Sara Johnson

US Patent:

20170023632, Jan 26, 2017

Filed:

Feb 1, 2016

Appl. No.:

15/012237

Inventors:

Darrell J. Johnson - La Mesa CA, US
John C. McCosh - San Diego CA, US
Sara Johnson - La Mesa CA, US

Assignee:

Psiber Data Systems, Inc. - San Diego CA

International Classification:

G01R 31/11
G01R 27/06
H03L 7/08
G01R 31/02

Abstract:

Briefly, a method and system is provided for testing a cable using a high performance Time Domain Reflectometry (TRD) system and method. The TDR has a timing generator that is constructed to generate a periodic launch pulse to excite a cable under test, and to generate sample signals that are time delayed from the launch pulse. The timing for the launch pulse and the sample signal may be defined by two correlated PLL circuits coupled to the same clock. In one implementation, the timing generator is constructed in a single FPGA. The invention also provides calibration circuitry to compensate for temperature, voltage, and manufacturing variations in the FPGA. In one example, a tester includes a switch system that enables one or more TDR engines to sequentially apply a TDR stimulus to substantially all the wire pairs in a cable harness, and to collect the resulting TDR waveforms. The waveforms are analyzed to determine if the cable harness meets quality standards.