This work is concerned with the design and the experimental characterization of analog front-end electronics conceived for experiments with unprecedented particle rates and radiation levels at future high-energy physics colliders. A prototype chip integrating different test structures has been submitted in the framework of the CHIPIX65 project. These structures are standalone channels for the readout of hybrid pixels, featuring a charge sensitive preamplifier as the first stage of the readout chain, a high-speed comparator and a circuit for fine threshold tuning. The paper thoroughly discusses the results, mainly focused on the charge sensitive amplifier, coming from the characterization of the submitted test structures.