• State TI Thinks Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 644 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN75DP159: Redriver for HDMI that supports audio

Shifali N
Expert 2145 points
Part Number: SN75DP159
Other Parts Discussed in Thread: TDP158

Hi,

I am looking for a redriver/retimer for source side that can support HDMI 1.4 or lower also which has a capability to support audio through HDMI. Currently I have chosen TDP158 and SN75DP159. Can you please let me know which is the better option out of these two.

I have AC coupled HDMI source. Also can you please let me know whether these ICs support audio through HDMI

  • 0
    TI__Guru**** 177646 points

    Hi,

    One thing to keep in mind is that if the source checks the Adaptor ID Buffer to differentiate between HDMI and DVI output. The DP158 does not have a Adapter ID Buffer, and HDMI ID code will be read as 0x00h when Adapter ID Buffer is being read. HDMI ID code of 0x00h would indicate this to be a DVI interface, and audio is not supported over DVI. If switched to DP159, and when selected as HDMI, DP159 will have its Adapter ID buffer read as HDMI, and then audio will be supported.

    If the source does not check Adaptor ID buffer and will always output as HDMI with audio, then you can use DP158 as well.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Expert 2145 points

    Hi David,

    DP159 has two variant. SN75DP and SN65DP. Which one is the best choice for audio. Or whether both the variants can support audio.

    Also is there any specific points that I have to take care for audio circuit w.r.t schematics design.

  • 0 in reply to Shifali N
    TI__Guru**** 177646 points

    Hi,

    The difference between SN65 and SN75 is the operating temperature range. The SN65 ranges from -40 to 85C while the SN75 ranges from 0 to 85C. Both supports audio across the TMDS. 

    The audio, video, and auxiliary data are transmitted across the three TMDS data channels, so please follow the reference schematic in the datasheet or the EVM schematic for your design.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Expert 2145 points

    Hi David,

    I am using SN75DP159 in design. I am using hardware strap setting to configure IC. I was checking a reference design in datasheet and observed that 65K pullup and pulldown resistors are considered. 

    Is there any particular reason for considering that value. Or can I even consider 10K pullup and pulldown resistors

  • 0 in reply to Shifali N
    TI__Guru**** 177646 points

    Hi,

    For the pullup, you have to use 65k. For the pulldown, you can use 10k. Below is the tolerance. 

    [3-Level Input pins]
    Pull-up: 65k +/- 10%
    Pull-down: 0 to 65k + 10%

    [2-Level (LVCMOS) Input pins]
    Pull-up: 0 to 65k + 10%
    Pull-down: 0 to 65k + 10%

    keep the nominal resistor value + the tolerance within the ranges above.

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Expert 2145 points

    Hi David,

    Thanks for your response.

    I am using SN75DP159RGZT in my design. I have to support HDMI over audio as mentioned earlier. an you confirm that audio will be transmitted over TMDS lines and no need to connect SPDIF pin.

  • 0 in reply to Shifali N
    TI__Guru**** 177646 points

    Hi,

    SPDIF is a separate audio path from the audio transmitted across the TMDS data lanes. Does the source you are using supports a separate audio output?

    Thanks

    David