SN65DP159: Notebook, Desktop, All-in-Ones, Tablet, Gaming

Maria Fey

Prodigy 105 points

Part Number: SN65DP159
Other Parts Discussed in Thread: DP159RGZEVM, SN75DP159

Tool/software:

The DP159RGZEVM works only under DDC SCL_SRC and SDA _SRC configuration.

I tried I2C over AUX to DDC bridge follow all the requirements above and it did not work.

1.No pop R31, R32.

2. R127 removed.

3. Pop C2, C3.

4. I2C_EN Low.

5. Power from USB J13.

Please advise,

Thanks,

Maria Fey

11 months ago

+1 Vishesh Pithadiya 11 months ago

TI__Mastermind 40260 points

Hi Maria,

Are you using the DP++ functionality of the DP159, or are you going from HDMI to HDMI?

+1 Maria Fey 11 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Hi Vishesh,

We want a DP++ dual functionality of the SN65DP159RGZT , going from DP as a source to HDMI sink with I2C-over-AUX implementation. We need to replaced our obsoleted circuit; Part# MCDP2900A4T from Kinetic Technologies.

I start testing the evaluation board from TI, DP159RGZEVM and it works good only with my PC under I2C (SCL_SRC/SDA_SRC, R31/R32). The AUX link was disable (C2,C3 no pop).

Later I used a Pattern generator to test the Aux link with C2, C3 pop and R31, R32 no pop as well as R132, R133 and it did not work, no Video output.

0 Maria Fey 11 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

The chip that came with the Evaluation board that we purchased from TI is not the SN65DP159RGZT is the SN75DP159. (label over the IC).

Please advise.

Thanks,

Maria

0 Vishesh Pithadiya 11 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

The SN75DP159 is rated for lower temperature ranges. The functionality is the same.

I need more context on it working with the PC. Was just the I2C working or were you able to pass video through the device?

How are you using a pattern generator to test the AUX? are you sending the Manchester encoded commands? Without proper commands the link training will fail. Link training is required before video is sent.

Can you send a block diagram of your test?

+1 Maria Fey 11 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

The AUX doesn't work with our Pattern generator.

Ok, we will try the Link training before video is sent.

Thank you

+1 Vishesh Pithadiya 11 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

Upon further inspection of the MCDP2900A4T, you are looking to actively convert DisplayPort to HDMI. The DP159 does not support that, and we do not have any parts in our portfolio that does.

The DP159 converts DP++ to HDMI.

DP++ is AC coupled HDMI and the side band bus for DP++ is DDC if an HDMI sink is connected. This is why you are seeing issue with passing through AUX.

+1 Maria Fey 11 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Sorry, I was not very clear. For this project we just need only DP++ to HDMI and it works on my PC (Video OUT) when the I2C DDC lines (SDA_SRC/SDA_SRC) are populated. If I disconnect them and reconnect the AUX_SRCN/AUX_SRCP lines, NO Video output at all from both sources, PC or Pattern Generator.

0 Maria Fey 11 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Hi Vishesh,

The EVA board finally is working for us thanks to your help. Now I start working in our Schematic to use same circuit. I have a few questions:

1.The Jumper configuration pull-up/down 64.9K resistors can be replaced for 50K or 100K? We have a lot of the 100K.

2. The 5V (BOOST) regulator can be replaced for a P-channel Mosfet switch? We will use it only for pull ups for SCL/SDA SINK and BOARD_5V to HDMI TX connector.

3. We don't use CEC. Can we left open CEC_EN pin18 of the SN65DP IC?

0 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

1) Using 50k should be fine here

2) Can you provide a schematic snippet. Id like to double confirm before saying yes here.

3) CEC can be left floating. Its best to connect the CEC from the HDMI connector to the GPU if possible. Just bypass across. Its important to make sure the voltages are compatible though.

0 Maria Fey 10 months ago in reply to Maria Fey

Prodigy 105 points

0 Maria Fey 10 months ago in reply to Maria Fey

Prodigy 105 points

1.J190 is a customer Amphenol connector with their pinout.

