Characterization of 128 × 128 MM-PAD-2.1 ASIC: a fast framing hard x-ray detector with high dynamic range

• Published in: Journal of instrumentation 2022-03, Vol.17 (3), p.P03003
• Main Authors: Gadkari, D., Shanks, K.S., Hu, H., Philipp, H.T., Tate, M.W., Thom-Levy, J., Gruner, S.M.
• Format: Article
• Language: English
• Subjects: Application specific integrated circuits; Arrays; Dynamic range; Electronic detector readout concepts (solid-state); Front-end electronics for detector readout; Hybrid detectors; MATERIALS SCIENCE; OTHER INSTRUMENTATION; Pixels; Sensors; Synchrotrons; X ray detectors; X ray sources; X-rays
• ISSN: 1748-0221; 1748-0221
• DOI: 10.1088/1748-0221/17/03/P03003

We characterize a new x-ray Mixed-Mode Pixel Array Detector (MM-PAD-2.1) Application Specific Integrated Circuit (ASIC). Using an integrating pixel front-end with dynamic charge removal architecture, the MM-PAD-2.1 ASIC extends the maximum measurable x-ray signal (in 20 keV photon units) to > 10 7  x-rays/pixel/frame while maintaining a low read noise across the full dynamic range, all while imaging continuously at a frame rate of up to 10 kHz. The in-pixel dynamic charge removal mechanism prevents saturation of the input amplifier and proceeds in parallel with signal integration to achieve deadtime-less measurements with incident x-ray rates of > 10 10 x-rays/pixel/s. The ASIC format consists of 128 × 128 square pixels each 150 μm on a side and is designed to be 3-side buttable so large arrays can be effectively tiled. Here we use both laboratory x-ray sources and the Cornell High Energy Synchrotron Source (CHESS) to characterize two single ASIC prototype detectors for both low (single x-ray) and high incident flux detection. In the first detector the ASIC was solder bump-bonded to a 500 μm thick Si sensor for efficient detection of x-rays below  20 keV, whereas the second detector used a 750 μm thick CdTe sensor for x-rays above ∼ 20 keV.