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. 27, 2016
Filed:
May. 07, 2015
Linear Technology Corporation, Milpitas, CA (US);
Amitkumar P. Patel, San Jose, CA (US);
Carl Nelson, San Jose, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
In an LDO regulator, two feedback loops are created. The first feedback loop includes a high power PNP bipolar power transistor connected in series between the input voltage Vin terminal and the output voltage Vout terminal. The first feedback loop includes a first error amplifier that controls a drive transistor to drive the base of the power transistor such that Vout matches a set voltage Vset. This first feedback loop circuitry uses an operating voltage (the upper rail voltage) that is regulated by a second feedback loop and is approximately 300 mV greater than Vout. As a result, the control circuitry will be powered by a low ripple supply to improve output PSRR. Further, the power transistor is connected such that any noise in the input voltage is a common mode voltage across the base-emitter of the transistor.