TDP0604: TDP0604 Schematic Design review

Hello, we have received your case and the investigation will take some time. Thank you for your patience.

Hi Eddie, 

Below are my comments:
1. It looks like the devices are set to I2C mode. Why is the customer having pulldowns on SDA/SCL?

2. Based on the DDC connections, it looks like DDC buffer is disabled. However, the customer has HV_DDC connected. Was this for DDC snooping feature? If so, they have to connect to LV_DDC not HV_DDC since snooping is on LV_DDC side.

3. I noticed these nets appear on multiple pages:


Please ensure strap is available for all devices separately. 

4. 

These nets do not match in the third page.

5. Is the customer planning to use strap mode for some reason as it currently looks like they want to use i2c? If they are going to use i2c, they do not need to strap the control pins. I noticed that some pins had pullups and pulldowns like CTLEMAP_SEL. 

6. 
Please ensure CMC gives differential impedance of 100 ohm:


7. U93 is missing data connections:



Best,

Update SCH as below.

HDMI IN&OUT + DP to HDMI_A.pdf

1. It looks like the devices are set to I2C mode. Why is the customer having pulldowns on SDA/SCL?

[Eddie] Sorry, I have deleted the pull down resistors. Please kindly refer to the lastest SCH.

2. Based on the DDC connections, it looks like DDC buffer is disabled. However, the customer has HV_DDC connected. Was this for DDC snooping feature? If so, they have to connect to LV_DDC not HV_DDC since snooping is on LV_DDC side.

[Eddie] I have updated the SCH, please kindly refer to the lastest SCH.

6. 
Please ensure CMC gives differential impedance of 100 ohm:

[Eddie] Is it ok if I pick 90ohm CMC as default ?

7. U93 is missing data connections:

[Eddie] Thanks for the reminding. Please kindly refer to the lastest SCH.

CHEN HSUN HSUEH 说：

[Eddie] Is it ok if I pick 90ohm CMC as default ?

I checked on my end, and this should be fine. 

Below are my comments on the updated schematic:
1. For U8, I see that it has both level shifter and TDP0604 DDC connections:

If using level shifter, please disconnect on HV_DDC side. If using DDC snoop feature, please disconnect HV_DDC side and then connect LV_DDC side.

2. Is U13 taking DP++ signal? I noticed that it has decoupling capacitors on the RX side of the redriver. 

3. U93 is still missing some connections:

Hi Lydia,

Please see attached revised version.

HDMI IN&OUT + DP to HDMI_B.pdf

1. For U8, I see that it has both level shifter and TDP0604 DDC connections:

If using level shifter, please disconnect on HV_DDC side. If using DDC snoop feature, please disconnect HV_DDC side and then connect LV_DDC side.

[Eddie] Sorry, I have updated the sch again. Please see revised verison.

2. Is U13 taking DP++ signal? I noticed that it has decoupling capacitors on the RX side of the redriver.

[Eddie] U93 is appled for DP to HDMI ; U8 is applied for HDMI IN ; U13 is applied for HDMI OUT.

3. U93 is still missing some connections:

[Eddie] Sorry, I have updated the sch again. Please see revised verison.

Eddie

Hi, 

U93 is still missing a connection. 

Does U93 take DP signal, or DP++? Could you please confirm? Our part is not an active redriver so we will not be able to make DP signal into HDMI unless the input signal is DP++. 

Hi Lydia,

U93 is still missing a connection. 

[Eddie] Sorry, do you mean the HPD_OUT ?

Does U93 take DP signal, or DP++? Could you please confirm? Our part is not an active redriver so we will not be able to make DP signal into HDMI unless the input signal is DP++. 

[Eddie] The host output standard DP signal. If TDP0604 can not support DP , may I have your comments for other suitable part ?

Eddie