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. 31, 1995
Filed:
Apr. 02, 1993
Donald M Archer, Sunnyvale, CA (US);
Jung S Hoei, San Jose, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An operational amplifier bias system provides input offset voltage trim current with minimum offset thermal drift. The bias system includes a bias generator that provides bias current to the op amp. Correction circuitry responsive to the bias current provides an input offset trim current that compensates for offset drift error with change in temperature. The correction circuitry includes a resistive element, an input current mirror responsive to the bias current for providing a reference current to the resistive element to provide a temperature coefficient conversion current having a predetermined temperature coefficient, and a voltage reference that sets the resistance of the resistive element.