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:
Mar. 10, 2009
Filed:
Dec. 17, 2004
Matthew Felder, Austin, TX (US);
Russell A. Schultz, Austin, TX (US);
Matthew Felder, Austin, TX (US);
Russell A. Schultz, Austin, TX (US);
Sigmatel, Inc., Austin, TX (US);
Abstract
A semiconductor device includes an adjustable current source that is coupled to an external battery. The semiconductor device includes a feedback control module that is responsive to a voltage level at the external battery. The feedback control module also has an output that is directed to control the current supplied by the adjustable current source. Also, the feedback control module can selectively provide a signal to periodically and temporarily turn off the current supplied by the adjustable current source. A voltage at the external battery is measured during a time period when the current is turned on and during a time period when the current is turned off. While the current is turned off, the feedback control module can measure the external battery voltage so that it can be compared to the battery voltage while the adjustable current source is on.