FireWire
STINGRAY Technical Manual
V2.2.0
29
Figure 5: Block diagram of modern PC (X38 chipset by INTEL)
Caution
a
As mentioned earlier, it is
very
important
not
to exceed an
inrush current of 18 mJoule in 3 ms. (This means that a
device, when powered via 12 V bus power must
never
draw
more than 1.5 A, even not in the first 3 ms.)
Higher inrush current may damage the physical interface
chip of the camera and/or the phy chip in your PC.
Whereas inrush current is not a problem for one Stingray cam-
era, daisy chaining multiple cameras or supplying bus power
via (optional) HIROSE power out to circuitry with unknown
inrush currents needs careful design considerations to be on
the safe side.