Ahh - but it doesn't use a sidechain the way the Boss unit does.
With a sidechain (also called a trigger input), you plug the guitar directly into the suppressor and out to your first pedal. Then the actual gate part is used further down the chain. This means the gate's trigger circuit follows the sound of the guitar itself and cannot be triggered by noises generated in the chain, and don't need adjusting to compensate for different volume or noise levels (depending on drive and volume changes from the effects.
With single-ended noise gates (without the separate trigger circuit), the trigger is part of the gate circuit, so whenever you kick in an overdrive or compressor (or even a volume pedal), their performance changes.
If you make sure the gate part is after everything but the reverbs, delays and any digital stuff, the sound will be quite natural.
Set up properly, it will look something like this:
That's not completely clear with the automatic resizing the forum does, so take a look at the big version
I have an article on effects chains that covers this a bit: http://ratcliffe.co.za/articles/effectchain.shtml