Multi-parameter low-power-consumption current-mode ion sensitive field effect tube array sensor device

Abstract

The invention discloses a multi-parameter low-power-consumption current-mode ion sensitive field effect tube array sensor device which comprises an n*n ISFET (ion sensitive field effect tube) sensor array, a matrix selection switch for selecting ISFETs, an address decoder, a reference transistor (REFET) for temperature and common-mode drift compensation, a normal-phase current transmitter, an anti-phase current transmitter, a current mode analog-digital converter (ADC) and a voltage analog-digital converter (DAC). ISFETs, selected by an address selector, of a grid coverage sensitive film and REFETs, selected by the address selector, of a grid coverage passivation film form differential geminate transistors, and the current difference outputted by the differential geminate transistors is converted by the ADC into a digital voltage signal to be outputted. Compared with a voltage mode circuit, the device adopting a current mode detection circuit can work under low working voltage, and is low in circuit power consumption and large in dynamic range; in addition, by adopting the differential detection ways, the imbalance and the temperature drift of the device can be effectively inhibited; meanwhile, the non-ideal characteristics of an ISFET sensor, such as long-term drift, can be effectively compensated.

Description

technical field [0001] The invention relates to an ion-sensitive field-effect tube sensor, especially a multi-parameter low-power current mode ion-sensitive field-effect tube array sensor device, which is used for detection of various biochemical ion parameters, detection of ion concentration gradients in solutions, and ion Differential current mode detection of sensitive field effect transistors, and compensation control of ion sensitive field effect transistor sensors. Background technique [0002] Ion-sensitive field-effect transistor (ISFET) has a similar structure to metal oxide semiconductor MOSFET (Metal Oxide Silicon Field Effect Transistor), except that the gate of MOSFET is replaced by solution and ion-sensitive film, which passes through different sensitive film materials on the gate. It reacts directly with the ions in the solution to be tested, and then can be used to detect multiple biochemical indicators. It has the dual characteristics of both electrochemica...

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Problems solved by technology

[0005] Because the pH value of the electrolyte to be tested will also change with temperature, and the electrical characteristics of ISFET are sensitive to temperature, such as the sensitive membrane-solution interface potential will change with temperature, and the threshold voltage of ISFET will also change with temperature. Secondly, due to the parameter The fluctuation of the voltage on the electrode will affect the measurement of the ISFET

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