Design of CMOS Monolithic Digitized Light Transducer With Calibration Technique for Ambient Light Sensor Applications

Abstract

In this paper, a CMOS monolithic digitized light transducer with a calibration technique for ambient light sensor applications is newly proposed. The output signal of the proposed light transducer is a pulse stream that it could be easily sent over a wide range of transmission media, such as package switch network, radio, optical, infra red, ultrasonic, etc. Another innovation is that the proposed calibration technique enhances and calibrates the linear error among light sensor arrays over a wide dynamic frequency range. The output frequency of the proposed chip ranges from 7.5 to 1.873 MHz and the dynamic range is 108 dB. Before performing the proposed calibration technique, the maximum linear errors of one photodiode versus 5 and 25 photodiodes are 17.38% and 56%, respectively. But, after calibrating, the maximum linear errors are reduced to 4.97% and 4.94%, respectively. All the functions and performance of the proposed CMOS monolithic digitized light transducer with the calibration technique for ambient light sensor applications are successfully tested and proven through measurements. The proposed chip is suitable for lighting instruments and ambient light sensor devices.