Abstract: A CMOS light detector configured to detect specific wavelengths of light includes a first sensor and a second sensor. The first sensor includes CMOS photocells that are covered by a colored filter layer of a first color that has a first transmittance that allows both light of the specific wavelengths and light of other wavelengths to pass. The second sensor including further CMOS photocells, at least some of which are covered by both a colored filter layer of the first color and a colored filter layer of a second color, stacked one above the other in either order, where the colored filter layer of the second color has a second transmittance that allows light of the other wavelengths to pass. The first sensor produces a first photocurrent, and the second sensor produces a second photocurrent, when light including both the specific and other wavelengths is incident upon the detector.

Abstract: Provided herein are circuits and methods to generate a voltage proportional to absolute temperature (VPTAT) and/or a bandgap voltage output (VGO). A circuit includes a group of X transistors. A first subgroup of the X transistors are used to produce a first base-emitter voltage (VBE1). A second subgroup of the X transistors are used to produce a second base-emitter voltage (VBE2). The VPTAT can be produced by determining a difference between VBE1 and VBE2. Which of the X transistors are in the first subgroup and used to produce the first base-emitter voltage (VBE1), and/or which of the X transistors are in the second subgroup and used to produce the second base-emitter voltage (VBE2), change over time. Additionally, a circuit portion can be used to generates a voltage complimentary to absolute temperature (VCTAT) using at least one of the X transistors. The VPTAT and the VCTAT can be added to produce the VGO.