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:
Feb. 20, 2001
Filed:
Aug. 02, 1999
Daniel G. Prysby, Elk Grove Village, IL (US);
Brett Walter Chaveriat, Arlington Heights, IL (US);
Ronald Joseph Sullivan, Huntley, IL (US);
Ron Rotstein, Buffalo Grove, IL (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method and apparatus for compensating for input threshold variations in input buffers is provided. The method and apparatus compensate for input threshold variations by applying a bias voltage on a known capacitance of an RC calibration circuit using, for example, a pulse width modulator. The bias voltage helps ensure that the time to charge the known capacitance from the bias voltage to the input threshold voltage of the input buffer is independent of the threshold voltage. The bias voltage is chosen using an iterative process in which the time to charge from the bias voltage to the threshold voltage is compared with a reference time. The bias voltage is adjusted based on the comparison.