Optically isolated current source

• Type: Article in International Conference Proceedings Book
• Date: 2009

Authors

Borges, E (Author) Other; Figueiras, E (Author) Other; Pereira, HC (Author) Other; Cardoso, JM (Author) Other; Ferreira, LR (Author) Other; Correia, C (Author) Other

Conference proceedings International

Title: WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING, VOL 25, PT 4: IMAGE PROCESSING, BIOSIGNAL PROCESSING, MODELLING AND SIMULATION, BIOMECHANICS

Pages: 2020-2023

World Congress on Medical Physics and Biomedical Engineering

Munich, GERMANY, SEP 07-12, 2009

Indexing

Scopus - 1 Citation

Other information

Authenticus ID: P-007-SSH

DOI: 10.1007/978-3-642-03882-2-536

Abstract (EN): This work addresses two different issues associated with the design voltage controlled current sources (VCSS): galvanic isolation between the load and the control voltage and loss of performance due to operational amplifier common mode rejection ratio (CMRR) degradation with frequency. Concerning isolation, we describe one solution, based on linear optocouplers, that provides isolation while preserving signal transmission down to DC. As to the error imparted to the output current by CMMR degradation, a Howland based design is analyzed, both, theoretically and by simulation, proving the possibility of compensating this error. A modification of the basic circuit is proposed and studied, demonstrating its capability to dramatically reducing the effect of CMRR error and, ultimately, extending the useful frequency range of the source.

Language: English

Type (Professor's evaluation): Scientific