A Monolithic 32-channel Front-End and DSP ASIC for Gaseous Detectors

CERN is currently undergoing a major upgrade within the ALICE (A Large Ion Collider Experiment) detectors, one of the four main experiments at the LHC (Large Hadron Collider) accelerator. The LHC luminosity will increase making the heavy ions collision rate rise from 500 Hz to 50 kHz. Both the Time Projection Chamber (TPC) and Muon Chamber (MCH) detectors demand a new and faster readout electronics, which support continuous readout to cope with this higher rate. This paper presents the SAMPA (Serialized Analog-digital Multi Purpose ASIC) integrated circuit for upgrading the TPC and MCH front-end and signal processing of charge induced signals, addressing the higher data rate specification. The SAMPA comprises 32 equal channels, twice the present ALICE TPC readout circuitry capacity. Each channel is composed of a positive/ negative polarity Charge Sensitive Amplifiers, a Pulse Shaper and a 10-bit Analog to Digital Converter. It also integrates a full custom Digital Signal Processor, which receives data from 32 channels, compensate signal perturbations or distortion through several filters and transmits the processed data. Designed for TSMC 130nm CMOS process, the manufactured chip occupies an area of approximately 85mm2 and consumes about 8.3 mW per channel at nominal voltage supply of 1.25 V. The SAMPA is silicon proven and experimental test results have confirmed its functionality and suitability for the ALICE Upgrade (2019-2020).