Impedance matching commonly and independently
US7196540B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 9, 2004 |
| Grant date | Mar 27, 2007 |
| Priority date | — |
| Expiry date | Jan 16, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/028
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A semiconductor device is easy for high accuracy impedance matching against differences in impedance of a transmission line and a package wire. A semiconductor chip having external output buffers and a packaging circuit are included. Each external output buffer has a first output portion whose internal impedance is adjusted commonly with other external output buffers in accordance with impedance control data and a second output portion whose internal impedance is adjusted independently of other external output buffers. Both of the first and second output portions are connected in parallel to a common output terminal. Common adjustment by the first output portion can cope with impedance of the transmission line and individual adjustment by the second output portion can cope with a difference of package wires.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.