An electrochemical sensor ASIC for agriculture applications

This paper presents a fully integrated application specific integrated circuit (ASIC) for the readout of multiple electrochemical sensor signals. It consists of an analog router that routes readout circuits to various sensors, a 10bit successive approximation register analog to digital converter (SAR ADC), two digital to analog converters (DAC), a multiplexer and I2C/SPI serial interfaces for connection to micro-controller (MCU). The ASIC is fabricated in a 0.35-μm CMOS technology, occupies an area of 1.5 × 3.0 mm², and consumes a current of 3.2 mA from a 3.3 V supply. All calibration and configurations are set using the I2C/SPI serial interface connections.