A CMOS Interface Circuit Design for a 32-level Resolution Light Sensor

A new design of interface circuit for CMOS Light sensor for pH monitoring applications is presented here. The proposed design is useful to read color (wavelength) values with the help of a photodiode and outputs a digital word representing the color value. It operates by continuously comparing analog voltage output from an optical transducer against a pre-stored reference levels in two cascaded stages.The design provides few advantages such as faster speed; less power consumption; higher resolution with smaller number of storage units; and small area for on-chip integration. A simulation result implementing 32 levels of resolution is presented.