INA826S: Out put waveform when no signal input enable and disable ?

PYTsai,

Figure 72 shows how quickly the INA826S output responds when transitioning from a shutdown state to an enabled state and for that reason it is necessary to show a changing waveform. When the EN pin is pulled low, the INA826S output begins to track the input signal approximately 60 µs later. When transitioning from enabled to shutdown, as shown in Figure 73, the output of the INA826S stops tracking the input waveform in approximately 10 µs.
I am not sure what you mean that "there is no input signal"? Do you mean the inputs are not changing (are at DC) or they are floating?
In case of the INA826S being enabled, if the inputs are at DC, the output voltage will depend on the actual input voltages at each input terminal while if the inputs are floating, the output will also be floating. In case of INA826S being disabled, the output will be floating (will be in a high impedance state) regardless of what the inputs are.