System-level considerations for the front-end readout ASIC in the CBM experiment from the power supply perspective

Abstract

A: New fixed target experiments using high intensity beams with energy up to 10 AGeV from the SIS100 synchrotron presently being constructed at FAIR/GSI are under preparation. Most of the readout electronics and power supplies are expected to be exposed to a very high flux of nuclear reaction products and have to be radiation tolerant up to 3 MRad (TID) and sustain up to 10 14 /cm 2 of 1 MeV neutron equivalent in their life time. Moreover, the mostly minimum ionising particles under investigation leave very little signal in the sensors. Therefore very low noise level amplitude measurements are required by the front-end electronics for effective tracking. Sensor and interconnecting micro-cable capacitance and series resistance in conjunction with intrinsic noise of the charge sensitive amplifier are dominant noise sources in the system. However, the singleended architecture of the amplifiers employed for the charge processing channels implies a potential problem with noise contributions from power supply sources. Strict system-level constraints leave very little freedom in selecting a power supply structure optimal with respect to: power efficiency, cooling capabilities and power density on modules, but also noise injection to the front-end via the power supply lines. Design of the power supply and distribution system of the Silicon Tracking System in the CBM experiment together with details on the front-end ASICs (STS -XYTER2) and measurement results of power supply and conditioning electronics (selected DC/DC converter and LDO regulators) are presented. K: Voltage distributions; Front-end electronics for detector readout; Radiation-hard electronics 1Corresponding author.

Prototype single-ended and pseudo-differential charge processing circuit for micro-strip silicon and gaseous sensors read-out

“…The high-frequency noise can compromise the system noise performance by increasing the ENC value. In tracking detectors, L-C filtration of the analog supplies can not be applied due to the high magnetic field in the experimental area [12]. Moreover, the linear regulators often need to be custom-designed, where radiation strengthening takes precedence over ultra-low noise performance or high PSRR.…”

Leakage current-induced effects in the silicon microstrip and gas electron multiplier readout chain and their compensation method

“…The presence of leakage current in detection systems is unavoidable and is related mainly to the sensor performance, some external elements, such as long cables [6], PCB fan-out and package (if used) but also to the ESD protection circuits, which in certain conditions can dominate [7]. The protection circuit is important to protect the electronics against a static discharge during the STS module assembly and partially against sparks when working with GEM detectors (in this case additional, external protection will be mandatory) [8].…”