US 6,982,406 B2
Simple CMOS light-to-current sensor
Pao Jung Chen, 20872 Sola St., Cupertino, Calif. 95014 (US)
Filed on Apr. 03, 2003, as Appl. No. 10/406,053.
Prior Publication US 2005/0258339 A1, Nov. 24, 2005
Int. Cl. H01L 31/00 (2006.01)
U.S. Cl. 250—214.1 10 Claims
OG exemplary drawing
 
1. A CMOS light-to-current sensor chip supported on a semiconductor substrate comprising:
a p-n junction photo-diode having a photo-current generating node;
a first MOS transistor functioning as a transistor load having a drain terminal and a gate terminal connected to the photo-current generating node of said p-n junction photo-diode, and a source terminal connected to a voltage supplying node; and
a second MOS transistor functioning as a current-mirror transistor of said first MOS transistor having a gate terminal connected to the gate terminal of said first MOS transistor, a source terminal connected to the source terminal of said first MOS transistor, and a drain terminal for outputting a substantially linearly amplified current proportional to the photo-generated current of said photo-diode to an external resistor load.