TUSB1064: TUSB1064

Hugo Liu

Part Number: TUSB1064
Other Parts Discussed in Thread: HD3SS460,

Hi Sir,

Our customer used the TUSB1064EVM with Dell XPS15 9550, But no DP Alt mode output.

The DA400.Zip file is used DPA-400 read data, 20190103-source.bin.html is MUX side, 20190103-sink.bin.html is after MUX.

The Good NB Waveform.Zip File is used other NB waveform, But Dell XPS15 9550 no waveform.

Could you give us a suggestion?

Hugo

DA400.zip Good NB Waveform.zip

over 5 years ago

0 David (ASIC) Liu over 5 years ago

TI__Guru*** 139515 points

Hugo

Please use a multi-meter and check the common mode voltage on AUXP and AUXN. AUXP common mode voltage needs to be between 0 and 0.4V and AUXN common mode voltage needs to be between 2.7 and 3.6V.

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

If by pass TUSB1064 the AUX function is ok, we are use jump.
for DELL NB have other TI Device to choose? we need Adjustment DELL AUX voltage level?

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

I am suspect the SBU/AUX common mode voltage is not correct, please measure the common mode voltage on AUXP and AUXN. Common mode voltage is achieve by the pullup/pulldown resistor on AUXP/AUXN. There should be 100k pulldown on the source NB side and 1M pullup on the TUSB1064 side for AUXP, gives you 0.3V common mode voltage on AUXP. There should be 100k pullup on the source NB side and 1M pulldown on the TUSB1064 side for AUXN, gives you 3V common mode voltage. Common mode voltage must be correct in order for the communication to pass through the SBU/AUX switch.

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

Our customer is used they are Product & TI EVM verify this issue, But this issue is following Dell XPS15 9550. other NB is Good.
in Dell XPS15 9550 no AUX Signal, So no input & output waveform on AUX/SBU pin.
This issue only on Dell XPS15 9550 be found.

They are old product used the HD3SS460 with DELL XPS15 9550 is function OK.

Test Pass NB, DELL XPS13 9350/9360/9370, Lenovo X1, Apple MAC 2016/2017.

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

HD3SS460 does not check AUX common mode voltage, TUSB1064 does. Please check the common mode voltage on AUXP/AUXN, I am suspecting the AUXP/AUXN common mode voltage is out of spec with Dell XPS15 9550.

You can also try to have AUXP pull low through 1M resistor and AUXN pull high through 1M resistor.

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

Our customer used multi-meter check the common mode voltage on AUXP and AUXN as below.

Is this out of spec?

AUXP(SBU1)=1.743V
AUXN(SBU2)=53.6mV
MUX_AUXP(Pin26)=1.74V
MUX_AUXN(Pin27)=55.5mV

Hugp

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

This verifies that the common mode voltage is not correct and therefore SBU/AUX communication will not go through the TUSB1064. Common mode voltage for AUXP needs to be 0 to 0.4V and common mode voltage on AUXN needs to be 2.7 to 3.6V. Can you please try to have 1M pulldown on AUXP, 1M pullup on AUXN, and re-check the voltage?

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

Confirmed customer, they are have used the 1M pulldown on AUXP , 1M pullup on AUXN.

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

To clarify, when they did measurement
AUXP(SBU1)=1.743V
AUXN(SBU2)=53.6mV
MUX_AUXP(Pin26)=1.74V
MUX_AUXN(Pin27)=55.5mV

Do they have 1M pulldown on AUXP and 1M pullup on AUXN?

The correct implementation is 1M pullup on AUXP and 1M pulldown on AUXN.

Please share the schematic so that we are all on the same page.

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Dear David,

we are use the DELL P2415Q monitor to verify the TUSB1064RNQEVM,

the DELL XPS13 7390 & HP SPECTRE can be show the picture to monitor.

But XPS15 9550 still not Picture on Monitor.

we had rework TUSB1064RNQEVM 1M on R12 & R13.

	NB	AUXP	AUXN	SBU1	SBU2
DELL	XPS15 9550	2.964	0.0056	1.7	0.023
DELL	XPS13 7390	0.743	2.364	0.742	2.363
HP	SPECTRE	0.716	2.324	0.717	2.324

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

This is an issue with the XP15 9550, the strong 100k pulldown on AUXP is incorrect or missing, and 100k pulldown on AUXN is incorrect or missing in XPS15, resulting in incorrect common mode voltage for TUSB1064.

On the TUSB1064EVM, please have 100k pulldown on AUXP and 100k pullup on AUXN. What is the voltage after you do the rework and does the monitor work now?

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

Thank for your suggest.
How about 1M resistance, Remove it or 100k & 1M Both on EVM?

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

Please remove the 1M.

Thanks

David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

Good news, our used the 100k pulldown on AUXP and 100k pullup on AUXN.
The function is ok, but the TI Datasheet is show the 1M resistance value,
If our customer change to 100k , then any rick?
Do you have document to Description 100k?

AUXP=2.5V
AUXN=0.5V

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

Below is an AUX channel block diagram.

On the AUXP, we have 100k pulldown on the source side and 1M pullup on the sink side, results in ~0.3V common mode voltage on AUXP.

On the AUXN, we have 100k pullup on the source side and 1M pulldown on the sink side, results in ~3V common mode voltage on AUXN.

The 1M resistor in TUSB1064 assumes we are dealing with a DP compliant source.

Looking at the previous common mode voltage measurement results, it looks like we are dealing with a non-compliant DP source . The 100k pullup/pulldown on the source side is missing or populated with resistor weaker than 1M resistor.

By adding 100k on AUXP/AUX on TUSB1064, we basically make the 100k resistors to be the strong resistor when comparing against 1M resistor, therefore correctly set the common mode voltage for both AUXP and AUXN.

On a compliant DP system, we would have two 100k pulldown/pullup, the two combined 100k pulldown (50k) would still be strong when comparing against 1M resistor. AUXP common mode voltage would be around ~0.157V and AUX common mode voltage would be around ~3.143V, still within AUXP/N common mode spec requirement. It looks the latest measurement is backward, would you please check again?

Again, the 100k is a workaround solution for non-DP compliant system. The fix needs to be on the source side to make it to be compliant.

Thanks

David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

The TI TUSB1064EVM only have TYPE C & DP connector,
How to verify non-DP compliant system?

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

What other interface do they plan to use?

Thanks
David

0 Hugo Liu over 5 years ago in reply to David (ASIC) Liu

Genius 5095 points

Hi David,

Our customer this design is the TYPE C to DP Docking.

Hugo

0 David (ASIC) Liu over 5 years ago in reply to Hugo Liu

TI__Guru*** 139515 points

Hugo

Would you please provide more detail on the customer's implementation? Are they looking to connect non-DP compliant to the dock? I am trying to understand what they to accomplish here.

Thanks
David

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TUSB1064: TUSB1064