I'm using the TPS2540A in a charging application for a Type A USB port where there's also a Type C port that can connect to a laptop. The devices needing charged could be any laptop, phone, tablet, etc that can charge from a USB Type A port.
There are two possible configurations for the TPS2540A that make sense: DCP (dedicated charger port) with auto-detect or CDP (charging downstream port). Our plan was to use CDP mode whenever the Type C is connected to a laptop to allow data connection between the laptop and the device plugged into the Type A port, otherwise use DCP mode. However, I'm uncertain about device compatibility in these two modes. It appears DCP auto-detect mode has more options than CDP mode, and thus would be able to charge more devices at the higher current.
Below are some questions that would help guide me to the ideal setting, relying on TI's experience with device compatibility and the various charge handshaking methods:
1) CDP mode supports BC1.2, and DCP supports BC1.2 DCP and divider mode. Is it a true statement that DCP will support maximum charging to more devices?
2) If switching from DCP to CDP mode on the TPS2540A with a device connected and possibly charging, will it properly renegotiate to use the maximum charging power for that mode? What about CDP to DCP mode?
3) Is the TPS2540A responsible for the CDP power negotiation or the host side USB port? What is the implication of staying in CDP mode when there's not a USB data connection to a host USB port?
Thanks,
Scott