AMC7834EVM: Power supply issues

Hi Pablo,

Have you plugged in the SDM-USB-DIG and started up the GUI? The LDOs on the board are off by default, and get an enable signal from the GUI.

Thanks,
Erin

Hello Erin, thanks for your relpy.

I found in the schematics that the VUDT signal enables the TPS7A4700RGW device on the power subsystem, we were able to power de EVM correctly both with the GUI and the microcontroller we are using for our design. 

Now we can work in the initialization sequence for our application.

Hi Pablo,

Good to hear! Let me know if you have any questions about the device.

Thanks,
Erin

Hi Erin,

We have been using the EVM for a prototype design. We acquired the device about 3 months ago but just recently started testing it in depth. Unfortunately, we think we may have encountered a critical hardware failure.

Initially, we noticed that the external ADC channel 1 was always saturated even when left unconnected. Shortly after, the board started exhibiting unusually high power consumption. Both the AMC7834 and the TPS7A3301RGW (the negative supply LDO) reach high temperatures immediately upon power-up. This happens even with no external loads connected to the board, using only the factory-provided TI programmer.

Given that the TPS7A3301RGW is getting quite hot alongside the main IC, it suggests that there is permanent internal damage inside the AMC7834. This occurred using only the standard out-of-the-box setup and provided tools and the SPI port of a microcontroller (3.3V).

Because we are actively evaluating this part for an upcoming prototype design, is there any chance that we get an RMA or authorization for a replacement EVM so we can continue our development?

Thank you in advance,

Pablo.