Patent · US Expired

I/O impedance controller

US6703908B1 · kind B1 · utility

5Cited by
36References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 20, 2000
Grant dateMar 9, 2004
Priority date
Expiry dateJul 20, 2020

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03H17/0054
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

There is disclosed apparatus and apparatus for impedance control to provide for controlling the impedance of a communication circuit using an all-digital impedance control circuit wherein one or more control bits are used to tune the output impedance. In one example embodiment, the impedance control circuit is fabricated using circuit components found in a standard macro library of a computer aided design system. According to another example embodiment, there is provided a control for an output driver on an integrated circuit (“IC”) device to provide for forming a resistor divider network with the output driver and a resistor off the IC device so that the divider network produces an output voltage, comparing the output voltage of the divider network with a reference voltage, and adjusting the output impedance of the output driver to attempt to match the output voltage of the divider network and the reference voltage. Also disclosed is over-sampling the divider network voltage, storing the results of the over sampling, repeating the over-sampling and storing, averaging the results of multiple over sampling operations, controlling the impedance with a plurality of bits fo…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.