Quantum computation is bringing excitement and motivation into the scientific community to build a practical quantum computer. This would enable the solution of problems today intractable, thanks to the exponential decrease in the required number of operations with respect to a classical computer. Nevertheless, this extraordinary computer needs support from a classical computer to perform specific side tasks, such as quantum error correction, control and post-processing of the information where classical electronics is more efficient. Further, to enable the scalability of quantum computers reducing the huge amount of interconnections that are nowadays needed to perform quantum computation, classical electronics must be placed close to the quantum processor at cryogenic temperatures (4 K). To address this, firstly a compact model for simulation of CMOS at cryogenic temperature is proposed and secondly a CMOS Low-Noise Amplifier (LNA) is designed and tested at liquid Helium temperature (4 K). The cryoLNA is the first in this technology and will be employed in the RF electronic readout of spin qubit, replacing the existing discrete amplifier used in state-of-the-art experimental setup. The functionality of the CMOS LNA at deep cryogenic temperatures demonstrates the effectiveness of cryoCMOS and makes a first step towards the realization of integrated and scalable quantum computers.