Compact 0.3-to-1.125GHz self-biased phase-locked loop for system-on-chip clock generation in 0.18 mu m CMOS

摘要

In this paper, we propose a compact ring-oscillator-based self-biased phase-locked loop (SBPLL) for system-on-chip (SoC) clock generation. It adopts the proposed triple-well NMOS source degeneration voltage-to-current (V-I) converter instead of the operational amplifier (OPAMP) based V-I converter and a proposed simple start-up circuit with a negligible area to save power and area. The SBPLL is implemented in the 0.18 mu m CMOS process, and it occupies 0.048 mm(2) active core. The measurement results show the SBPLL can generate output frequency in a wide range from 300 MHz to 1.125 GHz with a constant loop bandwidth that is around 5MHz and a relatively low jitter performance that is less than 4.9 mUI over the entire covered frequency range. From -20 to 70 degrees C the rms jitter variation and loop bandwidth variation at 1.125 GHz are 0.2 ps and 350 kHz, respectively. The rms jitter performance variation of all covered frequency points is less than 10% in the supply range from 1.5 to 1.7 V. Such SBPLL shows robustness over environmental variation. The maximum power consumption is 5.6 mW with 1.6V supply at an output frequency of 1.125 GHz. (C) 2016 The Japan Society of Applied Physics