CYUSB4347 PD switcher required?

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Razor6412
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The EZ-USB HX3PD evaluation kit uses the NCP81239MNTXG to control the PD voltage delivered to the US and DS1 ports. Can this part be omitted such that 5VDC only is provided to the US and DS1 ports, and still be able to negotiate PD roles so that they US device can act as host while receiving power at 5VDC up to 3A? I want to make sure that eliminating this part and the higher voltage PD modes won't cause a problem with the PD role swap negotiations.

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Sananya_14
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750 replies posted 500 replies posted 250 solutions authored

Hello,

We dont have any reference designs for 5V only on the PD ports but based on the example project which was tested on another custom board, you could eliminate the PD related circuitry for the ports by routing the VBUS_P_CTRL_X and OCP_DET_X to the power switch for the respective port, leave VBUS_DISCHARGE_X unconnected. 

Best Regards,
Sananya

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Sananya_14
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750 replies posted 500 replies posted 250 solutions authored

Hello,

Yes, the US and DS1 NCP regulators can be removed on your board if you dont want a profile higher than 5V, 3A. However, the HX3PD firmware from the Dock SDK has the regulators enabled by default since it is based on the CY6611 schematic so would have to be modified to ensure that the PD negotiation completes successfully with your board.

Please refer to the attached HX3PD project that disables the US regulator I2C writes using the macro #US_5V_only that I have added in the PD controller project. You could use the *.hex files generated after building the project to SWD program the DMC and PD controller in your board.

Best Regards,
Sananya

Thank you!  Do you have any hardware reference design examples/schematics that show how the 5VDC should be routed to the USB ports that goes with this project?

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Sananya_14
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hello,

We dont have any reference designs for 5V only on the PD ports but based on the example project which was tested on another custom board, you could eliminate the PD related circuitry for the ports by routing the VBUS_P_CTRL_X and OCP_DET_X to the power switch for the respective port, leave VBUS_DISCHARGE_X unconnected. 

Best Regards,
Sananya