Hello,
We have designed some prototype / test boards using PTN5150A to control a USB alternate mode MUX using the EXT_SEL pin. When the PTN5150A is configured as UFP mode by the slide switch, everything works nicely as it should, the output of EXT_SEL changes with cable orientation and the MUX corrects for that. However when configured as DFP mode, EXT_SEL pin does not change with cable orientation, it is always high (LED D3 off). The tests were done by connecting two of these boards together, one configured as UFP and one as DFP.
Here is the relevant part of the schematic, the CC and VBUS lines connect directly to the USB-C receptacle, the 3.3V VDD is provided by a LDO connected to VBUS.
Is this intended behaviour? From the datasheet I would have thought that the EXT_SEL output should work at all times, and not be reliant on I2C operation. If not then what could my mistake or issue be?
Thank you
Whether use this PTN5150 as DFP connect with others UFP which no included the PTN5150,does this DFP PTN5150 EXT_SEL function good?
On the other connected board in UFP mode EXT_SEL correctly indicates cable orientation. I did some further testing and the CON_DET pin is low on the DFP configured board and high on the UFP configured board. So it is not an issue with the EXT_SEL signal itself, instead it seems to me that when connecting two PTN5150A the DFP configured one does not properly detect the connection.
Behaviour is the same when switching UFP/DFP roles between the two boards and also with different USB-C to USB-C cables, so I think it is unlikely that this is just a hardware fault on one board and more likely just logic that I do not yet quite understand.
Hi
When configured as DFP mode, EXT_SEL pin does not change, at this time what about EXT_SEL pin status of UFP?
Yes, same behavior no matter whether the UFP it is connected to is another PTN5150 or just a USB-C "2.0" connector with the appropriate 5.1k pulldowns on CC1/2.
It would be nice if someone could either confirm or rule out this being a hardware/silicon bug, maybe using OM13584 PTN5150A-PTN36043 evaluation board.