  CUORE is an array of thermal calorimeters composed of 988 crystals held at
about 10 mK, whose absorbed energy is read out with semiconductor thermistors.
The composition of the crystal is TeO2, and the aim is the study of the double
beta decay of 130Te on very long and stable runs. CUPID-0 is an array of 26
Zn82Se crystals with double thermistor readout to study the double beta decay
of 82Se. In the present paper, we present an overview of the entire front-end
electronic readout chain, from the preamplifier to the anti-aliasing filter.
This overview includes motivations, design strategies, circuit implementation
and performance results of the electronic system, including other auxiliary yet
important elements like power supplies and the slow control communication
system. The stringent requirements of stability on the very long experimental
runs that are foreseen during CUORE and CUPID-0 operation, are achieved thanks
to novel solutions of the front-end preamplifier and of the detector bias
circuit setup.
