In the first paragraph of the AD8330 VGA data sheet on page 19 is a notice
concerning the optional use of a negative supply. But I am not able to find the
The absolute maximum supply voltage of the AD8330 is +6 V so it is NOT possible
to use it with +/- 5 V supplies. A +/- 5 V supply will destroy the AD8330.
The comment on page 19 of the data sheet refers to an application which was
left out of the final data sheet
in which the AD8330 was powered by a -5.2 V ECL supply where the system ground
is the positive line. Of course
the control signals are still referred to the negative line so care is
necessary to ensure that line voltage variations do not cause gain variation.
There is no particular reason why you should not use +/-2.5 V, or even +/- 3 V,
supplies so long as they are
well decoupled and the control signals are referred to the negative rail and
not the centre ground.