Proceedings Article | 24 August 2017
L. Lodola, L. Ratti, D. Comotti, L. Fabris, M. Grassi, P. Malcovati, M. Manghisoni, V. Re, G. Traversi, C. Vacchi, G. Batignani, S. Bettarini, F. Forti, G. Casarosa, F. Morsani, A. Paladino, E. Paoloni, G. Rizzo, M. Benkechkache, G.-F. Dalla Betta, R. Mendicino, L. Pancheri, G. Verzellesi, H. Xu
Proc. SPIE. 10392, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XIX
KEYWORDS: Diffraction, Sensors, X-rays, X-ray sources, Image sensors, CMOS technology, Synchrotrons, X-ray imaging, X-ray detectors, Free electron lasers
The PixFEL collaboration has developed the building blocks for an X-ray imager to be used in applications at FELs. In particular, slim edge pixel detectors with high detection efficiency over a broad energy range, from 1 to 12 keV, have been developed. Moreover, a multichannel readout chip, called PFM2 (PixFEL front-end Matrix 2) and consisting of 32 × 32 cells, has been designed and fabricated in a 65 nm CMOS technology. The pixel pitch is 110 μm, the overall area is around 16 mm2. In the chip, different solutions have been implemented for the readout channel, which includes a charge sensitive amplifier (CSA) with dynamic signal compression, a time-variant shaper and an A-to-D converter with a 10 bit resolution. The CSA can be configured in four different gain modes, so as to comply with photon energies in the 1 to 10 keV range. The paper will describe in detail the channel architecture and present the results from the characterization of PFM2. It will discuss the design of a new version of the chip, called PFM3, suitable for post-processing with peripheral, under-pad through silicon vias (TSVs), which are needed to develop four-side buttable chips and cover large surfaces with minimum inactive area.
