TUSB321AI: Current detection issue

Vincent Chen64988

Part Number: TUSB321AI
Other Parts Discussed in Thread: TUSB321, TUSB211, TPS25910, TUSB542

Hi Team,

My customer would like to use TUSB321AI in his system as UFP port. He tested its function on TUSB524 EVM but the result is not as expected.

The EVM's type-C port was connected to a NB( HP zbook15g3) and NB's type-C port can support 5V/3A. Supposedly, both CC1 and CC2 should output low level but customer probed that the CC1 is at high level, CC2 is at low level.

https://pcase.pl/site_media/uploads/hp/ZBook15G3/HP-ZBook-15-G3.pdf

Customer removed U5(TPS25910), U6(TUSB211) out of the EVM, pull TUSB321 pin 4 to ground as UFP mode. Connecting VBUS_B and VBUS_C. Then probed OUT1/OUT2 signal level.

Ask customer to probe CC1/CC2/VBUS/OUT1 and CC1/CC2/OUT1/OUT2 waveform as following.

Could team help to comment why the result is not as expected? Any experiment we can do here?

Thanks a lot.

Vincent Chen

over 4 years ago

0 Brian Zhou over 4 years ago

TI__Guru** 119940 points

for UFP, CC1 high means CC1 is connected of DFP port.

0 Vincent Chen64988 over 4 years ago in reply to Brian Zhou

TI__Expert 4480 points

Hi Brian,

Sorry for some typo in my previous description.

Since TUSB321 is set to in UFP mode, both OUT1 and OUT2 should drive low level when attaching a 5V/3A type-C DFP port(HP NB). But what customer see is only OUT2 drives low but OUT1 keeps at high level, you can refer to waveform above. May I have you comment?

Thanks a lot.

Vincent Chen

0 Vincent Chen64988 over 4 years ago in reply to Vincent Chen64988

TI__Expert 4480 points

Hi Brian,

Due to customer's application is like dead battery mode, TUSB321 is un-powered before plug type-C cable. So, I suggested replace TUSB321 by TUSB321AI and do the same test. But the result is still not as expected. Please find below waveform.

The only different between TUSB321 and TUSB321AI is CC1 raises to about 1V.

VBUS power is established as cable is plugged and as CC1 raising, is that make sense? Supposedly, DFP supply VBUS power after CC communication, is it correct?

Customer's application is quite simple, customer's end equipment is UFP and by using TUSB321AI to get DFP's information to inform MCU DFP's power capability and sink power from DFP as well.

Do you have any comment about how customer can verify this function? Is there any other EVM is more suitable for customer to do the verification?

Thanks a lot.

Vincent Chen

0 Brian Zhou over 4 years ago in reply to Vincent Chen64988

TI__Guru** 119940 points

it seems OUT1/OUT2 only shows default current mode.

Can customer flip cable and see if CC2 goes high and CC1 goes low?

where do you get TUSB624 EVM, can you send full schematic?

0 Vincent Chen64988 over 4 years ago in reply to Brian Zhou

TI__Expert 4480 points

Hi Brian,

Below waveform shows the condition of flip cable to attach TUSB542 EVM. It is still strange.

I applied TUSB542 EVM that not only place TUSB542 but TUSB321, we only tested TUSB321 portion.

Can you comment how we modified this EVM is correct or not?

Thanks a lot.

Vincent

0 Brian Zhou over 4 years ago in reply to Vincent Chen64988

TI__Guru** 119940 points

from waveform it looks like CC1 is greater than 1.3V. It should be 3A. But OUT1/OUT2 shows default current. can you try TUSB321A?

0 Vincent Chen64988 over 4 years ago in reply to Brian Zhou

TI__Expert 4480 points

Hi Brain,

Thanks very much for your support. The issue is clarified, customer plugged to USB3.0 port of the NB and this port doesn't have capability to support 3A. He changed to thunderbolt port then TUSB321AI reacts and OUT1/OUT2 drive to low level.

Thanks a lot.

Vincent

0 Brian Zhou over 4 years ago in reply to Vincent Chen64988

TI__Guru** 119940 points

Great

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TUSB321AI: Current detection issue