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:
Jun. 25, 2002
Filed:
May. 23, 2001
Andrea Baschirotto, Tortona, IT;
Paolo Cusinato, Sestri Levante, IT;
Giampiero Montagna, Tortona, IT;
Rinaldo Castello, Arcore, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
A switched operational amplifier with fully differential topology, alternately switchable on and off, and a control circuit. The operational amplifier has a first differential output ( ) and a second differential output, and a control terminal. The control circuit includes a capacitive detecting network including a first capacitor and a second capacitor connected between the first and second differential outputs and a common-mode node, and a third capacitor connected between the common-mode node and ground in a first operative condition, and between the common-mode node and the supply voltage in a second operative condition. A control transistor is connected between the common-mode node and the control terminal of the operational amplifier and supplies a control current correlated to the voltage on the common-mode node. A switchable voltage source, connected to the common-mode node, supplies a desired voltage in a first operative condition, when the operational amplifier is off.