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:
Dec. 17, 2002
Filed:
Mar. 08, 1999
Masakazu Shoji, Warren, NJ (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
An operating parameter of an integrated circuit is made substantially insensitive to process variations by configuring the circuit such that an environmental parameter, e.g., supply voltage to a portion of the circuit, is made a function of one or more process parameters, e.g., conduction threshold voltages and mobilities in that portion of the circuit. In this manner, the effect of the process parameters on the circuit operating parameter may be partially or substantially offset by the effect of the process parameters on the environmental parameter. In an illustrative embodiment, the circuit operating parameter is an oscillation period of a ring oscillator. A voltage regulator generates a reference voltage which is determined at least in part based on known process parameter variations in the ring oscillator. The ring oscillator utilizes the reference voltage generated by the voltage regulator as its supply voltage, and its oscillation period is thereby made insensitive to the process parameter variations. In addition, back-bias effects may be introduced in the voltage regulator to compensate back-bias effects resulting from particular configurations of the ring oscillator. The design techniques of the invention may be applied to a wide variety of different types of integrated circuits, operating parameters, environmental parameters and process parameters.