In an embodiment a method for operating a gas sensor arrangement includes generating a sensor current by a gas sensor, converting the sensor current into a digital comparator output signal in a charge balancing operation depending on a first clock signal, determining from the digital comparator output signal an asynchronous count comprising an integer number of counts depending on the first clock signal, determining from the digital comparator output signal a fractional time count depending on a second clock signal and calculating from the asynchronous count and from the fractional time count a digital output signal which is indicative of the sensor current generated by the gas sensor.