TY - GEN
T1 - Integrated multipurpose analog front-end for electrochemical ISFET sensors
AU - Hefele, Markus
AU - Mullner, Ernst
AU - Brederlow, Ralf
AU - Losel, Andreas
AU - Meier, Sebastian
AU - Pfeffer, Christian
AU - Kreupl, Franz
AU - Wolf, Bernhard
N1 - Publisher Copyright:
© 2019 IEEE.
PY - 2019/6
Y1 - 2019/6
N2 - Ion-Sensitive-Field-Effect-Transistors (ISFETs) are an alternative to the common glass electrode for pH sensing. They promise higher integration, easier manufacturing and are interesting for biological, medical and environmental applications. However, they require a different and slightly more complex readout circuit. We propose a new circuit based on a standard mixed-signal-processor with minimal required external components. The operating point of the ISFET is set with a servo loop in software using only the integrated DACs and opamps and an external resistor. With the internal ADC, feedback is provided for the software loop and the result is read. We compare this method with a fully analog ISFET readout circuit and show their equivalence. The new circuit provides some additional features, such as run time configurable operating point and channel type settings. The integrated MCU can also perform calibration and sensor diagnosis functionality and eases the integration in other systems and parallel operation of many units with its digital interfaces.
AB - Ion-Sensitive-Field-Effect-Transistors (ISFETs) are an alternative to the common glass electrode for pH sensing. They promise higher integration, easier manufacturing and are interesting for biological, medical and environmental applications. However, they require a different and slightly more complex readout circuit. We propose a new circuit based on a standard mixed-signal-processor with minimal required external components. The operating point of the ISFET is set with a servo loop in software using only the integrated DACs and opamps and an external resistor. With the internal ADC, feedback is provided for the software loop and the result is read. We compare this method with a fully analog ISFET readout circuit and show their equivalence. The new circuit provides some additional features, such as run time configurable operating point and channel type settings. The integrated MCU can also perform calibration and sensor diagnosis functionality and eases the integration in other systems and parallel operation of many units with its digital interfaces.
KW - ISFET
KW - analog front-end
KW - electro-chemical measurement
KW - sensor controller
UR - http://www.scopus.com/inward/record.url?scp=85078932915&partnerID=8YFLogxK
U2 - 10.1109/NEWCAS44328.2019.8961291
DO - 10.1109/NEWCAS44328.2019.8961291
M3 - Conference contribution
AN - SCOPUS:85078932915
T3 - 17th IEEE International New Circuits and Systems Conference, NEWCAS 2019
BT - 17th IEEE International New Circuits and Systems Conference, NEWCAS 2019
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 17th IEEE International New Circuits and Systems Conference, NEWCAS 2019
Y2 - 23 June 2019 through 26 June 2019
ER -