Prototype Design of the Readout System for N ν DEx-100 Experiment

N $\nu $ DEx is an upcoming neutrino-less double-beta decay experiment. A first small-scale prototype, named N $\nu $ DEx-100, features a readout plane with a 0.9 m diameter situated at one end-cap of its time projection chamber (TPC). This plane hosts around 10000 charge measurement sensors requiring dedicated readout electronics. This paper introduces the prototype design of the readout electronics and its integration with the back-end data acquisition (DAQ) system, which is composed of dedicated firmware and software to handle the system control and data readout. In the front-end, the demonstration system is developed to house 19 sensors along with the necessary supporting circuitry. The functionality and performance of the entire demonstration system with Topmetal-S sensors are evaluated, and the ion measurement capability of the system has been confirmed by tracking particles irradiated from the 241Am $\alpha $ source.