A frontend ASIC for a silicon avalanche photodiode linear array detector for synchrotron X-ray experiments

We designed a frontend ASIC of a silicon avalanche-photodiode (Si-APD) array detector for time-resolved measurements using pulsed synchrotron X-rays. The Si-APD detector had 64 pixels of a linear array. A pixel size of 100 μm by 200 μm with a 50-μm gap between pixels, a thickness of 10 μm and a sensitive region of 9.6 mm long were designed in the linear array. In order to apply the APD detector to time-resolved diffraction measurements with 2-ns pulse-pair resolving time and a count rate of up to >; 10⁷ s^-1, a four-channel ASIC of 4×4 mm² in size was newly developed for processing a nanosecond-width pulse from each pixel of the Si-APD. The ASIC consisted of a current amplifier with a baseline restorer, a comparator, T-flip flops and PECL drivers.