DocumentCode :
1051051
Title :
Time-to-Digital Converter for Frequency Synthesis Based on a Digital Bang-Bang DLL
Author :
Zanuso, Marco ; Madoglio, Paolo ; Levantino, Salvatore ; Samori, Carlo ; Lacaita, Andrea L.
Author_Institution :
Dipt. di Elettron. e Inf., Politec. di Milano, Milan, Italy
Volume :
57
Issue :
3
fYear :
2010
fDate :
3/1/2010 12:00:00 AM
Firstpage :
548
Lastpage :
555
Abstract :
This paper presents the design of a time-to-digital converter (TDC) suitable for a 3.5-GHz all-digital phase-lock loop (PLL). The converter is based on a digital bang-bang delay-lock loop, which allows constant resolution over process and temperatures spreads, avoids an off-chip filter and guarantees fast lock. The clock rate of the digital filter is scaled down by eight from the 3.5-GHz input to allow its implementation with standard cells. The occurrence of a limit cycle is analytically predicted and properly minimized, and its effect on the PLL phase noise is discussed. The circuit fabricated in 90-nm CMOS entails 16 delay stages, which lock to the input frequency in the 2.9-3.9-GHz range (limited by the available signal source). The delay of each TDC cell can be controlled with 50-fs step and the TDC time resolution is 16 ps at 3.9 GHz. The power consumption ranges between 8.1 and 16.5 mW, respectively. The limit-cycle-induced spur is below - 50 dBc. The area occupation is 0.032 mm2.
Keywords :
CMOS integrated circuits; analogue-digital conversion; digital filters; digital phase locked loops; frequency synthesizers; microwave circuits; nanofabrication; CMOS; circuit fabrication; clock rate; digital bang-bang DLL; digital filter; frequency 2.9 GHz to 3.9 GHz; frequency 3.5 GHz; frequency synthesis; limit cycle; limit-cycle-induced spur; phase-lock loop; power 8.1 mW to 16.5 mW; size 90 nm; standard cells; time-digital converter; Analog–digital conversion; CMOS; bang–bang control; delay-lock loops (DLLs); limit cycles; time-to-digital conversion;
fLanguage :
English
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-8328
Type :
jour
DOI :
10.1109/TCSI.2009.2023945
Filename :
5061570
Link To Document :
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