Peter Aronhime

A current conveyor realization using operational amplifiers

A second generation current conveyor realization is presented that employs only operational amplifiers and resistors. No additional devices are required. The frequency limitations of the circuit are described, and the results of the applications of the circuit are provided.

Alternative Realizations of CMOS Current Feedback Amplifiers for Low Voltage Applications

Two variants of a new current feedback amplifier (CFA) are presented in this paper. These CFAs are realized in CMOS technology and both are capable of working at low voltages. It is shown that one circuit performs better than the other by virtue of an increased impedance at its Z terminal achieved through the use of additional transistors. Analysis of both variants of the current conveyor and buffer that form the current feedback amplifier gives an insight into the location of primary poles and zeros of the CFAs. Simulation results indicate an overall gain bandwidth product in excess of 59 MHz and 102 MHz for each circuit at a gain of −10 and with a 3.3 V supply. Experimental results from a chip fabricated in a 0.35 μm CMOS technology agree closely with the simulation results.

A novel CMOS first-order all-pass filter

A novel first-order all-pass filter is proposed. Consisting of level shifters and two passive components, the circuit uses just six transistors to achieve desired phase shifts at near unity gain in a 3.3 V, 0.35 μm CMOS process. Experimental results using 4007 ICs confirm the operation of the circuit.

Practical voltage/current-controlled grounded resistor with dynamic range extension

In response to Prof. Senani comments to our paper entitled ‘Practical voltage/current controlled grounded resistor with dynamic range extension’, we wish to state that we were not aware of his previous work done in this area as referenced by his supplied list of references. We ourselves had a long list of references as much work has been done in this area. For this, the authors thank him for drawing it to our attention, given his work relies upon the same technique ‘Bisection of the drain-to-source voltage of the FET’. As such we would have cited it had we been aware of it. Therefore we welcome his drawing his previous work to our attention.

Cascadable Current-Mode Biquads

New procedures are presented that yield cascadable, opamp based current-mode biquads from voltage-mode biquads without the use of voltage-mode to current-mode transformations. The opamps in the resulting current-mode circuits can be replaced by current-mode devices, such as current conveyors, producing circuits that are fully current-mode. The procedures are applied to several multi-opamp voltage-mode circuits to achieve current-mode lowpass, highpass, bandpass, notch, and allpass filters. The procedures are also applied to a single opamp circuit. Experimental results are given.

Realization of current-mode complex pole all-pass networks using a single current conveyor

A current-mode all-pass circuit which utilizes a first-generation current conveyor (CCI) as the only active element is derived. This circuit is useful in its own right, but it also demonstrates that the CCI offers an advantage in the realization of current-mode circuits containing only one current conveyor and no other active devices. Higher-order all-pass circuits can be constructed by cascading the circuits. The circuits sensitivities and gain-bandwidth limitations on their performance are calculated, and laboratory results are presented.<<ETX>>

Feedforward neural networks for estimating IC parametric yield and device characterization

A unique and accurate approach for modeling semiconductor device characteristics and estimating IC parametric yield is described. Multilayer perceptron neural networks (MLPNN) are trained using error back propagation to model DC device characteristics measured at the final fabrication stage. Measurements of material and/or device characteristics taken at earlier fabrication stages are used to develop neural network models of the final DC parameters. A very good agreement has been found between the actual measurements and the MLPNN modeled parameters, and the resulting yield estimations are in excellent agreement with the actual yield.

A Novel Hybrid Active Inductor

In this brief, a novel hybrid inductor is proposed. The circuit is a hybrid of an operational amplifier and a current conveyor with three passive elements, and offers advantages over conventional current conveyor implementations in its ability to produce high quality factor inductors. Experimental and PSPICE simulation results are presented which verify the theoretical derivations.

A novel differential high-frequency CFA integrator

A new differential integrator implemented using current feedback amplifiers (CFAs) is presented in this paper. The resulting integrator is stable and does not employ a capacitor in the negative feedback path of the CFA for its operation. Experimental results taken from AD844 CFAs authenticate the viability of the proposed integrator.

A new configuration for current feedback operational amplifiers

A new realization of a Current Feedback Amplifier (CFA) is introduced, and a description of its properties is provided. It is shown that this new realization offers several advantages in comparison with conventional CFAs and may be useful in certain design applications. Theoretical derivations are presented, stability issues are examined, and laboratory measurement results are given.