TUSB1044: Schematic checking and problem solving

Hi,

Do you have a block diagram that you can share? Also, do you have a version of PDF which I can search the net name?

Where does the TUSB1044 input comes from? 

Also, the TUSB1044 AUXP/N implementation does not look right. Why do you have multiple AC coupling caps and pullup/pulldown on them?

Thanks

David

Hi David,

I'm sorry, because the company's security measures can't provide a version of PDF, can only provide pictures for reference.

I re-uploaded a schematic reference design, which includes the system block diagram and the revised implementation of the TUSB1044 AUXP/N

Thanks

Lillo
TUSB1044-RD.pdf

Lillo

Is this a DP sink or a DP source application?

Can you please replace C0808 and C0821 with zero ohm resistor?

How is the hot plug being connected? 

Thanks

David

Hi David,

The DP receptacle is the unisoc uis7885 chip as output, external screen display.
It can be replaced with zero ohm resistor.After replacement, the phenomenon remains the same. No output is displayed on the connected DP screen
Hot  plug connects one of the GPIO pins of the UIS7885.

Thanks 

Lillo

Lillo

1. Can you change I2C_EN to floating? This will disable TUSB1044 AUX snooping and enable all four DP lanes

2. For the AUX channel, can you please have UIS7885 AUX connected directly to the DP receptacle as shown below?

Thanks

David

David,

1.Changed  I2C_EN to floating as described above and  the AUX channel is connected according to the picture above,the phenomenon remains the same. No output is displayed on the connected DP screen.

Thanks 

Lillo

Lillo

Can you please confirm that SS2_RX is lane 0 and SS2_TX is lane 1?

Also, for the AUX connection, can you please check to see if this is correct?

Is HPDIN high at 3.3V?

With the above modification, can you set FLIP pin to 0, CTL0 = 0, and CTL1 = 1 and see if Display works?

Thanks

David