A CMOS image sensor with light-controlled oscillating pixels for an investigative optobionic retinal prosthesis system

摘要

This paper presents a high-dynamic range CMOS image sensor architecture incorporating light-controlled oscillating pixels which can act as front-end for an investigative optobionic retinal prosthesis research effort. Each pixel acts as an independent oscillator, whose frequency is proportional to the local light intensity. A 9 × 9 pixel array has been fabricated in the AMS 0.35 μm CMOS opto process. Each pixel's area amounts to 160 × 160μm~2, each pixel photodiode area is 20 × 20μm~2 while the array occupies 2.89 mm~2. Measured results show that the sensor can achieve a linear optical dynamic range of 80 dB (from 0.24 Hz to 2.2 kHz). Its linear electrical dynamic range exceeds 134 dB (from 100 mHz to 502 kHz). The nominal power dissipation is about 50 nW per pixel.