Title :
Linear Current-Mode Active Pixel Sensor
Author :
Philipp, Ralf M. ; Orr, David ; Gruev, Viktor ; Van der Spiegel, Jan ; Etienne-Cummings, Ralph
Author_Institution :
Johns Hopkins Univ., Baltimore
Abstract :
A current mode CMOS active pixel sensor (APS) providing linear light-to-current conversion with inherently low fixed pattern noise (FPN) is presented. The pixel features adjustable-gain current output using a pMOS readout transistor in the linear region of operation. This paper discusses the pixel´s design and operation, and presents an analysis of the pixel´s temporal noise and FPN. Results for zero and first-order pixel mismatch are presented. The pixel was implemented in a both a 3.3 V 0.35 and a 1.8V 0.18 CMOS process. The 0.35 process pixel had an uncorrected FPN of 1.4%/0.7% with/without column readout mismatch. The 0.18 process pixel had 0.4% FPN after delta-reset sampling (DRS). The pixel size in both processes was 10times10 mum2, with fill factors of 26% and 66%, respectively.
Keywords :
CMOS analogue integrated circuits; CMOS image sensors; CMOS active pixel sensor; CMOS process; first-order pixel mismatch; fixed pattern noise; linear current-mode active pixel sensor; linear light-to-current conversion; pMOS readout transistor; pixel design; pixel operation; pixel temporal noise; size 0.35 micron; voltage 1.8 V; voltage 3.3 V; Active noise reduction; Analog integrated circuits; CMOS process; Circuit noise; Helium; Image sampling; Image sensors; Linearity; Pixel; Voltage; CMOS analog integrated circuits; image sensors;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2007.907168
