The Gassiplex0.7-2 Integrated Front-End Analog Processor for the HMPID and the Dimuon Spectrometer of ALICE

The most recent member of the Gasplex family of ASICs has been designed in a 0.7 µm n-well CMOS process to meet specifications for the ALICE applications: 500 fC linear dynamic range and a peaking time of 1.2 µs. Its internal circuitry is optimized for the readout of gaseous detectors. A dedicated filter compensates the long hyperbolic signal tail produced by the slow drift of the ions and allows the shaper to achieve perfect return to the base line after 5 µs. Measurement of fabricated chips showed a noise performance of 530 e - rms at 0 pF external input capacitance and 1.2 µs peaking-time, with a noise slope of 11.2 e - rms/pF. The gain is 3.6 mv/fC over a linear dynamic range of 560 fC.