TUSB216: Questions about datasheet

Hi Nison,

Naizeng Wang said:

What's the meaning of Host/Device agnostic in page 1?

Host/Device agnostic means that the device does not need to be setup in a certain orientation to face the host or the device. The TUSB216 will boost the signals that run underneath it, regardless of the direction and whether its going from host to device or device to host.

Naizeng Wang said:

• In page 1, TUSB216 can supports up to 10-m cable length with two TUSB216 devices. What's the topology look like? 
• Can you illustrate the daisy chain?

Please view this E2E FAQ for more information on a 10-meter setup, and how these devices daisy chain:https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1325293/faq-tusb216i-how-do-you-create-a-system-with-a-10-meter-passive-cable-using-a-usb2-redriver

We recommend implementing daisy-chained redrivers in longer systems, or in systems with extreme loss.

Naizeng Wang said:

What's end eye compliance?

Sorry, this is meant to just be near-end eye compliance. A near-end eye diagram is an eye diagram measured at the host as it comes out of the connector and heads towards the device.

Naizeng Wang said:

Should the power supply of I2C be earlier than VCC of TUSB216?

If using I2C, yes, it would need to be powered up with the I2C pins pulled up before the TUSB216 is powered-up.

Naizeng Wang said:

Boost can only improve eye width and RX sensitivity can only improve both eye width and eye height. Correct? Why?

Boost is able to control the VHigh and VLow margins of the eye diagram using DC Boost (Eye height), and is able to increase the rising/falling edge timing margins of the eye diagram by using AC Boost (Eye width). RX Sensitivity is used primarily to improve the levels of VHigh and VLow at longer cable lengths as well as improve ISI jitter, as both these things can be introduced at these longer cable lengths.

Naizeng Wang said:

Could you please explain more about this test?

I believe you sent the incorrect picture, I am not sure which test you are referring to.

Naizeng Wang said:

• Could you please explain more about this?
• 

The TUSB216 utilizes a finite-state machine for controlling what level is set for RX_SEN and BOOST, as well as when it is enabled. By setting the CFG_ACTIVE bit, the FSM is halted which stops the redriver. After this bit is unset, the FSM is reset to update to any changes made, and the redriver is reenabled.

Naizeng Wang said:

• Could you please explain more about this?
• 

The TUSB216 comes with a CDP controller for CDP advertisement, helping with high-power charging negotiation for USB BC 1.2.

Naizeng Wang said:

• Could you please explain more about this?
• 

This is just saying that when design the schematic/layout of a board utilizing our redriver, it is better to keep the pads necessary for the pull-ups/pull-downs associated with the RX_SEN and BOOST pins, that way if the settings of these pins need to be changed, they can be without requiring a full board rework.

Naizeng Wang said:

Could you please share the diagram of below placement? 

This diagram describes which section of a signal is pre-channel and which is post-channel for a host to receptacle application:

The TUSB216 can support either a 4 meter pre-channel or a 5-meter post-channel. It can also support a combination of pre/post-channel within the 5 meter range. It cannot support a 4 meter pre-channel AND a 5 meter post-channel.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1325293/faq-tusb216i-how-do-you-create-a-system-with-a-10-meter-passive-cable-using-a-usb2-redriver

This FAQ should still cover cascading/daisy-chaining TUSB216s.

If you would like to setup a call, I should be available to help field any questions or any clarifications, though we can also keep this to E2E if these answers are sufficient, as its easier to provide materials this way.

Thanks,

Ryan