METHOD TO OPERATE AN OPTICAL SENSOR ARRANGEMENT WITH IMPROVED CONVERSION ACCURACY AND OPTICAL SENSOR ARRANGEMENT

摘要

An optical sensor arrangement comprises a photodiode and a converter arrangement including an integration amplifier (2), a comparator amplifier (3), an integration capacitor (C_INTH) and a result register (6).During a precharge phase the result register (6) is set to a starting value. During an integration phase a current is sampled through the photodiode (1) to update the result register (6) in response to down charges applied to an input of the integration amplifier. During a residue phase the result register (6) is updated in dependence on the charge remaining on the integration capacitor (C_INTH). Measuring the residual charge increases resolution and accuracy of the converter.