Title :
Spur-Reduction Frequency Synthesizer Exploiting Randomly Selected PFD
Author :
Te-Wen Liao ; Jun-Ren Su ; Chung-Chih Hung
Author_Institution :
Dept. of Electr. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
3/1/2013 12:00:00 AM
Abstract :
This brief presents a low-spur phase-locked loop (PLL) system for wireless applications. The low-spur frequency synthesizer randomizes the periodic ripples on the control voltage of the voltage-controlled oscillator to reduce the reference spur at the output of the PLL. A novel random clock generator is presented to perform the random selection of the phase frequency detector control for the charge pump in locked state. The proposed frequency synthesizer was fabricated in a TSMC 0.18-μm CMOS process. The proposed PLL achieved phase noise of -93 dBc/Hz with a 600-kHz offset frequency and reference spurs below -72 dBc.
Keywords :
CMOS analogue integrated circuits; clocks; frequency control; frequency synthesizers; phase control; phase locked oscillators; voltage control; voltage-controlled oscillators; PLL; TSMC CMOS process; charge pump; locked state; low-spur phase-locked loop system; periodic ripples; phase frequency detector control; random selected PFD; size 0.18 mum; spur-reduction frequency synthesizer; voltage-controlled oscillator; wireless applications; Charge pumps; Clocks; Frequency synthesizers; Generators; Phase locked loops; Phase noise; Voltage-controlled oscillators; Low spur synthesizer; phase-locked loop (PLL); voltage-controlled oscillator (VCO);
Journal_Title :
Very Large Scale Integration (VLSI) Systems, IEEE Transactions on
DOI :
10.1109/TVLSI.2012.2190118