User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R08 Objective Specification Design-in
Page 147 of 188
The following input and equivalent parameters must be considered integrating a SARA-G350 ATEX module in an
application device intended for use in potentially explosive atmospheres:
 Total internal capacitance, Ci = 103 µF
 Total internal inductance, Li = 4.1 µH
 The module does not contain blocks which increase the voltage (e.g. like step-up, duplicators, boosters, etc.)
The nameplate of SARA-G350 ATEX modules is described in the ‘Product labeling’ section of the SARA-G3 series
Data Sheet [1]. Additional information can be found on the SARA-G350 ATEX modules’ certificate of compliancy
for use in potentially explosive atmospheres available on our website (www.u-blox.com).
The final enclosure of the application device integrating SARA-G350 ATEX modules, intended for use in
potentially explosive atmospheres, must guarantee a minimum degree of ingress protection of IP20.
2.14.2 Guidelines for VCC supply circuit design
The power supply ratings, average and pulse, must be considered in the design of the VCC supply circuit on the
application device integrating SARA-G350 ATEX module, implementing proper circuits providing adequate
maximum voltage and current to the VCC supply input of SARA-G350 ATEX modules, according to the specific
potentially explosive gas atmosphere category subdivision where the apparatus is intended for use.
The following maximum input and equivalent parameters must be considered in gas sub-division IIC:
 Ui = 3.8 V
 Ii = 1.6 A (burst)
 Pi = 2.5 W
 Ci = 103 µF
 Li = 4.1 µH
The following maximum input and equivalent parameters must be considered in gas sub-divisions IIB, IIA:
 Ui = 4.2 V
 Ii = 2.5 A (burst)
 Pi = 2.5 W
 Ci = 103 µF
 Li = 4.1 µH
Primary and secondary cells and batteries
Cells and batteries incorporated into equipment with intrinsic safety 'i' protection to potentially explosive gas
atmosphere shall conform to the requirements of the IEC 60079-0 [32] and IEC 60079-11 ATEX standards [33].
Shunt voltage limiters
For Level of Protection ‘ia’, the application of controllable semiconductor components as shunt voltage limiting
devices, for example transistors, thyristors, voltage/current regulators, etc., may be permitted if both the input
and output circuits are intrinsically safe circuits or where it can be shown that they cannot be subjected to
transients from the power supply network. In circuits complying with the above, two devices are considered to
be an infallible assembly.
For Level of Protection ‘ia’, three independent active voltage limitation semiconductor circuits may be used in
associated apparatus provided the transient conditions of the clause 7.5.1 of IEC 60079-11 standard are met.
These circuits shall also be tested in accordance with the clause 10.1.5.3 of the IEC 60079-11 standard [33].