10.1.1 Use Case of SNx5DP159

SNx5DP159 can be used on the motherboard and dongle applications. The following use case diagrams show the connection of AUX and DDC between source side and sink side. The control pin pull up and pull down resistors are shown from reference. If a high is needed only use the pull up. If a low is needed only use the pull down. If mid level is to be selected do not use either resistors and leave the pin floating/No connect. The 6.5-KΩ Vsadj resistor value shown is explained further in the compliance section, for the RSB package.

The DP159 was defined to work in mainly in source applications such as gaming systems, Blu-Ray DVD player, Desktop, Notebook or VR. The following sections provide design consideration for various types of applications.

Figure 30 shows the original connection of SNx5DP159 on motherboard through the DDC channel. The DDC DR default is 100-kHz and is capable to adjust to 400-kHz.

Figure 30. Implementation for Motherboard 1

Figure 31 shows the connection for both DDC and AUX GPU connections with the SNx5DP159RGZ. Only one can be implemented at a time. Only the RGZ package supports the I²C-over-AUX implementation. The control pin pull up and pull down resistors are shown for reference. If a high is needed only use the pull up. If a low is needed only use the pull down. If mid level is to be selected do not use either resistors and leave the pin floating/No connect.

Note 1: For applications where the GPU or Sink does not support clock stretching the DDC lines from the GPU/DP TX should bypass the SCL_SRC and SDA_SRC but still connect to the SCL_SNK and SDA_SNK pins on the DP159. The SCL_SRC and SDA_SRC pins must be pulled to ground. Note that if the GPU/DP TX cannot support the 5V DDC lines from the connector, a level shifter is needed to step down the 5V signals to the voltage level the GPU/DP TX can support.

Figure 31. Implementation for Motherboard 2

Figure 32 shows the SNx5DP159 in the dongle application. It uses the unified structure on DisplayPort connector. SNx5DP159 has to identify if the signal comes from DDC or from AUX in I²C-over-AUX format. Due to the AUX channel needed, use only the RGZ package for this application.

Figure 32. SNx5DP159 in Dongle Application