PixFEL project : hybrid High Dynamic Range X-ray image sensor for application at future FEL facilities

The goal of the pixFEL project is the realization of the sensors and readout circuits for large-area imagers to be used in future X-ray Free Electron Lasers facilities. In this paper the main application requirements are highlighted and the technological solutions adopted both in the sensor and in the readout electronics are discussed. Since the final detector will be composed by 4-side buttable tiles, active-edge sensors have been adopted to minimize the dead area at the borders of each tile. The in-pixel electronics includes a low-noise high-dynamic range preamplifier, a shaper performing Correlated Double Sampling operation and a 10-bit ADC. A 110-μm pitch pixel was designed in a 65nm process to provide single-photon detection at low photon counts, a dynamic range exceeding 90dB and 5Mfps burst frame rate.