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:
Jan. 29, 2002
Filed:
Jun. 20, 2000
Oleksiy Zabroda, Kanata, CA;
STMicroelectronics, Inc., Carrollton, TX (US);
Abstract
A pair of equivalent controlled impedance buffers are connected in a push-pull configuration to a transformer primary coil. A pair of equivalent pre-drivers are connected to the pair of buffers. Each pre-driver receives a driver input signal and outputs a buffer input signal (based on the input signal) and a DC offset compensation signal. Each buffer receives the buffer input signal from its associated pre-driver for buffered output as a line driver signal to the primary coil. Each buffer further receives the DC offset compensation signal generated its pre-driver to compensate for an offset introduced by the transformer. A balanced bridge hybrid is also connected between the buffer output and internal nodes. An adjustment circuit processes the hybrid output during training mode to generate an adjustment signal for application to an adjustable current source within each buffer. By manipulating the adjustable current source with the adjustment signal, the output impedance of the buffer can be made to match the characteristic impedance of a transmission line connected to the transformer secondary coil.