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:
Aug. 28, 2018
Filed:
Sep. 13, 2017
Xilinx, Inc., San Jose, CA (US);
Sing-Keng Tan, San Jose, CA (US);
Xiaobao Wang, Cupertino, CA (US);
XILINX, INC., San Jose, CA (US);
Abstract
A transmitter includes: a driver circuit having a pull-up circuit, and a pull-down circuit, coupled to an output pad; a digitally controlled impedance (DCI) calibration circuit having a first reference driver, a second reference driver, and a reference resistor, the DCI calibration circuit configured to: generate a value for a first code by calibrating a first impedance in the first reference driver against the reference resistor; generate a value for a second code by calibrating a second impedance in the second reference driver against the first impedance; and adjust the value of the first code to match the first impedance with the second impedance; and a pre-driver circuit configured to supply the first code and the second code to the driver circuit for adjusting output impedance of the pull-up circuit and the pull-down circuit.