User's Manual Part 2

MC75 Hardware Interface Description
Strictly confidential / Draft
s
MC75_V00.190a Page 72 of 91 15.02.2005
5.4 Electrostatic Discharge
The GSM engine is not protected against Electrostatic Discharge (ESD) in general.
Consequently, it is subject to ESD handling precautions that typically apply to ESD sensitive
components. Proper ESD handling and packaging procedures must be applied throughout
the processing, handling and operation of any application that incorporates a MC75 module.
Special ESD protection provided on MC75:
Antenna interface: one spark discharge line (spark gap)
SIM interface: clamp diodes for protection against overvoltage.
The remaining ports of MC75 are not accessible to the user of the final product (since they
are installed within the device) and therefore, are only protected according to the “Human
Body Model” requirements.
MC75 has been tested according to the EN 61000-4-2 standard. The measured values can
be gathered from the following table.
Table 17: Measured electrostatic values
Specification / Requirements Contact discharge Air discharge
ETSI EN 301 489-7
ESD at SIM port
± 4kV ± 8kV
ESD at antenna port
± 4kV ± 8kV
Human Body Model (Test conditions: 1.5 kΩ, 100 pF)
ESD at USB interface
± 1kV ± 1kV
ESD at SD card interface
± 1kV ± 1kV
ESD at all other interfaces
± 1kV ± 1kV
Note: Please note that the values may vary with the individual application design. For
example, it matters whether or not the application platform is grounded over external
devices like a computer or other equipment, such as the Siemens reference
application described in Chapter 8.