LMP92066EVM: Can not communicate with LMP92066EVM eval board.

Hi David,

If you disconnect the USB2ANY from the LMP evm, can you launch the software without error?

If you revert to v1.18 and then launch the LMP92006EVM software (not USB2ANY explorer), can you connect then?

Thanks,

Paul

Hi Paul,

In the first scenario, I get this error.

And in the second scenario, I can not communicate with the EVM. I have random voltages on the rails. At least, with the updated USB2ANY firmware I could set the voltage rails and have stable voltages on the EVM. 

Thanks, David

Hi David,

The LMP92066EVM GUI requires the older firmware.  By connecting the USB2ANY to the USB2ANY Explorer Software, you have updated the EVM to the latest version.  I do not recommend you use the same USB2ANY interchangeably with the USB2ANY Explorer Software and the LMP92066 GUI.

Can you roll back the firmware using the procedure in the other post, and then launch the LMP92066EVM GUI? (Do not launch the USB2ANY explorer).

Thanks,

Paul

Hi Paul, 

I tried reflashing the firmware again (not launching the USB2ANY explorer). The USB2ANY board is not supplying 3.3 and 5V to the EVM board. I still can not communicate via the GUI. Am a missing a start-up procedure/ step-up in the GUI?

Thanks, David

When you test the 3.3V and 5V, are you connecting this to the LMP92066EVM?  

Let's try to isolate the two by removing the J3, J4, and J5 jumpers, then re-launch the LMP92066EVM GUI.  Measure the voltage on pin 3 on those two jumper headers.  If you still do not see 3.3V and 5V then it must be the USB2ANY rather than the EVM.

Thanks,

Paul

Paul, 

I am getting about ~180mV on the 5P0 rails and 0 V on the 3P3 rail. The USB2ANY was supplying the proper voltages before the downgrade in firmware but I had to EN using the Explorer software. Is there an equivalent to that in the EVM GUI?

Thanks, David

Paul, 

For more clarification, I am getting 5V and 3.3V on TP1 and TP4, respectively, on the USB2ANY board but the enable lines on the output switches U2 and U5 are low. How do I set those high?

-David

Hi David,

The 5V and 3.3V rails are disabled at startup, and can only be enabled through software.  In this case, the LMP92066EVM GUI should enable the rails at startup.  It is possible that it is enabling the rails, but something is shorting the supplies to a lower value. 

Lets try two experiments:

1. If they do not turn on, please disconnect the LMP92066EVM, then disconnect and reconnect the USB2ANY from you PC.  Launch the EVM software without connecting the LMP92066EVM to the USB2ANY.  Please measure the voltage on the output of the switches U2 and U5.  If the output of the switches do not change, then maybe the USB2ANY is damaged. If they do turn on, please try the next test.

2. Can you remove the jumper on the EVM as I described in my previous post, and then confirm if the rails turn on with the LMP92066EVM connected.  If they do not, then something one the EVM must be shorting them out.  If they do turn on, try connected the J3-5 jumpers and see if they turn off.  If they do, then we can still assume something is wrong with the LMP92066EVM.  

If we suspect the EVM, we could try connecting external supplies and measuring what the current load is on the supplies to help determine which supply is suspect.

In addition, have you added capacitors on the output of the LMP92066? C1-4?

Thanks,
Paul

Paul, 

Thanks for the suggestions. I tried Step 1 and the U2 and U5 switches did not turn on. I also went and got a new USB2ANY out of an eval box and I got the same result. Maybe the GUI is not the latest rev? Also, I am running Windows 10.

Please see attached photo and advise.

Thanks, 

-David