Part Number: AMC7834EVM
Other Parts Discussed in Thread: AMC7834
We have done tests with the AMC7834EVM using the indicated external power supply (DC 24V1A) and with two different setups: the kit programmer and a microcontroller for a custom application in develpment.
At first, the SPI communication witht the microcontroller was failing, showing noise when monitored with a logic analyzer. We also noticed that the SDO signal was not pulled up when innactive.
We needed to swich from 3.3V to 5V as IOVDD and use a pull-up resistor and a bridge for level conversion for the communication to work with our 3.3V setup, which was not specified in the datasheet of the part. The following image shows the SPI protocol when trying to read the ID register using 3.3V for IOVDD without any pull-up resistor.
When testing the external ADC conversion, we noticed that the EXTADC1 was not working properly, the result was always saturated at 0x0FFF. We tried the same initialization with other channels and they worked as espected. (Same error at both setups)
Finally after testing the response of the device in several DAC and ADC conversions, we noticed that the device was unusually hot. Ever since, the external ADC conversion has not worked properly anymore and the part (AMC7834) and some devices at the power subsystem of the EVM start heating fast after powering the device, even with no connections at all.
We beleive internal damage was caused to the device during testing, but we have not made improper use of the device. We would like to have a replacement of the part and assistance for the setup in order to include this part correctly in our project.
