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US 11,703,385 B1Granted
Light sensor with dark current elimination having duo switch-capacitor circuits and a reverse capacitor
AssigneeLuxsentek Microelectronics Corp.
InventorsWen-Sheng Lin, Sheng-Cheng Lee, Yueh-Hung Ho, Chih-Wei Lin, Chen-Hua Hsi
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Abstract
The present invention provides a light sensor with dark current elimination. A dark current from a covered photodiode and a sensed current from a photodiode are respectively transformed to a dark voltage and a sensed voltage by a controlled integration circuit. A reverse capacitor receives the dark voltage and the sensed voltage to cancel out for each other, and outputs a corrected sensing voltage.
Claims6
A light sensor with dark current elimination, comprising:
- a first switch-capacitor circuit for converting a dark current of a first photodiode, without being exposed to ambient light, into a first voltage;
- a second switch-capacitor circuit for converting a sensing current of a second photodiode, with being exposed to the ambient light, into a second voltage;
- and
- a reverse capacitor connected to a first switch-capacitor circuit and the second switch-capacitor circuit, wherein the reverse capacitor inverts the first voltage to deduct the first voltage from the second voltage, and generates an output voltage (VOUT).
1 more element
Dependencies are inferred from the claim text.