A low-leakage open-loop frequency synthesizer allowing small-area on-chip loop filter

Authors:
Fredrik Jonsson;Håkan Olsson
Affiliations:
Radio Electronics Laboratory, Royal Institute of Technology, Stockholm, Sweden;Radio Electronics Laboratory, Royal Institute of Technology, Stockholm, Sweden
Venue:
IEEE Transactions on Circuits and Systems II: Express Briefs
Year:
2009

Citing 1
Cited 1

Fundamentals of modern VLSI devices

Fundamentals of modern VLSI devices

A low-cost wireless interface with no external antenna and crystal oscillator for cm-range contactless testing

Proceedings of the 48th Design Automation Conference

Quantified Score

Hi-index	0.00

Visualization

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-µm 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.