Digitally controlled impedance driver matching for wide voltage swings at input/output node and having programmable step size
US6909305B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2003 |
| Grant date | Jun 21, 2005 |
| Priority date | — |
| Expiry date | Aug 8, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/0005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digitally controlled impedance driver circuit including a number of fingers, some of which having FETs and series resistors sized in binary or other differential ratios, and some of the higher power FETs being sized in equal ratio and perhaps sharing a series resistor. A DCI controller circuit periodically determines a configuration of the DCI driver circuit that would result in the DCI driver circuit approximating a target impedance. Each time the DCI controller circuit does this, a comparator determines if the impedance of the DCI driver circuit should be increased or decreased. A noise attenuation circuit turns off (or on) only one of the high power fingers if the controller circuit determines that more (or less) impedance is needed even if turning off (or on) only one of the fingers would not result in the configuration of the DCI driver circuit determined by the controller circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.