AD8362 Output Saturation

Hi again,

I've built a circuit to measure RF signals of 2.4GHz in accordance to Fig. 48 in the datasheet for singled ended drive. The only difference is that I have not put a capacitor on the CHPF pin and have connected it directly to GND. Everything else is as per the reference design for measurement mode (i.e. a combination of Fig 47 and 48).

During testing, I am measuring an output voltage of 5V no matter what I am applying to the input (this includes leaving it disconnected). The circuit draws a steady current approximately 25mA

Is there something obvious that I am missing here? I have already check for solder splash between VPOS and VOUT. The voltage on the INHI/INLO when the input is disconnected measures between 2.2V-2.5V, which i assume is also correct. 

This is the second chip that I have bought and results have been the same for both, so I dont think that it is a faulty chip.

This is for a project at university and even my supervisor/other academics have tried a range of things and cant seem to figure it out. Any suggestions?