A fast monolithic active pixel sensor with pixel-level reset noise suppression and binary outputs for charged particle detection

In order to develop precision vertex detectors for the future linear collider, fast monolithic active pixel sensors are studied. A standard CMOS 0.25 mu m digital process is used to design a test chip which includes different pixel types' column-level discriminators, and a fully programmable digital sequencer. In-pixel amplification is implemented together with double sampling. Different charge-to-voltage conversion factors were obtained using amplifiers with different gains or diode sizes. Pixel architectures with dc and ac coupling to charge sensing element were proposed. Hits from conversion of Fe-55 photons were recorded for the dc-coupled and ac-coupled pixel versions. Double sampling is functional and allows almost a complete cancellation of fixed pattern noise.