Disclosed herein is a touch screen controller operable with a touch screen having force lines and sense lines. The touch screen controller includes drive circuitry driving the force lines with a force signal in a touch data sensing mode and not driving the force lines in a noise sensing mode. Sense circuitry senses data at the sense lines in the touch data sensing mode and the noise sensing mode. Processing circuitry samples the data, multiplies the data by a sine multiplier to produce imaginary data, sums the imaginary data, multiplies the data by a cosine multiplier to produce real data, sums the real data, and determines magnitude values of the data as a function of the imaginary data and the real data.