Differential voltage controlled oscillator, and method therefor
AssigneeInternational Business Machines Corporation
InventorsJuan-Antonio Carballo, David William Boerstler, Jeffrey L. Burns, Ivan Vo
Life of this patent
Estimating the term…
Abstract
In a first form, a voltage controlled oscillator includes delay cells connected in a ring, and control elements connected to selectively bypass respective sets of the delay cells. The delay cells are operable to receive respective differential inputs and to generate inverted outputs. The control elements are operable to receive respective differential inputs and to generate non-inverted outputs with variable delays. The control element delays are variable responsive to respective differential control voltages.
Claims22
A voltage controlled oscillator comprising:
- delay cells operable to invert differential delay cell input signals;
- control elements operable to receive control element input signals and to responsively generate non-inverted output signals;
- connections for the delay cells to propagate the delay cell signals in a ring;
- and
- connections for the control elements to selectively bypass respective sets of the delay cells, wherein the control element delays have selectively variable delays, the delays being variable responsive to respective control voltages.
A voltage controlled oscillator comprising:
- delay cells connected in a ring, wherein such a delay cell comprises a first pair of series-connected transistors coupled in parallel with a second pair of series-connected transistors, with a gate of one of the transistors in the first pair cross coupled to an electrode of at least one of the transistors in the second pair, and a gate of one of the transistors in the second pair cross coupled to an electrode of at least one of the transistors in the first pair, and the delay cell is operable to receive differential inputs and generate differential outputs;
- and
- control elements connected to selectively bypass respective sets of the delay cells, wherein the control elements are non-inverting and are operable to receive respective differential inputs and outputs and to provide variable delays, the control element delays being variable responsive to respective differential control voltages.
A method for a voltage controlled oscillator comprising the steps of:
- a) propagating differential signals through delay cells connected in a ring, wherein the delay cells have respective differential inputs and outputs;
- b) selectively propagating a portion of the differential signals through control elements connected to selectively bypass respective sets of the delay cells and wherein the control elements have respective differential inputs and outputs and selectively variable delays;
- and
- c) varying the control element delays responsive to respective differential control voltages.
Dependencies are inferred from the claim text.