Part Number:DAC7760
We have been experiencing some failures in the field with DAC7760. This is the schematic of the circuit that we have.
These are the two failure modes that we are seeing:
1. We have no output from the DAC and seems like the DAC failed.
2. The other mode is where we have a failure the Isolated Power supply is shorted on the +24V side (pin 1 and pin 2 on U18).
The thermal pad is connected to AVSS. Since we are hand assembling it we have a solder slug that make the connection.
Any thoughts on why we are seeing this failure? How important is the thermal pad for the DAC to function efficiently. Our ambient temperature is mostly 25 °C but can be up to 45 °C. Nominally we have both current and voltage circuits enabled but only one is used. The current max is 10 mA for the worst case scenario.