This paper presents a novel current-mode instrumentation amplifier (CMIA) that utilizes an operational floating current conveyor (OFCC) as a basic building block. The OFCC, as a current-mode device, shows flexible properties with respect to other current- or voltage-mode circuits. The advantages of the proposed CMIA are threefold. First, it offers a higher differential gain and a bandwidth that is independent of gain, unlike a traditional voltage-mode instrumentation amplifier. Second, it maintains a high common-mode rejection ratio (CMRR) without requiring matched resistors, and finally, the proposed CMIA circuit offers a significant improvement in accuracy compared to other current-mode instrumentation amplifiers based on the current conveyor. The proposed CMIA has been analyzed, simulated, and experimentally tested. The experimental results verify that the proposed CMIA outperforms existing CMIAs in terms of the number of basic building blocks used, differential gain, and CMRR.

A novel current-mode instrumentation amplifier based on operational floating current conveyor

In this paper, a voltage-mode full-wave rectifier employing plus-type second-generation current conveyors (CCII+s) and enhancement-mode n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is proposed. The presented circuit requires no passive components, and is suitable for high frequency applications. The proposed full-wave rectifier circuit is simulated using HSPICE to verify the theoretical analysis.

Full-wave rectifier realization using only two CCII+s and NMOS transistors

This paper analyzes the performance of a family of high-quality precision full-wave rectifiers that utilize operational conveyors. The circuits have high precision, wide bandwidth, and high accuracy and are superior to the corresponding operational-amplifier (op amp)-based circuits. Using the LF351 op amp, they are able to rectify signals up to 100 kHz and beyond with little or no distortion. PSPICE results for the circuits are presented.

Versatile Precision Full-Wave Rectifiers for Instrumentation and Measurements

In this study, a novel voltage-mode full-wave rectifier with high-input impedance using a dual-X second-generation current conveyor and three enhancement-type n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is introduced. The proposed circuit does not employ any passive elements, and is simulated using SPICE program with level 49, 0.25 µm TSMC CMOS technology parameters to confirm the theory and exhibit the performance of the circuit.

A new full-wave rectifier circuit employing single dual-X current conveyor

A novel second-generation current conveyor (CCII)-based resistance-capacitance (RC) sinusoidal oscillator operating over a wide dynamic range is described. The oscillation condition and the oscillation frequency can be adjusted independently by two control resistors. The circuit proposed makes use of grounded capacitors and is suitable for implementation with the commercially available integrated circuit chip AD844 from Analog Devices which implements a CCII+. The circuit enjoys low sensitivities and is suitable for integration. Experimental results are given, showing close agreement with the theoretical conclusions.

Novel RC sinusoidal oscillator using second-generation current conveyor

This paper describes a simple and versatile current-mode full-wave precision rectifier circuit using AD844 from Analog Devices. The proposed scheme avoids the use of closely matched resistors and matched current mirrors. The circuit is easy to design and construct from readily available low-cost components and provides excellent precision rectifier performance over a wide band and wide input voltage range. Experimental results are included.

Current-mode precision rectification

A new five-port general purpose analogue building block, termed as an operational floating current conveyor (OFCC), is described. The OFCC combines the features of current feedback (CFB) operational amplifier, second generation current conveyor and operational floating conveyor (OFC). A simple implementation scheme of the OFCC is described and its terminal operational characteristics are used to yield a working model. The OFCC is then used as a single block to realize the four main amplifier types and the current conveyors (CCII+ and CCII-). Computer simulation results are presented and discussed. >

M. Abou El-Ela

Papers

Current-mode precision rectification

Operational floating current conveyor: characteristics, modelling and applications