VTH -Extractors Based Readout Circuit of ISFET with Temperature Compensation

-This paper proposes a novel readout circuit of ion sensitive field effect transistor (ISFET) with temperature compensation using two threshold voltage (V_TH) extractor circuits. The first V_TH extractor with ISFET gives the pH reading and the second V_TH extractor with depletion-type MOSFET (DMOSFET) provides the temperature compensation. The entire circuit uses only 20 transistors and dissipates a power of 889.3 muW. This design offers a sensitivity of 54 mV/pH and an improved temperature coefficient (T.C.) of 0.02 mV/degC.