Title :
A novel current-mode readout circuit for ISFET sensor
Author :
Chunhua, Wang ; Yan, Zhao
Author_Institution :
Sch. of Comput. & Commun., Hunan Univ., Changsha
fDate :
Nov. 30 2008-Dec. 3 2008
Abstract :
This paper presents a novel differential current mode readout circuit for the ion sensitive field effect transistor (ISFET) as a pH sensor. It uses two second generation current conveyers (CCII), and provides an output current that is linearly sensitive to pH over a wide range (pH 2-12). It is more suitable for A/D conversion compared to voltage output circuits. The circuit is operating in differential mode, reference field effect transistor (REFET) is used to realize temperature compensation. The proposed readout circuit has simple structure, it uses only one type of active element (i.e. CCII), so that, it can be easy integrated on one chip and fabricated using a conventional CMOS process. Simulation results demonstrate the proposed circuit is well working and can be suitable used as an ISFET pH sensor readout circuit.
Keywords :
chemical sensors; current conveyors; ion sensitive field effect transistors; pH measurement; readout electronics; ISFET sensor; differential current mode readout circuit; ion sensitive field effect transistor; pH sensor; reference field effect transistor; second generation current conveyers; CMOS process; CMOS technology; Chemical sensors; Circuit simulation; Computational modeling; Electrodes; FETs; MOSFET circuits; Temperature sensors; Voltage;
Conference_Titel :
Circuits and Systems, 2008. APCCAS 2008. IEEE Asia Pacific Conference on
Conference_Location :
Macao
Print_ISBN :
978-1-4244-2341-5
Electronic_ISBN :
978-1-4244-2342-2
DOI :
10.1109/APCCAS.2008.4746046
