Development of a High-Rate Front-End ASIC for X-Ray Spectroscopy and Diffraction Applications

We developed a new front-end application-specific integrated circuit (ASIC) to upgrade the Maia X-ray microprobe. The ASIC instruments 32 configurable channels that perform either positive or negative charge amplification, pulse shaping, peak amplitude, and time extraction along with buffered analog storage. At a gain of 3.6 V/fC, 1-mu s peaking time, and a temperature of 248 K, an electronic resolution of 13 and 10 e(-) rms was measured with and without a silicon drift detector (SDD) sensor, respectively. A spectral resolution of 170-eV full-width at half-maximum (FWHM) at 5.9 keV was obtained with an Fe-55 source. The channel linearity was better than +/- 1% with rate capabilities up to 40 kcps. The ASIC was fabricated in a commercial 250-nm process with a footprint of 6.3 mm x 3.9 mm and dissipates 167 mW of static power.