XAMPS Detectors Readout ASIC for LCLS

Conference · Thu Dec 18 00:00:00 EST 2008

OSTI ID:944557

Dragone, A; Pratte, J F; Rehak, P; Carini, G A; Herbst, R; O'Connor, P; Siddons, D P

An ASIC for the readout of signals from X-ray Active Matrix Pixel Sensor (XAMPS) detectors to be used at the Linac Coherent Light Source (LCLS) is presented. The X-ray Pump Probe (XPP) instrument, for which the ASIC has been designed, requires a large input dynamic range on the order of 104 photons at 8 keV with a resolution of half a photon FWHM. Due to the size of the pixel and the length of the readout line, large input capacitance is expected, leading to stringent requirement on the noise optimization. Furthermore, the large number of pixels needed for a good position resolution and the fixed LCLS beam period impose limitations on the time available for the single pixel readout. Considering the periodic nature of the LCLS beam, the ASIC developed for this application is a time-variant system providing low-noise charge integration, filtering and correlated double sampling. In order to cope with the large input dynamic range a charge pump scheme implementing a zero-balance measurement method has been introduced. It provides an on chip 3-bit coarse digital conversion of the integrated charge. The residual charge is sampled using correlated double sampling into analog memory and measured with the required resolution. The first 64 channel prototype of the ASIC has been fabricated in TSMC CMOS 0.25 {micro}m technology. In this paper, the ASIC architecture and performances are presented.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 944557
• Report Number(s): SLAC-PUB-13463
• Conference Information: Contributed to 2008 IEEE Nuclear Science Symposium (NSS) and Medical Imaging Conference (MIC) and 16th International Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors (RTSD), Dresden, Germany, 18-25 Oct 2008
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ARCHITECTURE
CAPACITANCE
LIGHT SOURCES
LINEAR ACCELERATORS
OPTIMIZATION
Other
ENG
PHOTONS
PROBES
RESOLUTION
SAMPLING