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:
Sep. 14, 2010
Filed:
Dec. 30, 2008
Yat to William Wong, Hong Kong, HK;
Chik Wai David NG, Hong Kong, HK;
Ho Ming Karen Wan, Hong Kong, HK;
Kam Chuen Wan, Hong Kong, HK;
Kwok Kuen David Kwong, Davis, CA (US);
Yat To William Wong, Hong Kong, HK;
Chik Wai David Ng, Hong Kong, HK;
Ho Ming Karen Wan, Hong Kong, HK;
Kam Chuen Wan, Hong Kong, HK;
Kwok Kuen David Kwong, Davis, CA (US);
Abstract
An error amplifier can be used to control a power regulator transistor. The error amplifier has a main amplifier, a pull-up auxiliary amplifier, and a pull-down auxiliary amplifier that all drive an output. A compensating capacitor on the output sets a single dominant pole for all amplifiers, increasing stability. High slew rates are provided by increased slew current from the auxiliary amplifiers that turn on when the differential input has an absolute voltage difference larger than an intentional offset. The intentional offset is introduced into the auxiliary amplifiers by adjusting a p-channel to n-channel transistor ratio in a leg of the auxiliary amplifiers. A source degenerated resistor in the main amplifier reduces supply headroom and increases linearity by connecting sources of two differential transistors that receive the differential input. Cascode transistors increase gain and output impedance. Reliability is increased as no positive feedback is used in the amplifiers.