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:
Jan. 16, 1990
Filed:
Feb. 10, 1986
Ching-Lin Jiang, Dallas, TX (US);
William J Podkowa, Plano, TX (US);
Dallas Semiconductor Corporation, Dallas, TX (US);
Abstract
A delay circuit that can be implemented in a monolithic integrated circuit includes a plurality of capacitor/laser-fusible link series pairs. Delay of a binary output signal of the circuit with respect to an input transition is directly proportional to the amount of capacitance connected into the circuit. Because the laser-fusible links can selectively be opened with a laser, the amount of capacitance connected into the circuit can incrementally be reduced; thus, the delay of the circuit is reducibly adjustable to a desired value. By including a plurality of conductive element/laser-fusible link series pairs in the delay circuit, the delay of the circuit is also increasingly adjustable. A method for economically adjusting the delay of each of many like delay circuits embodied in a semiconductor wafer includes measuring a sample of the delays of the delay circuits, calculating an average delay, determining the difference between a desired delay and the average delay to determine an incremental amount of delay to eliminate or to add, determining from predetermined data which fusible links should be opened, and using a laser beam to open the appropriate links.