New architecture for an ultra low power and low noise PLL for biomedical applications

A new architecture for a non-continuous operation for frequency divider, frequency & phase detector and charge pump to design a low-power, low-phase noise and small size PLL for biomedical applications is introduced in this paper. This PLL operates in the Medical Implant Communication Service (MICS) frequency band and uses an ultra-low power ring VCO on 65nm CMOS technology. This ring oscillator VCO doesn´t need external inductor and capacitor like other LC oscillators and so requires very small die area. This VCO has two voltage control points. First control point has a wide tuning range for the coarse tuning and the second control point has a narrow tuning range for fine tuning within the MICS band frequency. This PLL exhibiting performance exceeding that of previously published designs.