A touch screen controller includes an input stage configured to receive and condition a touch output from a touch matrix to produce a touch signal. An accumulation stage is configured to receive the touch signal and accumulate the touch signal to produce an accumulated output. The accumulated output is digitized by an analog to digital converter to produce a touch strength value. A given amount of charge is subtracted from or added to accumulated output during a next accumulation if the touch strength value is greater than an upper threshold or less than a lower threshold. This avoids saturation of components in the touch screen controller and therefore increases the signal to noise ratio.