Large bandwidth op-amp based white noise current source

2014 ◽  
Vol 85 (2) ◽  
pp. 024702 ◽  
Author(s):  
Gino Giusi ◽  
Graziella Scandurra ◽  
Carmine Ciofi
Keyword(s):  
White Noise ◽  
Current Source ◽  
Noise Current ◽  
Op Amp ◽  
Large Bandwidth

Programmable, very low noise current source

2014 ◽  
Vol 85 (12) ◽  
pp. 125109 ◽  
Author(s):  
G. Scandurra ◽  
G. Cannatà ◽  
G. Giusi ◽  
C. Ciofi
Keyword(s):  
Current Source ◽  
Low Noise ◽  
Noise Current

The response of a spatially distributed neuron to white noise current injection

1979 ◽  
Vol 33 (1) ◽  
pp. 39-55 ◽  
Author(s):  
Frederic Y. M. Wan ◽  
Henry C. Tuckwell
Keyword(s):  
White Noise ◽  
Current Injection ◽  
Noise Current ◽  
Spatially Distributed

scholarly journals Designing a High-Precision AC Current Source to Measure the nm-Scale Displacements in Mechanical Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Lanto Rasolofondraibe ◽  
Bernard Pottier ◽  
Xavier Chiementin
Keyword(s):  
High Precision ◽  
Internal Control ◽  
Current Source ◽  
Contactless Measurement ◽  
Control Loop ◽  
Output Impedance ◽  
Op Amp ◽  
High Impedance ◽  
Ac Current ◽  
Bearing Raceway

Measuring the dynamics of a continuously moving target, at the nanoscale level, such as of a bearing raceway or any other vibrating element, requires a contactless measurement. A mission that can be easily carried out by a capacitive probe. The current flowing through the sensor has to remain constant regardless of the changes in the sensors’ output impedance. In this manner, the voltage across the probe is proportional to the distance between the probe and the target. However, the high impedance of the probe cannot be disregarded in comparison to the output impedance of the Howland source. To overcome this problem, we designed a voltage-controlled AC current source (VCCS). The new design consists of implementing two nested loops and uses two cascaded controllers, a fast but imprecise internal control loop tuned by a slow but precise outer control loop in order to obtain a high-precision AC output current. The performance of this device has been compared with the improved quad op-amp current source (IQOA). The results obtained during the numerical validation confirm the relevance of this device.

An Improved SPICE Macromodel of Memristor for General Applications

2013 ◽  
Vol 303-306 ◽  
pp. 1854-1858 ◽  
Author(s):  
Guo Hua Liu ◽  
Guang Yi Wang
Keyword(s):  
Wireless Communication ◽  
High Frequency ◽  
Current Source ◽  
Op Amp ◽  
Spice Model ◽  
Great Performance ◽  
Dependent Sources ◽  
Two Parameters ◽  
Resistance Value ◽  
Amplitude Characteristics

This paper introduces an improved SPICE model of memristor using dependent sources and switches. The proposed SPICE model with two parameters in dependent current source has ideal frequency and amplitude characteristics. We simulate two circuits with memristor. The results demonstrate that the memristor can “remember” last resistance value when no current passes through it, the Amplitude Modulation (AM) circuit with memristor and op-amp is simulated under the condition of high frequency. Since the memristor has great performance in frequency there might be a possible application of the memristor to be used as modulator or demodulator in wireless communication.

Distributed Selection of the Optimal Sizes of Analog Unity Gain Cells by Fuzzy Set Intersection

2015 ◽  
pp. 180-209
Author(s):  
Said Polanco-Martagón ◽  
Gerardo Reyes Salgado ◽  
Georgina Flores Becerra ◽  
Esteban Tlelo Cuautle
Keyword(s):  
Fuzzy Sets ◽  
Distributed System ◽  
Circuit Simulation ◽  
Current Source ◽  
Oxide Semiconductor ◽  
Large Bandwidth ◽  
Set Intersection ◽  
Voltage Follower ◽  
Unity Gain ◽  
Feasible Solutions

A distributed system based on Fuzzy sets to select the optimal sizes of Unity Gain Cells (UGCs) is introduced. A zoom technique is also introduced to search for the optimal sizes in a more refined way. The selected sizes accomplish target specifications established by linguistic variables, namely gain “closer to” unity and “large” bandwidth, which are represented by fuzzy sets. The case of study is focused on three Voltage Follower and a CFOA whose performance characteristics are evaluated by using IC technology of 0.35µm and 180µm, respectively, and the circuit simulation program SPICE. Every circuit is codified by the width and large (W/L) of every Metal-Oxide-Semiconductor Field-Effect-Transistor (MOSFET) and by its bias current source. From the population of feasible solutions computed by evolutionary algorithms, the optimal W/L sizes are selected by the proposed distributed system through the intersection of fuzzy sets.

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