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:
Mar. 16, 2004
Filed:
Oct. 22, 2002
Martin Reber, Zurich, CH;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
The invention relates to an operational amplifier comprising a first transistor amplifier stage at an input of the operational amplifier, which first transistor amplifier stage comprises chopped transistors, a second transistor amplifier stage cascoded to the first transistor amplifier stage, which second transistor amplifier stage is connected between the chopped first transistor amplifier stage and a supply voltage source, wherein the gain at the output of the chopped first transistor amplifier stage is reduced to g /g , where g *Rc is the gain of the first transistor amplifier stage, g *Rc is the gain of the second transistor amplifier stage and Rc is the resistance of the resistor between an output of the operational amplifier and the supply voltage source. An operational amplifier circuit comprises a main operational amplifier as specified above and feedback loops including capacitors between the inputs and outputs of the operational amplifier to form an integrator circuit or a filter circuit.