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:
May. 05, 2015
Filed:
Jun. 27, 2012
Hua Guan, San Diego, CA (US);
Eric B. Zeisel, San Diego, CA (US);
Qi Lou, Lake Forest, CA (US);
QUALCOMM Incorporated, San Diego, CA (US);
Abstract
A method and apparatus for current drain switching with a replica loop. The method comprises the steps of: matching a voltage across a current sense resistor with a voltage created by a reference current across a matched reference resistor; replicating an operating point of an output transistor using a scaled matched replica of the output transistor and the current sense resistor. The method then shifts a feedback voltage from the output sense resistor to the matched replica sensor and shifts the output of a gate from an output transistor to the replica transistor. A first switch is then actuated in order to preserve the gate charge of the output transistor. A second switch is actuated to sample and hold a drain voltage in the buffer in order to bias the drain of the replica transistor. A third switch is then activated to stop the output current.