Development of new conditioning circuit for ISFET sensor
Abstract
It is commonly known that most readout circuits of the pH-ISFET, with temperature cancelation, were designed using MOSFET working in strong regime. Nevertheless, a classes of circuits elaborated with respect to MOSFET operating in weak inversion and moderate regime are also suitable for low-power systems such as ISFET sensor array for DNA detection. In this work a new integrated interface circuit that can perform a great temperature compensation to enhance stability of the readout circuit operating in weak inversion for ISFET was developed. At first, the experimental results agree with the ISFET macro model in wide range of pH with a sensitivity about of 54 mV/pH. Second, we investigated the ISFET response for a wide temperature range from -20 °C to 150 °C. After that we propose a new conditioning circuit operating in weak inversion regime, the simulation result prove that the design technique permits to enhance the temperature insensitivity (about of 13 × 10<sup>-6</sup> V/°C) and a power consumption in order of 49 µW.
Event details
- Event
- tc19-2019