Time saving EM-simulation method by using passive frame of DCO

This paper presents a simulation method for the DCO. EM simulations are essential and inevitable for modern LC oscillator design. Although EM-simulators provide high accuracy, the EM-simulation time is very long when metal-oxide-metal (MoM) capacitors are present. The proposed frame-based EM-simulation can significantly reduce the EM-simulation time even in the presence of MoM capacitors without influencing the accuracy. To verify the proposed method, a DCO was fabricated using a 55-nm CMOS process. Measurements of the DCO are in good agreement with the frame-based post-layout simulation results.