Abstract
Systematic design of low-dropout-regulator (LDO) regulated low-phase-noise LC-tank voltage controlled oscillators (VCOs) is presented. Low-frequency sensitivity profile of power supply induced phase noise of a typical cross-coupled LC-tank VCO is investigated. The relationship between frequency pushing and power supply-induced phase noise is derived. Systematic codesign of VCO sensitivity to low-frequency supply noise with respect to an LDO output noise and power supply rejection profile is introduced. To demonstrate the design approach experimentally, two 2.4-GHz LC-tank VCOs with pMOS and nMOS switching devices powered by PFET LDOs are designed and fabricated on an 0.18-μm, 7-layer metal CMOS process. By using an integrated LDO, it is shown that the VCO phase-noise sensitivity to low frequency improves by 55 dB at 100-kHz offset.
Original language | English (US) |
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Pages (from-to) | 1834-1844 |
Number of pages | 11 |
Journal | IEEE Transactions on Circuits and Systems I: Regular Papers |
Volume | 55 |
Issue number | 7 |
DOIs | |
State | Published - Aug 2008 |
Keywords
- DC-DC power conversion
- Phase noise
- Power supply rejection (PSR)
- Voltage regulators
- Voltage-controlled oscillators (VCOs)
ASJC Scopus subject areas
- Electrical and Electronic Engineering