An Autofocus Sensor With Global Shutter Using Offset-Free Frame Memory

Autor:	Jung Han Choi, Bongsub Song, Jinwook Burm, Nayeon Cho, Younglok Kim, Byunghoon Kim
Rok vydání:	2010
Předmět:	Autofocus Engineering CMOS sensor Correlated double sampling business.industry Amplifier Electrical engineering law.invention Programmable-gain amplifier Sensor array law Shutter Electronic engineering Electrical and Electronic Engineering Image sensor business
Zdroj:	IEEE Transactions on Circuits and Systems II: Express Briefs. 57:878-882
ISSN:	1558-3791 1549-7747
Popis:	An autofocus (AF) sensor with global shutters using offset-free frame memory is presented. A cross-shaped AF sensor array has left and right horizontal arrays and top and bottom vertical arrays. AF is achieved by calculating the phase difference from the digital code of the light illumination difference between the left and right (or top and bottom) arrays. The global shutter was implemented by using offset-free frame memories for accuracy enhancement. The proposed offset-free frame memories consist of flip-around sample-and-hold amplifiers with correlated double sampling. An active pixel sensor array, offset-free frame memories, a programmable gain amplifier, a 10-bit pipelined analog-to-digital converter, and digital control circuits are fully integrated on the chip fabricated on the 0.18-μm CMOS image sensor technology. It occupies 7 × 8 mm2 with bonding pads. Each active pixel size is 15 × 100 μm2. The total power consumption of the AF sensor is 660 mW at 3.3-V supply voltage.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::5b989d531082b73689f09587fb3450cb https://doi.org/10.1109/tcsii.2010.2082951 Zobrazit plný text záznamu