US 7,321,111 B2
Method and system to enhance differential dynamic range and signal/noise in CMOS range finding systems using differential sensors
Cyrus Bamji, Fremont, Calif. (US); and Khaled Salama, Troy, N.Y. (US)
Assigned to Canesta, Inc., Sunnyvale, Calif. (US)
Filed on Dec. 28, 2006, as Appl. No. 11/648,062.
Application 11/648062 is a continuation in part of application No. 11/350209, filed on Feb. 08, 2006, granted, now 7,157,685.
Prior Publication US 2007/0158533 A1, Jul. 12, 2007
Int. Cl. H01L 27/00 (2006.01)
U.S. Cl. 250—214A  [250/214 R; 250/208.1] 20 Claims
OG exemplary drawing
 
1. A method to increase effective differential dynamic range of a differential pixel responsive to optical energy, a detection response V(t) of said differential pixel having a common mode component and a differential component, the method including:
(a) adding at least one compensating offset to avoid a saturation magnitude differential signal level; and
(b) recording effective sum of compensating offsets added to avoid said saturation magnitude;
wherein effective value of said differential signal V(t) is proportional to VOUT ±K·(effective sum of said compensating offsets), where K is a constant.