  The XAA1.2 is a custom ASIC chip for silicon microstrip detectors adapted by
Ideas for the SuperAGILE instrument on board the AGILE space mission. The chip
is equipped with 128 input channels, each one containing a charge preamplifier,
shaper, peak detector and stretcher. The most important features of the ASIC
are the extended linearity, low noise and low power consumption. The XAA1.2
underwent extensive laboratory testing in order to study its commandability and
functionality and evaluate its scientific performances. In this paper we
describe the XAA1.2 features, report the laboratory measurements and discuss
the results emphasizing the scientific performances in the context of the
SuperAGILE front-end electronics.
