Design and Analysis of Actively-Deskewed Resonant Clock Networks

Active deskewing is an important technique for managing variability in clock distributions but introduces latency and power-supply-noise sensitivity into the resulting networks. In this paper, an adaptively deskewed resonant clock network, based on an injection-locked distributed differential oscillator, is described, in which the delay lines required for deskewing are incorporated into the injection-lock source, dramatically improving jitter immunity. A power management system based on automatic amplitude control of the resonant grid further enhances energy efficiency. A prototype system operates at a nominal 2-GHz frequency in a 0.18 mum technology with on-chip jitter and skew measurement circuits and with more than 25 pF/mm² of clock loading.