Systems and methods for detecting terminal state and setting output driver impedance
US7696778B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2009 |
| Grant date | Apr 13, 2010 |
| Priority date | — |
| Expiry date | Jan 16, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/0005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Embodiments of the present invention include systems for calibrating an output circuit. A comparator is coupled to a calibration terminal and configured to determine whether the calibration terminal is in a first state coupled to a calibration resistor or in a second state. A calibration circuit is coupled to the calibration terminal and configured to generate a calibration value based in part on the presence or absence of the calibration resistor. An impedance selector is coupled to the calibration circuit, the comparator, and a default calibration value. The impedance selector is configured to select the default calibration value when the comparator indicates the calibration terminal is in the second state and to select the calibration value coupled from the calibration circuit when the comparator indicates the calibration terminal is in the first state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.