SLLA642 July 2024 TUSB564-Q1
To simulate a long cable DisplayPort system, two 4.6-meter DisplayPort cables are used in the signal path. One cable is placed before the TUSB564-Q1, and the second cable is placed after the TUSB564-Q1. The bench board adds additional loss with it's short pre and post-channel FR4 trace. A DisplayPort source is connected upstream, and measurements are taken at the end of the downstream DisplayPort cable.
For this test, a 5.4Gbps DisplayPort signal is used. The equalization on the TUSB564-Q1 is set to #9. This adds 11.0dB of gain on the DisplayPort lanes routing through the device. Following are the results of a 5.4Gbps DisplayPort compliance test taken at the downstream end of this system.
The compliance test is able to pass in this configuration with no issues. The eye diagram shows a defined eye opening and transition area. At 5.4Gbps, the TUSB564-Q1 has enough compensation to drive a DisplayPort signal through 9.2 meters of cable with margin to spare.