TUSB217-Q1: Does the TUSB217-A have an integrated CDP?

Hi Lauren,

I would recommend the TUSB217A-Q1 or TUSB216-Q1. The TUSB216 has an integrated CDP controller that can be enabled or disabled, while the TUSB217A-Q1 can choose between either a CDP or DCP.

Both these devices integrate a CDP controller, allowing these redrivers to communicate and configure a USB2 port. A CDP port should be able to provide 1.5A via VBUS, as is required in the BC1.2 spec.

Thanks,

Ryan

Hey Ryan, check my email for more context. 

The concern with TUSB217A is that it includes an integrated BC1.2 controller and that this function is enabled by default (is it?)

If it is, then my customer believes that a BC1.2-aware sink connected to the port may interpret the port as a CDP/DCP-capable charging port, and therefore may attempt to draw more current than a standard USB host port would normally allow.

The specific mismatch they are concerned about is this:

• • the port itself is intended to behave as a standard downstream port only
  • the port is limited to 900 mA for USB 3.2
  • but the USB 2.0 conditioner may still advertise CDP through its integrated BC1.2 controller

In that case, is it correct that a compliant sink could still attempt to draw up to the BC1.2 CDP current level (1.5 A), even though the port is only intended to support standard SDP current? In their application, they do not want to advertise a charging port. They want the port to behave only as a standard downstream port:

• • 900 mA max for USB 3.2 operation (i.e., The "standard" profile)

Regarding the TUSB217-Q1 (non-A), does this device also actively advertise a BC1.2 charging-port profile, or is it only BC1.2-compatible in the sense of passing USB 2.0 data correctly without forcing CDP/DCP advertisement?

Thanks,
Lauren

Hi Lauren,

Yeah, I just read it after sending that response, sorry about that.

Lauren Mayfield said:

The concern with TUSB217A is that it includes an integrated BC1.2 controller and that this function is enabled by default (is it?)

Correct, it is enabled by default. If the customer doesn't want/need BC1.2 support and SDP is okay, I would recommend using either the TUSB216 or the TUSB211A, both these parts either have the ability to not present as a CDP or do not have BC1.2 controller support.

Lauren Mayfield said:

Regarding the TUSB217-Q1 (non-A), does this device also actively advertise a BC1.2 charging-port profile, or is it only BC1.2-compatible in the sense of passing USB 2.0 data correctly without forcing CDP/DCP advertisement?

The TUSB217-Q1 does not support BC1.2 CDP functionality, so it will not force any CDP functionality. 

Is there any reason the customer is leaning towards the TUSB217-Q1 and not something like the TUSB216-Q1 or TUSB211A-Q1? Just curious, since I believe the TUSB216 and TUSB211A have a newer die compared to the TUSB217-Q1 which may improve performance slightly.

Regardless, enabling CDP functionality could cause a CDP BC1.2 connection to take place, so if that is not desired, I would recommend using a device that allows that functionality to be selected, like the TUSB216 or TUSB211A.

Thanks,

Ryan

Thanks Ryan!

They're fine to use TUSB216. Just to confirm, it could be TUSB216, TUSB216I, and TUSB216-Q1, or TUSB211A, or TUSB211A-Q1, those all allow for disabling the BC1.2 functionality? 

He needs second source options always so he's fine with qualifying a -Q1 as a second source.