A readout channel for applications to X-ray diffraction imaging at free electron lasers has been developed in a 65 nm CMOS technology. The analog front-end circuit can achieve an input dynamic range of 100 dB by leveraging a novel signal compression technique based on the non-linear features of MOS capacitors. Trapezoidal shaping is accomplished through a transconductor and a switched capacitor circuit, performing gated integration and correlated double sampling. A small area, low power 10 bit successive approximation register (SAR) ADC, operated in a time-interleaved fashion, is used for numerical conversion of the amplitude measurement. Operation at 5 MHz of the analog channel including the shaper was demonstrated. Also, the channel was found to be compliant with single 1 keV photon resolution at 1.25 MHz. The ADC provides a signal-to-noise ratio (SNR) of 56 dB, corresponding to an equivalent number of bits (ENOB) of 9 bits, and a differential non linearity DNL<1 LSB at a sampling rate slightly larger than 1.8 MHz.

A 2D imager for X-ray FELs with a 65 nm CMOS readout based on per-pixel signal compression and 10 bit A/D conversion

RIZZO, GIULIANA;BATIGNANI, GIOVANNI;BETTARINI, STEFANO;CASAROSA, GIULIA;FORTI, FRANCESCO;PALADINO, ANTONIO;PAOLONI, EUGENIO;
2016

Abstract

A readout channel for applications to X-ray diffraction imaging at free electron lasers has been developed in a 65 nm CMOS technology. The analog front-end circuit can achieve an input dynamic range of 100 dB by leveraging a novel signal compression technique based on the non-linear features of MOS capacitors. Trapezoidal shaping is accomplished through a transconductor and a switched capacitor circuit, performing gated integration and correlated double sampling. A small area, low power 10 bit successive approximation register (SAR) ADC, operated in a time-interleaved fashion, is used for numerical conversion of the amplitude measurement. Operation at 5 MHz of the analog channel including the shaper was demonstrated. Also, the channel was found to be compliant with single 1 keV photon resolution at 1.25 MHz. The ADC provides a signal-to-noise ratio (SNR) of 56 dB, corresponding to an equivalent number of bits (ENOB) of 9 bits, and a differential non linearity DNL<1 LSB at a sampling rate slightly larger than 1.8 MHz.
Ratti, L.; Comotti, D.; Fabris, L.; Grassi, M.; Lodola, L.; Malcovati, P.; Manghisoni, M.; Re, V.; Traversi, G.; Vacchi, C.; Rizzo, Giuliana; Batignani, Giovanni; Bettarini, Stefano; Casarosa, Giulia; Forti, Francesco; Giorgi, M.; Morsani, F.; Paladino, Antonio; Paoloni, Eugenio; Pancheri, L.; Dalla Betta, G. F.; Mendicino, R.; Verzellesi, G.; Xu, H.; Benkechkache, M. A.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/822090
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