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.