Should the LMD18245 control inputs be given additional protection, in case of signal applied when power is off, or in case of ESD?
The control inputs are high impedance inputs and their input current spec is +/-10uA. Most microcontroller output pins can source 5 or 6 mA or less out of most of their I/O pins. But most microcontrollers also have a few high current I/O pins. When a logic high is on the microcontroller output and the microcontroller sourcing current into the control pins of the LM18245 is less than 5 or 6 mA, no damage whatever will be done. If the current can be 8 to 10mA [or more] then a current limiting resistor should be used. If the output of the microcontroller is low, then there is no issue because a low output connected to an unpowered input will produce little current flow. The same comments apply to all the DAC inputs. The inputs are not particularly ESD sensitive so no additional protection is needed for ESD. But noise or voltage spikes on the input lines [below the 12V maximum rating, of course] always have the chance to make the part act differenly from what you intended. So if you can se
