A CMOS digitized monolithic sun sensor transducer with calibration circuits for monitoring solar radiation of tomato crops

In this paper, a CMOS digitized monolithic sun sensor transducer with calibration circuits for monitoring solar radiation of tomato crops is newly proposed. Another innovation is that the outputs of the proposed chip are directly digitized, they could be easily sent over a wide range of transmission media, such as PSN, radio, optical, IR, ultrasonic, and etc. After performing the proposed calibration technique, the linear error is 1.63%. The output frequency is 0.7 to 1.82 MHz under varied solar radiation ranging from 68.9 to 188.7 W/m². The chip area is 1.5 × 1.5 mm². Based upon 0.35 μm 2P4M CMOS technology with 3.3 and 5 V power supply, all the functions and performance of the proposed technique are successfully proven through measurements and confirmed it to be applied on monitoring solar radiation of tomato crops.