Hi,
I am investigating on behalf of a customer the possibility for TPS25750 to additionally detect BC1.2 charging ports CDP, DCD, if the CC wires did not detect a USB-C or PD device as VBUS source.
The DP/DM lines also go to a FullSpeed (FS) hub in parallel to the TPS25750, on the same board.
The hub signals over its UFP to the USB-host as being a FS device by connecting a 1.5K PU on DP line to 3.3V when VBUS is present.
1) Can the DP/DM lines be shared by the FS hub (UFP) and the TPS25750 pins GPIO4/GPIO5 for BC1.2 detection, if PCB layout is done well?
2) Can the hub's 1.5K PU resistor be present on DP, and the TPS25750 still distinguish between CDP / DCD / no-charger (SDP)?
3) If the 1.5K cannot be there during BC1.2 detection, is there a signal (e.g GPIO) that TPS25750 use to signal "ongoing BC1.2 detection" to control the 1.5K PU resistor with?
4) We want to hold off enumeration of the hub until the TPS25750 has finished BC1.2 detection, so how long time does that detection sequence take for the TPS25750? The USB BC1.2 spec say that 'Tsvld_con_pwd' is about one second window before enumeration must start, as I read it.
Many thanks for clarifying these questions!
Br, M.A.M
