TUSB546-DCI: TUSB546I-DCI. Why did the SBU1/SBU2 need 2-M ohm resistor to GND is also recommended.

Xiaoxiang Liu

Expert 5175 points

Part Number: TUSB546-DCI

Hi Team,

Our customer is using TUSB546I-DCI.

And we have some questions：

1. Why did the SBU1/SBU2 need 2-M ohm resistor to GND is also recommended.

2.Do we have some configuration in the process of configuring Level 4 that will affect the IIC.

If the IIC cannot be used in a certain configuration, how does the chip control the communication on the side?

Thanks,

Xiaoxiang

over 2 years ago

0 David (ASIC) Liu over 2 years ago

TI__Guru**** 159871 points

Xiaoxiang

1. The 2MΩ pull-down resistors on SBU1 and SBU2 are representative of the leakage of ESD and EMI/RFI components including termination to ensure no floating nodes, and are intended to show compliance with zSBUTermination in USB Type-C r1.1.

2. Can you elaborate more on the 2nd question? In the GPIO mode, the pin configuration is sampled on power up, and TUSB546 has to be powered cycled again if pin configuration changes. In I2C mode, the change is on the fly without the need to power cycle.

Thanks

David

0 Xiaoxiang Liu over 2 years ago in reply to David (ASIC) Liu

TI__Expert 5175 points

Hi David,

1.Can we use other resistors besides 2M Ohm? What will be the impact?

2.I'll let the customer description be a bit more detailed.

Thanks,

Xiaoxiang

0 David (ASIC) Liu over 2 years ago in reply to Xiaoxiang Liu

TI__Guru**** 159871 points

Xiaoxiang

They need to make sure they do not violate the zSBUTermination spec as shown below.

Thanks

David

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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TUSB546-DCI: TUSB546I-DCI. Why did the SBU1/SBU2 need 2-M ohm resistor to GND is also recommended.