Other Parts Discussed in Thread: TPS25741
I have the EVM configured for 65W with a 24v supply and connected to a device that will charge with 5v and 20v profiles only.
According to the data analyser that I am using, if the /EN12v link is fitted (Don't advertise 12v) the EVM advertises 5v and 20v as expected and the connected device charges normally at 20v.
If I remove the link so that 12v is advertised, the EVM offers 5v, 12v and 20v as expected and the connected device requests 20v which is all as expected. But the EVM does not active the GDPG line to turn on the 20v to the bus even though the 20v rail has come up. So both CTL2 and 1 have gone low. Also, because GDPG does not turn on the 20v to the bus, the TPS25741 does not send the PS_RDY message to the device which causes the device to send a hard reset to the EVM. This scenario now cycles indefinitely.
Any idea why GPDG would not activate the FET when 12v is enabled but not being requested.
Help please
Trevor Emerson