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:
Dec. 04, 2012
Filed:
Aug. 17, 2009
Gerrit Groenewold, Ramona, CA (US);
Gerrit Groenewold, Ramona, CA (US);
QUALCOMM, Incorporated, San Diego, CA (US);
Abstract
Short-circuit protection in switched output stages is described to protect switching output stages from excessive output current in short-circuit conditions which may cause device damage. Design techniques to attain this goal include measuring currents in switching transistors by placing a scaled transistor in parallel thereto, combined with circuitry for making drain voltages substantially equal. The various techniques for short-circuit protection comprise (a) using a transistor and an operational amplifier in combination, (b) using a single transistor in place of the operational amplifier, (c) using a circuit to generate over-current detection signals, (d) providing over-current detection signals to a driver in order to reduce the output current, (e) using an inverter to feedback regulate output current, (f) using a switch to bypass the current regulator during normal operation, and (g) automatically opening this switch in an over-current situation.