A 600 μW readout circuit with potentiostat for amperometric chemical sensors and glucose meter applications

This paper presents a low power electrochemical interface circuit for amperometric sensors. The readout circuit with potentiostat design maintains a constant bias potential between the reference and working electrodes using one operational transconductance amplifier (OTA) and four MOS transistors. Redox currents from 1 to 50 μA can be measured by the readout circuit with maximum nonlinearity of plusmn1 percent over the aforementioned range. The micro instrument has been implemented in 0.35 μm TSMC CMOS technology that consumes only 600 μW of power and occupies a small area of 0.16 mm². Chip test results emulate the simulation results with good agreement and confirm the effectiveness of the designed system.