Development of an ASIC for multi-readout X-ray CCDs

摘要

We have developed application specific integrated circuits (ASICs) for multi-readout X-ray CCDs in order to improve their time resolution. ASICs with the size of 3 mm × 3 mm were fabricated by employing a Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 μm CMOS technology. The number of channels is 4 and the each channel consists of a preamplifier, 5-bit DAC and delta-sigma analog-to-digital converters (ADCs). The measured equivalent input noise at the pixel rate of 19.5 kHz and 625 kHz are 36 μV and 51 μV, respectively. The power consumption is about 110mW/chip at 625 kHz pixel rate, which is about 10 times lower than that of our existing system. We now expect to employ an ASIC as the readout system of X-ray CCD camera onboard the next Japanese X-ray astronomy satellite. We tested the readout of the prototype X-ray CCDs by using ASICs and the total-dose effects of ASICs. We describe the overview of our ASICs and test results.