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. 14, 2006
Filed:
May. 17, 2004
Willem J. Kindt, Santa Clara, CA (US);
Gertjan V. Sprakelaar, Fremont, CA (US);
Willem J. Kindt, Santa Clara, CA (US);
Gertjan V. Sprakelaar, Fremont, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An input stage employs low-voltage MOSFETs as input devices for an operational amplifier circuit that operates at common mode voltages that may exceed the gate-oxide breakdown voltage of the input devices. Also, the input stage is arranged for relatively low noise. The input stage is arranged to detect the input common mode voltage and to feed back the detected input common mode voltage to a base of a bipolar folded cascode transistor that is coupled to the drain of the input devices. Accordingly, the input devices are bootstrapped such that they are protected from gate-oxide breakdown.