Hi Vera, Scenario 1: It is important to note that if any of the supplies are disconnected, the part with be in clamp mode, where the DAC outputs are resistively connected to VSS. 1) The highest potential VSS can be when it floating is about +.7V, as that is when the ESD protection diode is activated, but for that to happen, the DAC would need to be sinking current, which I think is unlikely. The output would certainly not be able to source any current, because the clamp resistor is only connected to VSS. 2) This would not change. Scenario 2: 1) In this case the device is still in CLAMP mode, with a resistor connecting the DAC output to VSS, or in this case, ground. If the load on the DAC output is drawing current, the output will go negative, as low as -0.7V, as that is when the ESD cell turns on. If it is sinking current, then the output would be positive. 2) This would not change anything, the output will track VSS with the CLAMP resistor. Thanks, Paul
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