Patent Number: 6,445,204

Title: Apparatus for probing digital signals within printed circuit boards

Abstract: In order to probe digital signals within a Printed Circuit Board (PCB) a sensor apparatus is implemented adjacent to a signal trace. The sensor apparatus receives crosstalk signalling from the signal trace and is coupled to a probing node capable of being probed by a test apparatus. Hence, in essence, the signal trace itself can be probed via the sensor apparatus and the probing node. The probing node can be implemented on the same layer of the PCB as its corresponding sensor apparatus or on a different layer that is more convenient for probing purposes. Further, the sensor apparatus could be implemented on the same layer within the PCB as its corresponding signal trace or alternatively could be implemented on an adjacent layer that still allows the sensor apparatus to receive crosstalk signalling from the signal trace. With the use of the sensor apparatus in combination with the probing node, it is possible to achieve accurate measurements of signals traversing the signal trace without significantly affecting the signal integrity of the signals traversing the signal trace. This is especially important in high speed designs.

Inventors: He; Jane J. (Ottawa, CA), Zhao; Liguo (Nepean, CA)

Assignee: Nortel Networks Limited

International Classification: G01R 31/28 (20060101); G01R 031/28 ()

Expiration Date: 09/03/2019