64 09 713 D3610
D3610
.
201.01.08
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02 09.2016
13
Sirona Dental Systems GmbH
2 Safety instructions
Operating Instructions and Installation XIOS XG USB module and sensors
2.11 Electrostatic discharge
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● audible at 5,000 V or higher (cracking, crackling)
● visible at 10,000 V or higher (arc-over)
The transient currents resulting from these discharges have a magnitude
of over 10 amps. They are not hazardous for humans because they last
for only several nanoseconds.
Tip: 1 nanosecond = 1/1,000,000,000 second = 1 billionth of a second
Voltage differentials exceeding 30,000 volts per centimeter may lead to a
charge transfer (electrostatic discharge, lightning, arc-over).
Integrated circuits (logical circuits and microprocessors) are used in order
to implement a wide variety of functions in a device. The circuits must be
miniaturized to a very high degree in order to include as many functions
as possible on these chips. This leads to structure thicknesses as low as
a few ten thousandths of a millimeter. Integrated circuits that are
connected to wires leading externally are therefore particularly at risk
from electrostatic discharge.
Even voltages that are imperceptible to the user can cause breakdown of
the structures, thus leading to a discharge current that melts the chip in
the affected areas. Damage to individual integrated circuits may cause
malfunction or failure of the unit.