SCARLET: Readout ASIC for Bump-bonded SDD Array for Large Event Throughput

SCARLET is a novel readout ASIC implemented for integration with arrays of monolithic Silicon Drift Detectors (SDD) by means of bump bonding. It targets high-rate high-density energy-dispersive X-ray detection systems in synchrotron beamlines and industrial applications. The ASIC integrates a reset-type Charge Sensitive Amplifier (CSA), 7
^th
order semi-Gaussian shaping amplifier, peak stretcher equipped with peak detector circuit and optimum pile up rejection scheme, analog memory to enhance throughput, and on-chip SAR ADC, shared between two pixels with sparse multiplexing scheme. The chip layout is compatible for bump bonding assembly with 2×2, 2 mm pitch, square SDD array. It occupies a total area of 7 mm × 3.8 mm, and average power consumption is 56 mW/pixel. For spectroscopic performance, SCARLET is expected to reach an output count rate density of 25 Mcps/cm
²
simultaneously with ENC below 20e
⁻
. In this paper are presented the results from the chip noise characterization when wedge bonded to SDD, and also the first results of SDD-SCARLET bump bonding assembly.