  We present the design and characterization of TIGER (Turin Integrated Gem
Electronics for Readout), a 64-channel ASIC developed for the readout of the
CGEM (Cylindrical Gas Electron Multiplier) detector, the proposed inner tracker
for the 2018 upgrade of the BESIII experiment, carried out at BEPCII in
Beijing. Each ASIC channel features a charge sensitive amplifier coupled to a
dual-branch shaper stage, optimized for timing and charge measurement, followed
by a mixed-mode back-end that extracts and digitizes the timestamp and charge
of the input signals. The time-of-arrival is provided by a set of low-power
TDCs, based on analogue interpolation techniques, while the charge measurement
is obtained either from the Time-over-Threshold information or with a
sample-and-hold circuit. The ASIC has been fabricated in a 110 nm CMOS
technology and designed to operate with a 1.2 V power supply, an input
capacitance of about 100 pF, an input dynamic range between 3 and 50 fC, a
power consumption of about 12 mW/channel and a sustained event rate of 60
kHz/channel. The design and test results of TIGER first prototype are presented
showing its full functionality.
