Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 85 of 92 21.12.2001
6.7 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 TC35 or TC37
module.
Despite of this, the antenna port, the SIM interface, the ACCU_TEMP port, the POWER port
and the Battery lines are equipped with spark gaps and clamp diodes to protect these lines
from overvoltage. For all the other ports, ESD protection must be implemented on the
application platform that incorporates the GSM engine.
TC35 and TC37 have been tested and found to comply with the EN 61000-4-2 directive. The
measured values verified for the Siemens reference configuration can be gathered from the
following table.
Table 39: Measured electrostatic values
Pin No. Signal name Indirect discharge
(environment)
Direct discharge
(air discharge to TC35/TC37)
1 - 5 VBATT+ >4kV 8kV
6 - 10 GND >4kV 8kV
11 - 12 POWER >4kV 8kV
13 VDD >4kV 1kV
14 ACCU_TEMP >4kV 8kV
15 /IGT >4kV 1kV
16 - 23 RS-232 signals >4kV 1kV
24 - 29 SIM signals >4kV 8kV
30 VDDLP >4kV 1kV
31 /PD >4kV 1kV
32 SYNC >4kV 1kV
33 - 40 Audio >4kV 1kV
Antenna RF GND >4kV 8kV
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.