TPS65987D: How to change the configuration on power duo board for no button press needed

Hi Chris,

The power duo EVM comes programmed with 4 potential configuration that the user can choose from. The default configuration only allows for 5V source capabilities while the buttons allow for a new configuration to load that allows for new source capabilities going up to 20V.

If you would like to have the TPS65987D offer 20V without any button being pressed, then you must update the default configuration so that the source capabilities no longer allow only 5V, but allow up to 20V.

You will need to use the application configuration tool to generate the new project file. You can watch the following video to help you get started

https://training.ti.com/tps6598x-application-customization-gui-tool-basic-introduction 

I will be using a wall wart style source so the EVM source board is not really something I need to worry about.  I get that I need to use the app config tool to generate a new project file, and I've seen the video and the the exact register which needs to change still isn't obvious. 

Does someone with a better knowledge of the TPS65987 know which register to change?

C

Chris,

You can view my response in this thread.

You can change the source capabilities of the device 1 configuration to whatever you need, and the TPS65987D will automatically advertise this upon initial connection by default

https://e2e.ti.com/support/interface/f/138/t/915371 

I'm not trying to change anything with the source.  It's the sink voltage request I'm trying to change to always take the highest power available. 

To configure the sink to request the maximum voltage without any button press you need to change the sink configuration using the same tool for changing the source configuration mentioned above.  It is just that you'll be changing a different register.  For sink configurations look at register 0x37 and 0x33.

I wonder if you could get what you want by holding down the 20V button all the time from before plugging in the wall wart.  Just a hunch, I don't have a board to try it myself here.

Deric, thanks for the feedback!

The overall usage of the GUI is a little confusing and I don't know if I missed something somewhere in the documentation or part of some video but I never did understand these basic questions:

When the GUI is connected does chip act the same?  Maybe not in debug mode?  If I make changes to settings when do they take effect or get saved?  I've become somewhat familiar with lots of trial and error and having to pull the plug on all the power and comms many times to get back to a basic starting point.  Sometimes the buttons and LEDs don't do anything and other times they do.

In any case, one general question I have that doesn't seem to be explained in the EVM docs is what really happens when you push those little buttons?

I looked at those registers you suggested and they do seem very relevant but probably not everything needed to replicate the button push.  My general approach was to push the buttons, look at raw register values, copy down hex data, and then try to re-write those same values later after a power reset.  I am talking to the device over I2C, when the GUI isn't connected, from a controller so that general approach could be replicated later. 

In the end, re-writing those two registers did not produce the same effect.  Perhaps there is another register needed to tell it to start sinking at those levels?

Thanks,

Chris

ps- holding the button down does work, but I will need more advanced functionality than that eventually so figured it was best to dive into things a bit more.  Next on my to do list will be to tell the chip to switch to a 5V OTG power source.

GPIO event #61-66 are used for the button functionality.  Besides those two registers you will need to issue the 'GSrC' 4CC command.