title: Low-voltage 96 dB snapshot CMOS image sensor with 4.5 nW power dissipation per pixel.
abstract: Modern "smart" CMOS sensors have penetrated into various applications, such as surveillance systems, bio-medical applications, digital cameras, cellular phones and many others. Reducing the power of these sensors continuously challenges designers. In this paper, a low power global shutter CMOS image sensor with Wide Dynamic Range (WDR) ability is presented. This sensor features several power reduction techniques, including a dual voltage supply, a selective power down, transistors with different threshold voltages, a non-rationed logic, and a low voltage static memory. A combination of all these approaches has enabled the design of the low voltage "smart" image sensor, which is capable of reaching a remarkable dynamic range, while consuming very low power. The proposed power-saving solutions have allowed the maintenance of the standard architecture of the sensor, reducing both the time and the cost of the design. In order to maintain the image quality, a relation between the sensor performance and power has been analyzed and a mathematical model, describing the sensor Signal to Noise Ratio (SNR) and Dynamic Range (DR) as a function of the power supplies, is proposed. The described sensor was implemented in a 0.18 um CMOS process and successfully tested in the laboratory. An SNR of 48 dB and DR of 96 dB were achieved with a power dissipation of 4.5 nW per pixel.
authors.affiliation: The VLSI Systems Center, LPCAS, Ben-Gurion University, P.O.B. 653, Be'er-Sheva 84105, Israel. spivakar@bgu.ac.il
authors.forename: Arthur
authors.initials: A
authors.lastname: Spivak
authors.forename: Adam
authors.initials: A
authors.lastname: Teman
authors.forename: Alexander
authors.initials: A
authors.lastname: Belenky
authors.forename: Orly
authors.initials: O
authors.lastname: Yadid-Pecht
authors.forename: Alexander
authors.initials: A
authors.lastname: Fish
mesh_terms: D004867:Equipment Design; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008670:Metals / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D012666:Semiconductors; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D059629:Signal-To-Noise Ratio
chemical_list: D008670:Metals; D010087:Oxides
keywords: CMOS; SNR; image sensor; low power; snapshot; strong inversion; sub-threshold; wide dynamic range