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:
Jul. 13, 1999
Filed:
Jul. 31, 1997
Brian J Arkin, Pleasanton, CA (US);
Credence Systems Corporation, Fremont, CA (US);
Abstract
A delay line formed by a set of series-connected logic gates produces a sequence of output pulses in delayed response to a sequence of input pulses. The delay provided by a delay line changes with the frequency of its input pulse sequence because of temperature change in the gates due to changing power usage. Therefore a pulse stuffing circuit is provided to monitor the sequence of input pulses supplied to the delay line and to generate one or more stuff pulses when a period between successive input pulses exceeds a target maximum period. Each stuff pulse is sent as an additional input pulse to the delay circuit to decrease the period between input signal pulses. Although the delay circuit adds extra pulses to its output pulse sequence in response to the stuff pulses, the pulse stuffing circuit includes a gating circuit for removing those extra pulses from the output pulse sequence.