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

Cornell Affiliated Author(s)


D. Gadkari
K.S. Shanks
H. Hu
H.T. Philipp
M.W. Tate
J. Thom-Levy
Sol Gruner


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 > 107 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 > 1010 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. © 2022 IOP Publishing Ltd and Sissa Medialab.

Date Published


Journal of Instrumentation








Group (Lab)

Sol M. Gruner Group

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