Question Regarding unused pins and downstream ports on CYUSB3333

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Anonymous
Not applicable
Hello!

My team and I are designing a device that uses the CYUSB3333 to implement a USB hub; the upstream port will be a USB 3.1 Type C connector, and on the downstream side we will have two USB 3.0 Type Micro B connectors, as well as a microcontroller connected directly on the board using USB 2.0. I had a few concerns I wanted to go over regarding this specific chip:

-What is the preferred method to connect the Type-C connector data pairs to the Hub IC? In the reference design the signals are sent through a Mux that allows for video to be sent to a display port, but we are strictly using the USB data only. The connector has 4 USB 3.0 Pairs, but the CYUSB3333 only has pins for two of the pairs.

-How should the unused PD Controller Port 2 pins be connected? Should they be left floating, or connected to a voltage source?

-How should the I2C, Debug, and GPIO pins be connected if they will also be unused?

Thank you!

Regards,
Simran
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1 Solution
Anonymous
Not applicable

Hi Simran,

Since your application needs only data transfer on the upstream port, you can short the two pairs of TX lines and two pairs of RX lines together to form a single pair of TX and RX each so that the Type-C connector can be can be connected in any orientation.

You can pull the I2C lines up to 3.3V through proper resistors (2K - 10K).

You can leave the other pins unconnected.

Regards,

Anil

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1 Reply
Anonymous
Not applicable

Hi Simran,

Since your application needs only data transfer on the upstream port, you can short the two pairs of TX lines and two pairs of RX lines together to form a single pair of TX and RX each so that the Type-C connector can be can be connected in any orientation.

You can pull the I2C lines up to 3.3V through proper resistors (2K - 10K).

You can leave the other pins unconnected.

Regards,

Anil

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