A 160$\times$120-Pixels Range Camera With In-Pixel Correlated Double Sampling and Fixed-Pattern Noise Correction

Abstract

This paper presents the design and electro-optical test of a 160 × 120-pixels CMOS sensor specifically conceived for Time-Of-Flight 3D imaging. The in-pixel processing allows the implementation of Indirect Time-Of-Flight technique for distance measurement with reset noise removal through Correlated Double Sampling and embedded fixed-pattern noise reduction, whereas a fast readout operation allows the pixels values to be streamed out at a maximum rate of 10 MSample/s. The imager can operate as a fast 2D camera up to 458 fps, as a 3D camera up to 80 fps, or even coupling both operation modes. The chip has been fabricated using a standard 0.18 μm 1P4M 1.8 V CMOS technology with MIM capacitors. The resulting pixel has a pitch of 29.1 μm with a fill-factor of 34% and includes 66 transistors. Distance measurements up to 4.5 m have been performed with pulsed laser light, achieving a best precision of 10 cm at 1 m in real-time at 55 fps and 175 mA current consumption.