A quick look through a thermal camera shows the hotspots of the DDS ONE board. As you can see the biggest heat dissipation comes from the variable gain amplifier and the linear dropout regulator. In this configuration with which the pictures were taken, the LDO is driven with 8V input voltage. With its 5V output voltage and the 300mA current consumption the LDO nearly consumes 1W. Refering to the datasheet this is not a safe operation point without heatsinking the device (LM2940: 0.574W allowed without heatsink). Normally I drive the board with a 6V power supply, but I was interested to see whats going on when I exceed the input voltage limit.