DP--AUX

硬件设计规则：

The upstream DP device must weakly pull down the AUX+ line to GND and weakly pull up the AUX- line to DP_PWR each with a resistor in the range 10kΩ to 105kΩ between the AC-coupling capacitor and the upstream device connector to assist detection of the upstream DP device and powered upstream DP device by the downstream device. A nominal 100kΩ resistor value
is recommended.（Source和Sink两端对AUX有上拉和下拉，应用中汽主要目的是维持驱动能力）
All downstream devices must have AC-coupling capacitors, regardless of whether they implement upstream DP device detection. The downstream devices must very weakly pull up AUX+ line and very weakly pull down AUX- line with 1MΩ (±5%) resistors between the downstream device connector and the AC-coupling capacitors. When AUX+ line DC voltage is L level, it means an upstream DP device is connected. When AUX- line DC voltage is H level, it means that a powered upstream DP device is connected.（耦合电容对AUX通道也非常重要，一般是0.1uF）

原文链接：https://blog.csdn.net/CSDN1013/article/details/106992157