Low-noise and low-power front-end in 130 nm CMOS for triple-GEM detectors supporting wide range of detector capacitances with gain and peaking time programmability

An analog front-end in 130 (nm) CMOS technology was developed for the readout of triple-GEM detectors in the CMS experiment at CERN. The front-end has programmable peaking time - 15, 25, 35 and 45 (ns) - and gain - 48, 16.4 and 8.6 (mV/fC) - and is able to support a detector capacitance ranging from 0 to 120 (pF). In the design, many optimization techniques have been used to minimize the power consumption for given noise and timing requirements. Consequently, a single front-end channel consumes 790 (μA), and achieves an equivalent noise chargeof 620 (e-) at 0 (pF) detector capacitance with a noise slope of 33 (e-/pF). In order to simplify the peaking time programmability, an OTA-C based shaperwas used in the analog chain. The entire design hasbeen made radiation hard against TID. A chip comprising 129 front-end channels was fabricated and tested.