TPS25750: Enable output through GPIO

Hi Sebi, 

Sebastien Monn said:

The data will be provided by a USB 2.0 Hi Speed Hub which should also enable VBUS

I assume the USB2.0 Hub is on the same system as the PD controller (TPS25750). When you say enable VBUS, is there a device connected to the Type-C PD port? By default, our PD controllers will enable VBUS if a sink device is connected. There is no need to manually enable VBUS through GPIO. 

Sebastien Monn said:

My question is, is it possible to configure one GPIO as an enable input?

All the available GPIO events can be found in the Technical Reference Manual starting on page 37. Input GPIO events are labeled 'Input' under the I/O column. I'm not entirely sure what kind of 'enable input' you're looking for, can you provide further clarification on what is required? 

Sebastien Monn said:

The only configuration I've found was the Fault_Condition_Active_Low_Event.

This is an output active low GPIO event when overcurrent occurs on the Type-C port. In this system, is the PD trying to notify the USB 2.0 HUB or in some other orientation/flow? 

Thanks and Regards,

Raymond Lin

Raymond
Thank you for your response.

Raymond Lin said:

I assume the USB2.0 Hub is on the same system as the PD controller (TPS25750). When you say enable VBUS, is there a device connected to the Type-C PD port? By default, our PD controllers will enable VBUS if a sink device is connected. There is no need to manually enable VBUS through GPIO. 

Yes it's on the same system. The Hub has an fault input (overcurrent for example) and a power enable output, which is set when the Hub is ready to communicate with a device. It also disables the power switch of the USB port when an overcurrent event happens and turns it on again after 1s.

Raymond Lin said:

All the available GPIO events can be found in the Technical Reference Manual starting on page 37. Input GPIO events are labeled 'Input' under the I/O column. I'm not entirely sure what kind of 'enable input' you're looking for, can you provide further clarification on what is required? 

I've made a small block diagram to show our current idea:


We one GPIO of the PD will be used to switch the power advertisment between 900mA and 3A @5V. The other two are the signals from the hub. The power enable shall control the switch in the sense, that it only shall be enabled when the enable signal from the Hub is high and a sink is attached.

Raymond Lin said:

This is an output active low GPIO event when overcurrent occurs on the Type-C port. In this system, is the PD trying to notify the USB 2.0 HUB or in some other orientation/flow? 

Sorry, I meant the Fault_Input_Event. Could this be used as an enable signal?

Best regards,
Sebi

Hi Raymond

Raymond Lin said:

The PD controller (TPS25750) will handle all the power side of the USB Type-C port. In the event of an overcurrent TPS25750 will automatically disable the power path by opening the switch, this does not require an external control from the HUB to set. 

Ok if an Overcurrent Event happens, will it re-enable the power path after a certain time or is a I2C command necessary?

Raymond Lin said:

TPS25750 will automatically advertise the Type-C current of 3A upon a connection of a sink device. As mentioned in the previous statement above, the PD control automatically controls the switch (internal to the PD control) based on its state. The PD controller doesn't require external control to enable/disable the power path or start sourcing. 

Ok but the TPS25750 can use a GPIO to switch between both advertisments?

I'm also currently looking into the TP65988 (as we have dual USB-C). It seems to me, that it's quite similar to the TPS25750 and a GPIO can be used to limit the current to 5V @900mA. Is there any major difference from the point of view of functionality?

Best regards,

Sebi

Hi Raymond

Ok thank you for your support. We decided to go with the TPS65988 and order the evalboard for first tests.

Is it possible to get a schematic of the evalboard with higher resolution? The schematics in the user guide is blurred at some points.

Best regards,

Sebi

Hi Alex

Great, thank you for the schematics. This will help us when creating our design.
Also thank you, Raymond, for your support.

All the best,
Sebi