The creation of devices that control the transfer of information in optical systems with the highest data transfer rates is an urgent task and involves both scientific research and experimental development. The paper analyzes circuit solutions and obtains simulation results for voltage controlled oscillator (VCO) circuits and the entire PLL system (PLL). The main components of the PLL: phase detector (PD), VCO and counter-frequency divider (C-FD) are implemented using classical CMOS circuitry. The solutions we proposed in our work for implementing components on CMOS transistors with design standards of 90 and 65 nm allowed us to implement a frequency synthesizer model that allows us to ensure the operation of on-board devices for OFDM and MIMO technologies, which are used in optical systems for high-speed data transmission.