A method of calibrating a pixelated radiation detector containing a plurality of pixel detectors electrically connected to a plurality of respective read-out channels of detector read-out circuitry includes determining a sensor material deadtime, τsensor, for each of the plurality of pixel detectors, and adjusting the respective read-out channel deadtime, τASIC, based on the determined sensor material deadtime, τsensor, of the respective one of the plurality of pixel detectors, such that a total deadtime, τtotal of each pixel detector including a sum of the respective sensor material deadtime, τsensor, and the respective read-out channel deadtime, τASIC, varies by less than ±5% from each other.