supplies. The maximum power consumption is 3,01mW

Current and Voltage Conveyors in Current- and Voltage-Mode Precision Full-Wave Rectifiers

In this paper new versatile precision full-wave rectifiers using current and/or voltage conveyors as active elements and two diodes are presented. The performance of these circuit solutions is analysed and compared to the opamp based precision rectifier. To analyze the behavior of the functional blocks, the frequency dependent RMS error and DC transient value are evaluated for different values of input voltage amplitudes. Furthermore, experimental results are given that show the feasibilities of the conveyor based rectifiers superior to the corresponding operational amplifier based topology

Minimum component high frequency current mode rectifier

In this paper a current mode full wave rectifier circuit is proposed. The current mode rectifiercircuit is implemented utilizing a floating current source (FCS) as an active element. Theminimum component full wave rectifier utilizes only a single floating current source, twodiodes and two grounded resistors. The extremely simple implementation enjoys highfrequency operation and provides both inverting and non-inverting rectified outputssimultaneously. The rectifier system can work up to a frequency of 500MHz with acceptabledistortion. The circuit exhibits low power consumption at ±0.75V supply voltage. Thenon-ideal and temperature analysis was also performed to study their impact on itsperformance. It was also shown that FCS can work as half wave rectifier as well. Theperformance of the circuit is evaluated using 0.18μm TSMC CMOS parameters using Hspice.Keywords: current-mode circuits; floating current source; high frequency; rectifier

Current-Mode Dual-Phase Precision Full-Wave Rectifier Using Current-Mode Two-Cell Winner-Takes-All (WTA) Circuit

In addition to the recently proposed full-wave rectifier by Prommee et al. using voltage-mode (VM)two-cell winner-takes-all (WTA) circuit, we present current-mode (CM) precision full-wave rectifier using CM two-cell WTA circuit. The popular Lazzaro’s CM WTA circuit has been employed for the purpose and there is no requirement of inverting the input signal. Also, dual complimentary phases of the output current signal are available from high-output impedance terminals for explicit utilization. As compared to many recently proposed CM rectifiers using complex active devices, e.g. dual-X current conveyor or universal voltage conveyor, our circuit is very compact and requires a total of 21 transistors. SPICE simulation results of the circuit implemented using 0.35 um TSMC CMOS technology are provided which verify the workability of the proposed circuit

A Novel Current-Mode Full-Wave Rectifier Based on One CDTA and Two Diodes

Precision rectifiers are important building blocks for analog signal processing. The traditional approach based on diodes and operational amplifiers (OpAmps) exhibits undesirable effects caused by limited OpAmp slew rate and diode commutations. In the paper, a full-wave rectifier based on one CDTA and two Schottky diodes is presented. The PSpice simulation results are included

Nonlinear Circuits with Current Operational Amplifiers

Tato diplomová práce je zaměřená na náhradu klasických napěťových operačních zesilovačů (VFOA) za proudové operační zesilovače (COA), proudové konvejory a proudové sledovače (CF). V úvodu je uvedeno pár slov o operačních zesilovačích a jejich základní zapojení, jako invertující a neinvertující zesilovač a jsou zde popsány vzorce pro výpočet zesílení. V další kapitole je popsán COA, jeho parametry a výhody oproti VFOA. Dále jsou zde popsána základní zapojení proudových konvejorů. Následuje kapitola, ve které je popsána náhrada VFOA za COA a převod mezi nimi. V další části se nejprve zabývám modely COA a CF v simulačním programu a poté náhradou VFOA za COA. Je zde popsáno několik jednoduchých zapojení, jako jsou usměrňovače, okrajovače a funkční měniče a jejich simulace před a po nahrazení VFOA za COA. U dvoucestného usměrňovače s proudovými konvejory je provedena podrobná simulace při různých vstupních napětích a frekvencích. V poslední kapitole je detailně popsán multimódový usměrňovač s proudových sledovačem. Je zde uvedena tabulka, která popisuje jednotlivé módy usměrňovače, jako je napěťový mód, proudový mód a smíšený mód a to jako jednocestný nebo dvoucestný usměrňovač. U všech těchto režimů jsou provedeny simulace. Hlavně jsou provedeny detailní simulace u napěťového a proudového módu. V další části této kapitoly je provedeno měření reálného obvodu v napěťovém a proudovém módu, při kterých byla zkoumána funkce jako jednocestného i dvoucestného usměrňovače. Z naměřených hodnot a průběhů napětí a proudů jsou uvedeny parametry usměrňovače. Nakonec jsou tyto hodnoty porovnány s hodnotami získanými pomocí simulací.This master’s thesis is about replace voltage feedback operation amplifiers (VFOA) by current operational amplifiers (COA), current conveyors and current followers (CF). In introduction are mentioned word or two about operational amplifiers and their basic circuit such as invert and non-invert amplifier and there are described formulas for calculation gain. In another chapter is described COA, his properties and advantages compared to VFOA. Next there are described basic circuits of current conveyors. Follows chapter where is described replace VFOA by COA and conversion between them. In another part is at first deal with models of COA and CF in simulating program and then replace VFOA by COA. There are some simple circuits for example precision rectifiers and function generators and their simulations before and after replace VFOA by COA. In full-wave rectifier with current conveyors is made detailed simulation with some input voltages and frequencies. In last chapter is detailed described multi-mode rectifier with current follower. There is table witch described all modes of rectifier. For example voltage mode, current mode and mixed mode with half- or full-wave rectifier. There are simulations for all modes. Primarily are made detailed simulations voltage and current mode. In another part of this chapter is made measurement voltage and current mode. There are measured functions as half- and full-wave rectifier. There are described parameters of rectifier from measured values. In the end are these values compared with values from simulations.