Output driver circuit with auto-equalization based on drive strength calibration
US9337807B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2014 |
| Grant date | May 10, 2016 |
| Priority date | — |
| Expiry date | Jan 24, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/018585
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Systems and methods for equalizing an output driver circuit based on information from calibration of the output impedance of the driver circuit are disclosed. Settings that result from the calibration are referred to as calibration codes. The output driver circuit includes multiple pull-up elements that are enabled or disabled to produce a desired output impedance when the output is high and multiple pull-down elements that are enabled or disabled to produce the desired output impedance when the output is low. The number of pull-up elements that are enabled and the number of pull-down elements that are enabled is set by calibration. The results of the calibration (i.e., the number of enabled elements for the pull-up and the number of enabled elements for the pull-down) are used to set controls for an amount of pre-emphasis and/or to set controls for output slew rates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.