HD3SS3220: Automatic CC orientation detection and mux control

Jaakko Isohella

Part Number: HD3SS3220

From the spec I understood that the HD3SS3220 port controller should automatically detect USB-C cable orientation and control the mux according to that? On our board for some reason the mux control does not work, we have made the design to comply spec DFP example and have also routed I2C as a backup. Should the port controller work automatically (standalone) without any SW interaction?

over 6 years ago

0 Jaakko Isohella over 6 years ago

Intellectual 280 points

I checked that the CC lines are correctly pulled up but when plugging in USB-C cable with 5.1k pulldown the detection does not happen. Neither DIR is controlled or CABLE_DIR register is not updated.

0 Diego Cortes over 6 years ago in reply to Jaakko Isohella

TI__Mastermind 36085 points

Hello Jaakko,

Per your comments, I assume that the HD3SS3220 is in UFP mode, this mode requires the presence of VBUS to detect the connection. Please make sure that the DFP is turning ON VBUS.

The HD3SS3220 doesn't need extra SW configuration. You only have to configure the pins PORT, CURRENT_MODE, ENn_CC and ENn_MUX to the desired mode.

Regards,

0 Jaakko Isohella over 6 years ago in reply to Diego Cortes

Intellectual 280 points

It is in DFP mode. We connect 5V supply via 910kohm to VBUS_DET instead of gated VBUS. I took out the 910kohm resistor from the board and got the orientation detection working. Is there any reason to connect VBUS to VBUS_DET as the spec implies the VBUS detection is not enabled for DFP mode?

Is there be any risk if we leave the VBUS_DET floating on DFP mode?

0 Diego Cortes over 6 years ago in reply to Jaakko Isohella

TI__Mastermind 36085 points

The only Risk lies when there is a VBUS comming from the cable and you enable the board VBUS, this will connect both sources together.
Regards,
Diego.

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HD3SS3220: Automatic CC orientation detection and mux control