CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Performance of the load-in-the-loop single Op-Amp voltage Controlled current source from the Op-Amp Parameters

Raul Macias ; Fernando Seoane (Institutionen för signaler och system, Medicinska signaler och system) ; Ramon bragos
Journal of Physics: Conference Serie (1742-6596). Vol. 224 (2010), 1, p. 12008.
[Konferensbidrag, refereegranskat]

In recent years, Electrical Bioimpedance (EBI) methods have gained importance. These methods are often based on obtaining impedance spectrum in the range of β-dispersion, i.e. from a few kHz up to some MHz. To measure EBI a constant current is often injected and the voltage across the tissue under study is recorded. Due to the performance of the current source influences the performance of the entire system, in terms of frequency range, several designs have been implemented and studied. In this paper the basic structure of a Voltage-Controlled Current Source based on a single Op-Amp in inverter configuration with a floating load, known as load-in-the-loop current source, is revisited and studied deeply. We focus on the dependence of the output impedance with the circuit parameters, i.e. the feedback resistor and the inverter-input resistor, and the Op-Amp main parameters, i.e. open loop gain, CMRR and input impedance. After obtaining the experimental results, using modern Op-Amps, and comparing to the theoretical and simulated ones, they confirm the design under study can be a good solution for multi-frequency wideband EBI applications because of higher values of the output impedance than 100kΩ at 1MHz are obtained. Furthermore, an enhancement of the basic design, using a current conveyor as a first stage, is proposed, studied and implemented.

Nyckelord: Current Source, EBIS, spectroscopy

Den här publikationen ingår i följande styrkeområden:

Läs mer om Chalmers styrkeområden  

Denna post skapades 2011-01-24.
CPL Pubid: 136034


Läs direkt!

Länk till annan sajt (kan kräva inloggning)

Institutioner (Chalmers)

Institutionen för signaler och system, Medicinska signaler och system (2005-2017)


Informations- och kommunikationsteknik
Elektronisk mät- och apparatteknik
Övrig annan teknik

Chalmers infrastruktur