ADL5513 log detector Temperature data required

Dear Sir,

             I am using log detector ADL5513ACPZ in my design.I have tested the log detector in following conditions.

Operating Freq Range:1.6GHz

Voltage applied to TADJ pin : 0.88V

1. 1.Condition1-Ambient temperature(+25 Deg C)

RF input to log detector= -12dBm

Measured Output voltage= 1.6V

1. 2.Condition2-Low temperature(-10 Deg C)

RF input to log detector= -8dBm

Measured Output voltage= 1.6V

1. 3.Condition3-High temperature(-+55 Deg C)

RF input to log detector= -15dBm

Measured Output voltage= 1.6V

From the above results,we observed that 80mV(+/-4dB) variation at output of log detector over the temperature -10Deg C to +55Deg C.But in Datasheet it is mentioned that,max output variation over the temperature -40DegC to +85DegC is 10mV(+/-0.5dB).

please explain the reason for the above results.

Expecting your reply at the earliest.

Regards,

Wayne