I designed low noise 32-channel DAC modules for ion-trap applications.
And we observe that on some of the boards the DAC consumes much higher current on negative rail than specified.
I measure 60mA, this current heats the chip significantly and gets increased with every degree. At certain moment, the DAC and LDO gets hot and the LDO enters thermal shutdown. When I switch on cooling, the current gets back to 60mA and DAC works again.
When I cool the board intensively with fan, the current is stable but still roughly 60mA.
We compared the eval board with our board and so far found that on eval board the pin 13 (NC) is grounded which is floating on my board.
There are several boards that work perfectly OK with current consumption within specification.
The supply is generated from +/- 15V using two low noise LDOs which also supply the output amplifiers and filters.
Reference is also supplied from same +12V rail.
The voltages wake up in following sequence: 3.3V, +12V, -12V.
Here is full documentation including schematics and production files.