A circuit suitable for th ereadout of ultra tin pixel detectors at SLHC and Elsewhere

Hybrid pixel detectors provide unrivalled track finding capabilities for the LHC vertex detectors. Further reducing the material budget is of crucial importance among the many challenges which must be addressed by the vertex systems at the SLHC. Here we propose a two stage front-end readout architecture whereby the discrimination is performed on the sum of the total charge deposited in a number of pixels prior to readout of the analog or binary hit information per pixel. The readout concept is based on ideas developed in the framework of the Medipix3 project which aims to mitigate the effects of charge sharing in single photon processing systems. We indicate that it should be possible to obtain 100 % hit detection efficiency using a 50 μm thick Si detector segmented into pixels of 20 μm x 150 μm using a threshold of ~ 1 200 e-. The paper focuses on simulations of the new circuit architecture using planar sensors