Delay locked loop (DLL) employing pulse to digital converter (PDC) for calibration

Abstract

Aspects of the disclosure are directed to generating a quadrature clock signal from an in-phase clock signal. In accordance with one aspect, a delay locked loop (DLL), including a first pulse to digital converter (PDC) to generate a first pulse width measurement, wherein the first pulse width measurement includes a first sign and a first magnitude; a second pulse to digital converter (PDC) to generate a second pulse width measurement, wherein the second pulse width measurement includes a second sign and a second magnitude; a digital loop filter coupled to the first PDC and the second PDC, thedigital loop filter to generate a filtered comparison output based on the first pulse width measurement and the second pulse width measurement; and a first delay generation block to generate a quadrature clock signal based on the filtered comparison output and an in-phase clock signal.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to and benefit of U.S. Nonprovisional Patent Application No. 15 / 644,426 filed in the U.S. Patent and Trademark Office on July 7, 2017, which is hereby incorporated by reference in its entirety , and as fully set forth below and for all applicable purposes. technical field [0003] The present disclosure relates generally to the field of delay locked loops, and more particularly to delay locked loops for generating quadrature clock signals from in-phase clock signals. Background technique [0004] Several forms of converters can be used in electronic circuits to convert one signal in one domain to another signal in another domain. For example, a pulse-to-digital converter (PDC) is an electronic circuit that converts the width of a pulse (measured in units of time) into a digital representation. Different implementations of pulse-to-digital converters can be used in different applicati...

AI Technical Summary

Problems solved by technology

However, some pulse-to-digital converters (PDCs) can have a limited linear range and thus limit their practical application

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