Spectroscopic Performance of TERA: Fast Multichannel Analog Pulse Processor ASIC for X-ray Detection Applications

This work reports the spectroscopic performance of the latest release of TERA (Throughput Enhanced Readout ASIC), a multichannel analog pulse processor (APP) ASIC suitable for detectors in ultra-high rate X-ray detection applications (>1Mcps/channel). The chip has been developed to process signals coming from Silicon Drift Detectors (SDDs) coupled with resettype Charge Sensitive Amplifiers (CSA). The demonstrator chip is composed of 4 parallel readout channels, each channel is composed by 7
^th
-order semi-Gaussian shaping-amplifier with adjustable shaping times and dynamic range, followed by a peak stretcher and an analog memory. Each pair of channels can be optionally digitized by 12-bit on-chip ADC, providing the maximum sampling frequency up to 2.5MHz. TERA architecture enables to achieve simultaneously high throughput and satisfactory energy resolution. In
⁵⁵
Fe spectroscopy measurements using SDD collimated to 4mm diameter, at the shortest pulse width of 200ns, FWHM Mn-Ka line of 171.5eV and 205.1eV were obtained at input rate 10kcps and 1.61Mcps, respectively. At 1.61Mcps input rate, 1.09Mcps throughput was achieved. High-rate performances are, to our knowledge, the best ones for a Spectroscopy analog ASIC and are close to the ones achievable with standard DPPs. Therefore, TERA can represent an attractive detector pulse processing solution for high-density multichannel detection systems.