NSN is using 65LBC174A to convert TTL to RS485. And the output need to compatible with ITU-T V.11 standard.
All other test items are passed. Only one test failed.
It is “The resultant voltage due to imbalance (VE) shall not exceed 0.4 V peak-to-peak.” At page 10 of the standard.
The test environment is just as the figure showed.
The peak-to-peak voltage we test is 1.13V.
output drive RJ45 connector directly, and the layout is differential couple line, what can I do to decrease this imbalance voltage?