Other Parts Discussed in Thread: TPS55288, TPS65981
Hello,
I am using TPS65982 to control charging modes for a USB-C device. This chip is new to me and I am currently going through the learning curve to make it operational. The Application Customization Tool GUI is being used to create a .bin file to program a flash chip (W25Q80) with SPI. I am able to get USB-C device charging at about 1.1A at 5V or 500mA at 12V but I cannot get a cable connection detected. The board is powered with 5V(VIN_Z = PP_EXT). PP_HV under normal operations should be 20V powered from a TPS55288 chip, but this also won't work. For testing I have bypassed the TPS55288 chip and have been providing 12V as source input into PP_HV. When I read the Status register, it is indicating that no USB connection has been made. It is also showing a fault on the PP_HVswitch. I believe a lot of the issues I am seeing are due to the lack of cable detection, and possible wrong GUI configuration.
Schematic, Register dump, and GUI settings are attached below.
When I created a new project I selected the TPS65982(NRND) -> Standard -> None -> Dual Role Port(DRP) prefers power source.
When configuring the settings in the Application Customization Tool GUI, I am a bit confused on the wording of some of the options. In GUI on the System Configuration area, PP_5V0 can only be disabled or set as an output. In the TPS65982 datasheet on page 91, PP_5V0 looks like an input. In our setup PP_EXT(5V), PP_5V0, and PP_HV(12V) are all inputs, yet if I set try to set these as an input my USB-C device does not charge. In our application VBUS should be the only output, unless I am misunderstanding how these are labeled as inputs or outputs.
What exactly is PP_HVE, it is listed in the GUI but not the datasheet. It seems to be related to PP_EXT, when PP_HVE is set as an output by itself, it can charge my USB-C device.
I am also confused how the TPS65982 chooses which source to power a USB-C device from? When I disable PP_5V0, and set PP_HVE as an output, I can charge a USB-C device from PP_EXT(VIN_Z), but when I turn both PP_5V0 and PP_HVE as outputs, the USB-C device only charges from PP_5V0. When I turn off the power source to PP_5V0, PP_HVE will not switch to start charging the USB-C device. The inability to mux right now is probably due to the cable connection not being detected.
I believe the C_CC pin configuration may be responsible for detecting cable orientation but why might the TPS65982 not detect a cable connection at all?
For the register values I referenced the TPS65981, TPS65982, and TPS65986 Host Interface Technical Reference Manual.
Before USB connection the Status register (0x1A) reads 0x60000400, a 4(0100) in the 2nd byte, bits 11:10, indicates "PP_HV switch currently disabled due to fault (system output).". I can't figure out what would be causing this. 00 in the first byte indicates that no plug is present.
After a USB connection is made the Status register reads 0x6d022400. The PP_HV switch is still disabled due to a fault. The first byte still reads 00 with no plug present.
Could the PP_HV fault be causing the lack of cable detection?
Attached below is the Schematic for how the TPS65982 is connected.
Here is the configuration settings I used for the TPS65982. The application GUI would not let me save the project due to an error that I could not resolve, so I saved screenshots and zipped them.
Application Custimization Tool_Configuration.zip
Here is the Register output for no USB connection Vs a Connected device.