Method for light-to-frequency conversion and light-to-frequency converter arrangement

A light-to-frequency converter arrangement, comprising:

• an analog-to-digital converter arrangement comprising a sensor input for connecting a photodiode, and a result output for providing a digital comparator output signal, and
• a signal processing unit connected to the result output of the analog-to-digital converter arrangement;
• wherein
• the analog-to-digital converter arrangement is operated depending on a first clock signal,
• the analog-to-digital converter arrangement is adapted to convert a photocurrent generated by the photodiode upon illumination with a light source into the digital comparator output signal,
• the signal processing unit is adapted to determine from the digital comparator output signal a first count and a second count, where the first count comprises an integer number of counts and the generation of the first count depends on the first clock signal, and where the second count relates to the time interval between at least two counts of the first count,
• the signal processing unit comprises a logic/calculation engine which receives the first count and the second count and which calculates a digital output signal from the first count and the second count, and
• the digital output signal is indicative of the frequency of a repeating pattern in the intensity of electromagnetic radiation emitted by the light source and detected by the photodiode.