An issue about AD9874 | EngineerZone
Referring to the AD9874 datasheet, TPC 4 and 5 curves on page 9 show the maximum input signal (called "clip point") for a Max VGA attenuation and Min VGA attenuation over supply and temperature. Note the IF Input Clip Point specifications on page 3 (under SYSTEM DYNAMIC PERFORMANCE) are based on these characterization curves.....................with Min values of -20 and -32 dBm for VGA at max and min attenuation settings.
That said, the AD9874 also includes a 16 dB input attenuator under large signal conditions in which one can over drive the input signal beyond -20 dB with degraded performance. TPC7c on page 10 shows the gain compression characteristics when the attenuator is enabled.
Lastly, the ABSOLUTE MAX RATINGS state that the IF input voltage on either pin is limited to -0.3 and VDDI+0.3.