TUSB1046 AUX SBU issues

Hi,

The SBU/AUX looks correct in the schematic. Can you please take a multi-meter and measure the AUX/SBU common mode voltage in both the normal and flip orientation to make sure the common mode voltage meets the TUSB1064 requirement as shown below?

Thanks

David

When it's "working" AUX_P is at 3.1V and AUX_N is at 0V. This is weird as this looks incorrect per the spec sheet and how DP is designed to work. I can see AUX communication going by using my o-scope. If I flip the connector, but leave the FLIP line in the same state then AUX_P is at 0V and AUX_N is at 3V, which looks correct but AUX communication doesn't even try to start. Leaving the flip and connector the same if I swap the P/N on AUX to the PTN3460 then AUX communication is attempted but it looks like the PTN is not responding.

It only "works" when I swap the N/P lines for AUX to the PTN3460. It's really looking like something in the PTN3460 is not correct.

Also, I checked the TUSB1064 dev board when working the AUX_P is at 0V and AUX_N is at 3.1V which looks totally correct to me.

Hi,

If the AUX/SBU common mode voltage is not correct, then the AUX traffic should not pass through the TUSB1064 AUX/SBU switch. Are you measuring the AUX/SBU single-end or differential?

If you probe CC1/2 and FLIP, are you seeing the voltage on the FLIP pin follows the CC1/2 voltage?

Thanks

David

Signle-ended with DMM and o-scope.

Here are the voltages on FLIP, CC1, and CC2:

FLIP = 3.2V
CC1 = 0V
CC2 = 0V

Connector physically flipped
FLIP = 0V
CC1 = 2.8V
CC2 = 1.5V

Hi,

Below is the CC voltage values that a Source shall use to detect what is attached based on the USB Type-C Current advertisement (Default USB, 1.5A @ 5 V, or 3.0 A @ 5 V) that the Source is offering.

Which device are you using? It looks the device is not compliant to the USB Type-C spec.

Thanks

David

Cypress CCG6 (CYPD6125-40LQXIT) on the device side, and Cypress CCG3 on supplier side. The supplier side I'm used the CCG3 dev board (CY4531 EZ-PD CCG3 Evaluation Kit).

www.cypress.com/.../cy4531-ez-pd-ccg3-evaluation-kit

Hi,

Can you work with Cypress and make sure Cypress CCG3 is being properly configured as a DRP or DFP and CC6 is being configured as a DRP or UFP?

Thanks

David

Yes, I'll look into that. Just FYI, an off the shelf USB-C to DP / USB adapter works fine with the CCG3 dev kit board.

Hi,

Can you double check the CC1/2 voltage level with the working adapter and verify the voltage is meeting the spec requirement? If this is the case, then I will focus on the CCG6 configuration.

Thanks

David