A 32-channel ASIC for X-Ray detectors

In this paper we present a 32-channel integrated circuit (ASIC) designed for a multi-anode silicon drift detector for X-ray imaging and spectroscopy (0.5 ÷ 100 keV). The ASIC includes 32 read-out front-end channels (ROC), each consisting of a low-noise preamplifier, a second-order RC-CR pulse shaper, a peak stretcher, an amplitude and a peak discriminator, as well as a reset and pile-up rejection circuit. The ASIC includes also a digital configuration register, supporting daisy-chain connection, for setting the ROC parameters for signal processing. At room temperature the equivalent noise charge is 18 e^2212;_rms and the linearity error is lower than ±5% over the complete input range. The ASIC has been designed in a 0.35-μm CMOS technology with a 3.3-V power supply. A single ROC occupies an area of 200 × 380 μm². The area of the whole ASIC is 6500 × 2260 μm² and the power consumption is 0.4 mW per channel.