An On-Chip Tunable Frequency Generator for Crystal-Less Low-Power WBAN Radio

作者：Shih Yi Chun^*; Otis Brian

来源：IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS, 2013, 60(4): 187-191.

DOI：10.1109/TCSII.2013.2251938

• Frequency lock loop (FLL)
• frequency reference
• frequency-to-voltage converter (FVC)
• ring oscillator (RO)
• switched capacitor
• wireless body area network (WBAN)

This brief presents a digitally tunable frequency generator for crystal-less low-power radios in size-constrained wireless-body-area-network applications. A switched-capacitor frequency-to-voltage converter is used to lock a ring oscillator (RO) to an on-chip reference voltage. The proposed frequency lock loop (FLL) significantly reduces the supply and temperature dependences of the RO frequency by 400x and 13x, respectively, to 0.23%/V and 126 ppm/degrees C compared to a RO without the FLL. The output frequency can be digitally tuned from 325 to 420 MHz with a resolution of 80 ppm to allow channelization or calibration.

• 出版日期2013-4