Differential wired communication link quality detector and differential wired communication link detection
| 645 - Abstract: |
| This invention relates to a LVDS receiver capable of detecting link failure, be it a single short failure, double short failure, single open failure, or double open failure. The invention proposes a method of determining this link failure in 3 steps using a peak detector, which is more noise resilient and a comparator only, instead of the common 3 comparators used in other market products. Moreover, the proposed solution is also characterized by providing a simplified and more compact design, with reduced overall costs and improved system reliability. |
Description
The fail-safe circuit presented here assesses the quality of the signal or potential link failure modes and provides a signal quality flag to take appropriate decisions when processing the received data. This is done with integrated circuits that monitor and measure incoming signal levels, amplitude, strength and impedances and then perform the appropriate control actions over the incoming and outgoing signals. The latter can range from blocking the incoming data stream to for example switching to the redundant communication link or enabling higher communication level protocol error detection and correction schemes. The link failures that can be detected with the proposed fail-safe circuits are:
a) single short failure: one input line short circuited to a fixed voltage
b) double short failure: both input lines are short circuited to a fixed voltage
c) single open failure: one input line has an broken connection (is disconnected). Both small and high capacitive loads at the input of the LVDS receiver are cases where the open failure should be detected.
d) double open failure: both input lines are disconnected, due to either a cable rupture between transmitter and receiver or due to the receiver line being connected to a switched-off transmitter, which is operating in cold redundancy.
Innovations and advantages:
The techniques commonly used in LVDS receivers are known to induce noise and self-oscillations to the data transmission that corrupt it and, for some applications, these are crucial factors. In order to minimize this effect and provide link failure detection, this invention proposes a new approach characterized by:
- Using a peak detector which is more noise resilient than the window comparator, used in other solutions.
- Only 1 comparator is needed instead of 3.
- Simplified design due to using fewer components and not requiring external hardware.
- Reduced dimensions and materials used.
- Reduced manufacturing costs.
- Improved reliability of the overall system.
Commercialisation aspects
Applications and Markets
This invention is useful for any application that uses LVDS, such as any electronic system that requires the communication between different parts (peripherals and a processor).
- Machine vision. This invention could be used to improve the signals received by machines to their vision systems, thus improving their perception of the environment and their autonomy.
- Other peripherals. Asides from vision and display peripherals, LVDSs are also used for interconnecting the processing unit to other peripherals, such as memory units. It could present strong benefits for applications on super-computers.
- Bio-medicine. Applications (such as DNA micro-array analysis, mass spectrometry and confocal microscopy, among others) where the data gathered is highly sensitive to noise, be it because of the low values or the precision required.
Intellectual property status
An international patent application has been filed.
