Circuit and method for compensation if high-frequency signal loss on a transmission line
US6759868B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2001 |
| Grant date | Jul 6, 2004 |
| Priority date | — |
| Expiry date | Jul 24, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00384
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit and method that maintains the impedance matching characteristics of a common output driver while compensating for the high-frequency signal attenuation inherent in printed circuit board traces and other integrated circuit signal transmission media are disclosed. The circuit includes a pre-emphasis driver configured in parallel with a standard output driver. The pre-emphasis driver is a tri-statable device which mirrors a received logic input when in an “on” state and provides a high output impedance with no signal content when in an “off” state. The pre-emphasis driver is controlled by a pre-emphasis control signal configured such that the pre-emphasis driver can inject high-frequency signal components into a transmission line for a portion of a clock cycle. The pre-emphasis control signal is configured such that the pre-emphasis driver turns “on” in close approximation with data signal transitions and is turned “off” before a reflected signal caused by the impedance mismatch between the pre-emphasis driver and downstream elements (i.e., a transmission line and a receiver) appears at the parallel driver output. In its broade…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.