  The planned IceCube-Upgrade will enhance the capability of IceCube in the
detection of GeV-scale neutrino physics and enable an improved measurement of
the properties of the glacial ice. Three types of new optical sensors will be
deployed during the Upgrade: PDOM, D-Egg, and mDOM. Since the design of the
PDOM and D-Egg are very similar, the development of the front-end electronics
for the two optical sensors has been merged. The photo-electron signals
detected by the PMTs are digitized with high-speed ultra-low power ADCs and
processed in an FPGA, before being sent to the data acquisition system located
on the surface of the South-Pole glacier. The almost final revision of the
front-end electronics is equipped with the common microcontroller unit and the
communication daughter board for simplifying the communication scheme for the
three different modules. This contribution focuses on the design of the
front-end electronics and presents first results from the performance tests.
