Patent ID: 7276951
Filing Date: 2007-10-02
Classification: H03K,H03L

Abstract:
1. A delay circuit comprising: first and second delay elements, each having a propagation delay time T, wherein the first delay element propagates either an output signal from the second delay element or an output signal from a first mixing circuit to an output node, wherein the second delay element propagates an output signal from a second mixing circuit; and a control circuit to select the output signal from the second delay element or the output signal from the first mixing circuit to propagate through the first delay element, wherein each mixing circuit comprises; a first input to receive a first clock signal; a second input to receive a second clock signal, the second clock signal being a time delayed version of the first clock signal such that corresponding edge transitions of the first and second clock signals are separated by a time T; and an output to provide as the output signal from the mixing circuit a mixed clock signal that is a time delayed version of the first clock signal such that corresponding edge transitions of the first clock signal and the mixed clock signal are separated by a time selected from zero to T by providing a continuously variable time delay value to each of the mixing circuits.