Impedance matching and trimming apparatuses and methods using programmable resistance devices
US8222917B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2006 |
| Grant date | Jul 17, 2012 |
| Priority date | — |
| Expiry date | Nov 2, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H7/38
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Impedance matching and trimming apparatuses and methods using programmable resistance devices. According to one exemplary embodiment, the impedance matching circuit includes a programmable resistance element, a comparator, a resistor divider having a common node coupled to a first input of the comparator, and an impedance element control circuit coupled between an output of the comparator and the programmable resistance element. The programmable resistance element includes one or more programmable resistance devices (PRDs). Programmed resistances of the programmable resistance element combine with the resistance of an external reference resistor to provide an impedance matched termination. A change in the resistance of the termination impedance causes a change in the output of the comparator. The impedance element control circuit responds to changes in the output of the comparator by providing one or more program control output signals, which control the resistance values of one or more of the PRDs, thereby maintaining an impedance matched termination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.