2. U700 3.3V PWR supply have FSW connected to R854 and R853 not pop as well as TI EVA schematic. That is right?

+1 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

Thanks for the schematics! However, I'm struggling to zoom in to have a look. Are you able to send a PDF file?

Maria Fey said:
U700 3.3V PWR supply have FSW connected to R854 and R853 not pop as well as TI EVA schematic. That is right?

If thsi is following what we have designed in the EVM, then this will work. Ill be able to provide better guidance with a pdf schematic sorry:(

The schematic snippet I was looking for was the implementation with a P-channel Mosfet switch. Where would the 5V come from with this implementation? The outgoing HDMI signal will need HPD, SDA, and SCL all at 5V signaling.

+1 Maria Fey 10 months ago in reply to Maria Fey

Prodigy 105 points

Hi Vishesh,

We decided to use the same 5V Boost regulator as the EVA board and not the Mosfet, which is bad idea. Same with U700, it works good.

It is good to follow the masters (TI and team).

Thank you so much,

Maria

+1 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

sounds good

+1 Maria Fey 10 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Thank you for everything!

Maria

0 Maria Fey 10 months ago in reply to Maria Fey

Prodigy 105 points

Hi Vishesh,

I need your last input.

I removed from the board the following:

1. PWR net "BOARD_3P3V" and resistor R796, leaving only "VCC_3P3V" for the 3.3V output.

2. PWR net " BOARD_1P1V" and res R799, now only VDD_1P1V.

Attached see the Sch page related to this

New Schematic:

I also replaced the CMC chokes FL1-FL4 for R861-R868 for 802 Ohms 0201 res. The output HDMI lines are internally to a TMDS Switch

(TMDS442PNPR) and from the TMDS output to a Video card internal.

These changes were requested by our PCB layout Eng trying to save some space.

Please advise.

Thanks,

Maria

0 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

Are you able to send a pdf of the schematic?

Removing the resistor should be ok, but adding an 802 ohm resistor will be too much resistance on the main links. Is EMI a concern for thsi design? If so I recommend keeping the CMC on the circuit.

0 Maria Fey 10 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Hi Vishesh,

I sent you the Schematic 900656 Rev-D1.

The resistors are 8.2Ohms.

We used these chokes before with Kinetic IC, MCDP2900A4T and we had a lot of issues.

Thanks,

Maria

0 Maria Fey 10 months ago in reply to Maria Fey

Prodigy 105 points

The pdf. it did not go through.

You can send me an email and I will reply with the pdf attached.

Thanks,

Maria

0 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Sure,

Email is v-pithadiya@ti.com

0 Vishesh Pithadiya 10 months ago in reply to Vishesh Pithadiya

TI__Mastermind 40260 points

Hi Maria,

1) These resistor are too large on the main link HDMI outputs

2) I recommend having an option for pin-strap mode and I2C mode for easier debug.

3) The ESD clamping voltage is too high. I recommend suing a 3V-5V clamping voltage for our parts

The power supply looks ok.

0 Maria Fey 10 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Hi Vishesh,

Ok, I will remove the 8.2R resistors and pop R817 for pin-strap Low on I2C_EN/PIN.

Also replacing the ESD protection for lower voltage (3V-5V).

That is right?

Thank you,

Maria

0 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

No problem!

Yeah, please send the updated schematic afterwards so I can confirm.

Best,

Vishesh Pithadiya

0 Maria Fey 10 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Hi Vishesh,

I can't find same package (10-UFDFN) with lower clamping voltage.

Thanks,

Maria

0 Vishesh Pithadiya 10 months ago in reply to Maria Fey

TI__Mastermind 40260 points

Hi Maria,

Are you able to change the package. We recommend using the PUSB3FR4 as the ESD on the HDMI side.

0 Maria Fey 10 months ago in reply to Vishesh Pithadiya

Prodigy 105 points

Hi Vishesh,

The HDMI side (output OUT_D2P/D2N, etc.) not going externally they going to a TMDS switch internally. I want to use your part (PUSB3FR4) for the input side of the chip close to the connector J190, to replace D800 and D801.