USB with over-voltage and short-circuit protection
US6946904B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 2002 |
| Grant date | Sep 20, 2005 |
| Priority date | — |
| Expiry date | Jun 17, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/085
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A transceiver circuit includes driver circuits, receiver circuits, and suspend-mode buffers that are arranged to withstand an over-voltage conditions that would otherwise damage those circuits. An over-voltage sense circuit is arranged to detect the over-voltage condition on a data line in the transceiver. Cascode devices are placed in critical points of the various circuits, while voltages are coupled to other critical points such that none of the transistor devices that are coupled to the data lines are damaged by the over-voltage condition. Selector circuits are arranged to couple the highest detected voltages to various transistor wells to prevent forward biasing parasitic diodes in the transistors. Series switching circuits are arranged to break critical conduction paths during the over-voltage condition. The over-voltage protection scheme is suitable for use in integrated USB transceivers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.