System and method for on-chip jitter and duty cycle measurement

Abstract

An apparatus for measuring time interval between two edges of a clock signal and includes an edge generator, a first multi-tap delay module, a second multi-tap delay module, and a multi-element phase detector. The edge generator produces a first edge at a first output node and a second selected edge at a second output node. First multi-tap delay module provides a first incremental delay at each tap to the first edge. Second multi-tap delay module provides a second incremental delay at each tap to the second selected edge. Each element of the multi-element phase detector has first and second input terminals. The first input terminal is coupled to a selected tap of the first multi-tap delay module and the second input terminal is coupled to a corresponding tap of the second multi-tap delay module. The output terminals of the multi-element phase detector provide the value of the time interval.