The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 2009
Filed:
Jun. 17, 2005
Robert Callaghan Taft, Munich, DE;
Christopher Alan Menkus, Munich, DE;
Robert Callaghan Taft, Munich, DE;
Christopher Alan Menkus, Munich, DE;
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A clock receiver for an integrated circuit includes duty-cycle correction capabilities based on monitoring an average value associated with an internally generated clock signal. An active adjustment circuit within the clock receiver provides correction to each leg of the differential clock signal based on two correction signals. The correction signals are derived from a comparison of the average value associated with the internal clock signal with a target voltage. The target voltage is based on a trip-point of an inverter stage in a logic stage that is driven by the internal clock signal. The closed loop control of the correction signals adjusts the average value of the internal clock signal until it is substantially equal to the target voltage. By straddling the internal clock signal about the trip-point of the inverter stage, the duty-cycle associated with the internal clock signal is adjusted to substantially a 50% duty cycle.