Journal article
A study of phase noise in colpitts and LC-tank CMOS oscillators
This paper presents a study of phase noise in CMOS Colpitts and LC-tank oscillators. Closed-form symbolic formulas for the 1/f(2) phase-noise region are derived for both the Colpitts oscillator (either single-ended or differential) and the LC-tank oscillator, yielding highly accurate results under very general assumptions.
A comparison between the differential Colpitts and the LC-tank oscillator is also carried out, which shows that the latter is capable of a 2-dB lower phase-noise figure-of-merit (FoM) when simplified oscillator designs and ideal MOS models are adopted. Several prototypes of both Colpitts and LC-tank oscillators have been implemented in a 0.35-mu m CMOS process.
The best performance of the LC-tank oscillators shows a phase noise of -142 dBc/Hz at 3-MHz offset frequency from a 2.9-GHz carrier with a 16-mW power consumption, resulting in an excellent FoM of similar to 189 dBc/Hz. For the same oscillation frequency, the FoM displayed by the differential Colpitts oscillators is similar to 5 dB lower.
| Language: | English |
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| Publisher: | IEEE |
| Year: | 2005 |
| Pages: | 1107-1118 |
| ISSN: | 1558173x and 00189200 |
| Types: | Journal article |
| DOI: | 10.1109/JSSC.2005.845991 |
0.35 micron 1/f noise 16 mW 2.9 GHz 3 MHz Active noise reduction CMOS integrated circuits CMOS process Colpitts oscillators Energy consumption LC-tank CMOS oscillators MOS models Noise generators Noise level Phase noise Prototypes Radio frequency Semiconductor device modeling Voltage-controlled oscillators integrated circuit noise oscillation frequency
