Optical sensor arrangement and method for light sensing

US11029197B2 · kind B2 · utility

Assignee

• AMS AG · AT

Inventors

• Bernhard Greimel-Längauer · Graz, AT
• Peter Bliem · Premstätten, AT

Key dates

• Filing date: Jun 8, 2018
• Grant date: Jun 8, 2021
• Expiry date: Jul 1, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J2001/446
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An optical sensor arrangement has an integrator, a photodiode for providing a current corresponding to a first polarity, a comparator coupled to the integrator for comparing a voltage with a threshold voltage to provide a comparison output, a reference charge circuit and a control unit. The reference charge circuit is coupled to the integrator for selectively providing first charge packages of a first size or second charge packages of a second size. The control unit is configured to control operation in a calibration phase, in an integration phase and in a residual measurement phase. During the calibration phase, the reference charge circuit provides one of the first charge packages and one or more of the second charge packages to the integrator until the comparison output changes. A reference number is determined corresponding to a number of the second charge packages provided. During the integration phase, the photodiode is connected to the integrator and the reference charge circuit provides one of the first charge packages to the integrator in response to a respective change of the comparison output. An integration number corresponding to a number of the changes of the comparis…