A sample and hold system, for capturing and reading at least one input signal. The system comprises a readout device, a controller, an array of segments comprising a plurality of unit cells and a dummy unit cell, and segment switches between the segments and the readout device. The controller is adapted for controlling the system such that: during an acquisition phase a trace of samples is taken from the input signal and held in the unit cells; during a readout phase the samples in the unit cells or in the dummy unit cells of a segment are read out by readout device; after opening or closing the segment switches the dummy unit cell, is the first cell which is read out by the readout device.