A 900 MHz ISM band mash-12 fractional-n frequency synthesizer for 5-Mbps data transmission


Journal Article

The design of a fractional-N PLL in the 900 MHz ISM band is presented to enable 5-Mbps data transmission for neuro application using GMSK modulation. The frac-N PLL consists of a phase frequency detector (PFD), charge pump (CP), loop filter, LC-VCO, and a prescaler. To minimize the CP current, the VCO control node capacitance is used to realize the on-chip loop filter's 3rd pole. Measured results of the MASH-12 frac-N synthesizer at 925 MHz show a phase noise of -104dBc/Hz at 22.5 KHz offset, in-band rms phase error of 0.7deg over 2.25 MHz bandwidth and out-of-band rms phase error of 2.3 deg. The measured phase noise spectrum correlates well with behavioral noise model predictions, including noise due to CP and PFD non-linearities. The chip was designed in 1.8V TSMC0.18m Mixed Signal and RF process. Copyright 2007 ACM.

Full Text

Duke Authors

Cited Authors

  • Arora, H; Klemmer, N; Wolf, P

Published Date

  • October 1, 2007

Published In

  • Proceedings of the Acm Great Lakes Symposium on Vlsi, Glsvlsi

Start / End Page

  • 381 - 386

Digital Object Identifier (DOI)

  • 10.1145/1228784.1228875

Citation Source

  • Scopus