DocumentCode :
1188865
Title :
A Low-Leakage Open-Loop Frequency Synthesizer Allowing Small-Area On-Chip Loop Filter
Author :
Jonsson, Fredrik ; Olsson, Håkan
Author_Institution :
Radio Electron. Lab., R. Inst. of Technol. (KTH), Stockholm
Volume :
56
Issue :
3
fYear :
2009
fDate :
3/1/2009 12:00:00 AM
Firstpage :
195
Lastpage :
199
Abstract :
A frequency synthesizer targeting low-power packet-based frequency-shift-keying (FSK) applications using open-loop modulation of the oscillator is presented. Unlike conventional implementations, the proposed synthesizer is open both when transmitting and receiving data. It is, therefore, possible to use a wide loop-filter bandwidth without violating the noise or spurious requirements. A wideband loop-filter can be implemented using small component values, allowing an on-chip loop filter. To handle the frequency drift associated with open-loop implementations, a low-leakage charge pump is proposed. The synthesizer is implemented using a 0.18-mum CMOS process. The total power consumption is 9 mW, and the circuit area including the voltage-controlled oscillator (VCO) inductors and on-chip loop-filter is 0.32 mm2. The measured frequency drift indicates a leakage current of below 2 fA.
Keywords :
filters; frequency shift keying; frequency synthesizers; oscillators; frequency drift; leakage current; low-leakage open-loop frequency synthesizer; low-power packet-based frequency-shift-keying; onchip loop filter; open-loop modulation; voltage-controlled oscillator; wide loop-filter bandwidth; Frequency modulation; frequency stability; frequency synthesizers; leakage currents; phase locked loops; phase noise; transceivers;
fLanguage :
English
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-7747
Type :
jour
DOI :
10.1109/TCSII.2009.2015366
Filename :
4799192
Link To Document :
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