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US 11,761,817 B2Granted
Optical sensor arrangement including a dummy photodiode with a well that surrounds a well of a photodiode
Assigneeams International AG
InventorGonggui Xu
Life of this patent
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Abstract
An optical sensor arrangement includes a photodiode, a dummy photodiode, an analog-to-digital converter, a first switch which couples the photodiode to an input of the analog-to-digital converter, and a second switch which couples the dummy photodiode to the input of the analog-to-digital converter.
Claims11
An optical sensor arrangement, comprising
- a photodiode,
- a dummy photodiode,
- a charge balancing analog-to-digital converter,
- a first switch which couples the photodiode to an input of the charge balancing analog-to-digital converter,
- a second switch which couples the dummy photodiode to the input of the charge balancing analog-to-digital converter,
- at least a further photodiode,
- at least a further charge balancing analog-to-digital converter,
- at least a further first switch which couples the further photodiode to an input of the further charge balancing analog-to-digital converter,
- at least a further second switch which couples the dummy photodiode to the input of the further charge balancing analog-to-digital converter, and
- a logic circuit,
- wherein the charge balancing analog-to-digital converter is designed to generate a digital output signal with a first value representing a value of a dummy current of the dummy photodiode in a reference phase and to generate the digital output signal with a second value representing a value of a photodiode current of the photodiode in a measurement phase,
- wherein the dummy photodiode is covered by a light shielding cover and wherein a second well of the dummy photodiode surrounds a first well of the photodiode, and
- wherein the logic circuit is configured to calculate an optical signal by multiplying the first value of the digital output signal by a factor and then subtracting a result of the multiplying from the second value of the digital output signal.
10 more elements
A method for optical sensing, comprising
- generating a dummy current by a dummy photodiode,
- providing the dummy current to a charge balancing analog-to-digital converter in a reference phase,
- determining a first value of a digital output signal as a function of the dummy current by the charge balancing analog-to-digital converter,
- generating a photodiode current by a photodiode,
- providing the photodiode current to the charge balancing analog-to-digital converter in a measurement phase,
- determining a second value of the digital output signal as a function of the photodiode current by the charge balancing analog-to-digital converter, and
- generating an optical signal by multiplying the first value of the digital output signal by a factor and then subtracting a result of the multiplying from the second value of the digital output signal,
- wherein the dummy photodiode is covered by a light shielding cover and wherein a second well of the dummy photodiode surrounds a first well of the photodiode.
5 more elements
An optical sensor arrangement, comprising
- a photodiode,
- a dummy photodiode,
- a charge balancing analog-to-digital converter,
- a first switch which couples the photodiode to an input of the charge balancing analog-to-digital converter,
- a second switch which couples the dummy photodiode to the input of the charge balancing analog-to-digital converter,
- a logic circuit,
- wherein the charge balancing analog-to-digital converter is designed to generate a digital output signal with a first value representing a value of a dummy current of the dummy photodiode in a reference phase and to generate the digital output signal with a second value representing a value of a photodiode current of the photodiode in a measurement phase,
- wherein the dummy photodiode is covered by a light shielding cover and wherein a second well of the dummy photodiode surrounds a first well of the photodiode, and
- wherein the logic circuit is configured to calculate an optical signal by multiplying the first value of the digital output signal by a factor and then subtracting a result of the multiplying from the second value of the digital output signal.
6 more elements
Dependencies are inferred from the claim text.