Abstract: A new low power, low phase jitter, compact realization, and self-biased PLL, which is fabricated on SMIC 40 nm CMOS technology is introduced.The proposed self-biased PLL eliminates extra band gap biasing circuits, and internally generates all the biasing voltages and currents.Meanwhile, all of the PLL dynamic loop parameters, such as loop bandwidth, natural frequency, damping factors are kept constant adaptively.By optimizing the circuit structures, the perfect unity of chip estate, power dissipation, phase jitter, and loop stability is achieved.The PLL consumes 4.2 mW of power under 1.1 V/2.5 V voltage supply at 2.4 GHz VCO frequency, while occupying a die area of less than 0.02 mm² (180×110 μm²), and the typical period jitter (RMS) is around 2.8 ps.

Key words: self-biased PLL, ring VCO, low power, compact area