The Borexino read out electronics and trigger system

In this document, we present the design and the implementation of the electronic system for the Borexino experiment, which is devoted to the measurement of the 7Be solar neutrino flux. The system is directly connected to the detector photomultipliers (PMT): for each of these the arrival time and the collected charge for the single light pulse is measured. The complete system is composed of the following: a front-end stage, which performs an analog processing of the PMT signal; a readout stage, used to digitize and store the signal processed by the front end and to measure the arrival time and the charge of each light pulse coming from the detector; a trigger stage, used to identify interesting events. In the following, a detailed description of each of the preceding stages is given.