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. 15, 2009
Filed:
Sep. 24, 2007
David Sobel, Oakland, CA (US);
Augustine Kuo, Berkeley, CA (US);
David Sobel, Oakland, CA (US);
Augustine Kuo, Berkeley, CA (US);
Broadcom Corporation, Irvine, CA (US);
Abstract
A low-noise transmitter architecture and method for high linearity, high output-swing systems such as Asymmetrical Digital Subscriber Line (ADSL) systems. The transmitter uses a switched-current DAC having a current source coupled to ground, followed by a current-to-voltage converter. The resistance of the current source is typically large enough so that noise from an op-amp included in the current-to-voltage converter is not significantly amplified at the output. The current source may be passive and may include at least one resistor connected to ground. With a passive current source, portions of a signal output by the DAC enter either the current source or the current-to-voltage converter, but not both, eliminating noise in the system produced by the current source.