ASIC measurement system for TFT sensors

This paper focuses to design of a new monolithic ASIC for an integrated measurement TFT sensor system. This system exploits amperometric sensors. The sensor applies alumina substrate prepared by thick film technology. The ASIC prototype in CMOS 0.7 μm technology contains analog measurement block and programmable digital calibration EPROM memory on one chip. The conventional three-electrode potentiostat is connected to the working WE, reference RE, and auxiliary AE electrodes immersed in the tested chemical solution. The ASIC chip controls the potential of the working electrode with respect to the reference electrode while simultaneously measuring the current flowing between the working electrode and the auxiliary electrode. Note that the potentiostat´s internal feedback circuits prevent all but a very small current from flowing between the working and reference electrodes.