Power down mode signaled by differential transmitter's high-Z state detected by receiver sensing same voltage on differential lines
US6593801B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 2002 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Jun 7, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A power-down signal is encoded into a differential pair of lines between two chips. When the differential transmitter powers down, it enters a high-impedance state and floats the differential lines A shunt resistor between a pair of differential lines equalize the voltages on the differential lines so they float to a same voltage when a differential transmitter is disabled and enters a high-impedance state. The condition of equal voltages on the differential lines is detected by an equal-voltage detector that generates a power-down signal when the differential lines are at equal voltages for a period of time. The period of time can be greater than the cross-over time during normal switching to prevent false power-downs during normal switching. Standard differential drivers can signal power-down using the high-impedance state, which is detected by equal voltages on the differential lines. A sensitive dual-differential amplifier and a simpler detector are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.