Patent Number: 6,396,358

Title: Dual-control ring voltage controlled oscillator

Abstract: A circuit of a dual control voltage-controlled ring oscillator is disclosed having significantly less power and area while still maintaining a large frequency range and tune accuracy. The dual control ring oscillator has at least two delay paths which can be added or interpolated according to an interpolation variable set by a coarse tune and a fine tune code. In addition, moreover, each of the delay paths have a number of variable delay elements which are varied in response to another input code. When the variable delay elements are capacitors, the capacitance will be varied in accordance with another coarse tune code. In the preferred embodiment, the input codes are digital and the frequency range obtained can be greater than two to one. First, the variable delay elements are adjusted to obtain coarse tuning of the dual control ring oscillator then the interpolation variable is more finely adjusted to obtain fine tuning of the ring oscillator. Phase control can be similarly accomplished using coarse tuning by adjusting the delay of the paths, and then using fine tuning to interpolate the delay paths.

Inventors: Poss; Joey Martin (Rochester, MN), Reynolds; Scott Kevin (Granite Springs, NY)

Assignee: International Business Machines Corporation

International Classification: H03K 5/13 (20060101); H03L 7/099 (20060101); H03L 7/08 (20060101); H03K 3/00 (20060101); H03K 3/03 (20060101); H03K 5/00 (20060101); H03B 005/24 ()

Expiration Date: 05/28/2019