title: Improved Circuits with Capacitive Feedback for Readout Resistive Sensor Arrays.
abstract: One of the most suitable ways of distributing a resistive sensor array for reading is an array with M rows and N columns. This allows reduced wiring and a certain degree of parallelism in the implementation, although it also introduces crosstalk effects. Several types of circuits can carry out the analogue-digital conversion of this type of sensors. This article focuses on the use of operational amplifiers with capacitive feedback and FPGAs for this task. Specifically, modifications of a previously reported circuit are proposed to reduce the errors due to the non-idealities of the amplifiers and the I/O drivers of the FPGA. Moreover, calibration algorithms are derived from the analysis of the proposed circuitry to reduce the crosstalk error and improve the accuracy. Finally, the performances of the proposals is evaluated experimentally on an array of resistors and for different ranges.
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. oballe@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. oballe@uma.es.
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Oballe-Peinado
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. fvidal@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. fvidal@uma.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Vidal-Verdú
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. jsd@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. jsd@uma.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Sánchez-Durán
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. julian@elca.uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. julian@elca.uma.es.
authors.forename: Julián
authors.initials: J
authors.lastname: Castellanos-Ramos
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. jahidalgo@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. jahidalgo@uma.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Hidalgo-López
keywords: FPGAs; direct sensor-to-digital device interface; parallel analogue data acquisition; resistive sensor arrays
references.citation: Sensors (Basel). 2011;11(3):3249-66
references.pmid: 22163797
references.citation: Sensors (Basel). 2011;11(5):5489-507
references.pmid: 22163910