3.5 Input Voltage
WSN802G radio modules can operated from an unregulated DC input (Pin 14) in the range of 3.0 V
(trough) to 3.63 V (peak) over the temperature range of -40 to 85
°
C.
Applying AC, reverse DC, or a DC
voltage outside the range given above can cause damage and/or create a fire and safety hazard. Further,
care must be taken so logic inputs applied to the radio stay within the voltage range of 0 to 3.3 V. Signals
applied to the analog inputs must be in the range of 0 to ADC_REF (Pin 25). Applying a voltage to a logic
or analog input outside of its operating range can damage the WSN802G module.
3.6 ESD and Transient Protection
WSN802G circuit boards are electrostatic discharge (ESD) sensitive. ESD precautions must be observed
when handling and installing these components. Installations must be protected from electrical transients
on the power supply and I/O lines. This is especially important in outdoor installations, and/or where con-
nections are made to sensors with long leads.
Inadequate transient protection can result in damage
and/or create a fire and safety hazard.
3.7 Interfacing to 5 V Logic System
All logic signals including the serial ports on the WSN802G are 3.3 V signals. To interface to 5 V signals,
the resistor divider network shown in Figure 3.7.1 below must be placed between the 5 V signal outputs
and the WSN802G signal inputs. The output voltage swing of the WSN802G 3.3 V signals is sufficient to
drive 5 V logic inputs.
Figure 3.7.1
3.8 Power-On Reset Requirements
When applying power to the WSN802G, the /RESET pin should be held low until the power supply volt-
age reaches 3.3 volts for 100 milliseconds.
3.9 Mounting and Enclosures
WSN802GC radio modules are mounted by reflow soldering them to a host circuit board. WSN802GP
modules are mounted by plugging their pins into a set of mating connectors on the host circuit board.
Refer to Section 10.3 and/or the WSN802G Data Sheet for mounting details.
WSN802G enclosures must be made of plastics or other materials with low RF attenuation to avoid com-
promising antenna performance where antennas are internal to the enclosure. Metal enclosures are not
suitable for use with internal antennas as they will block antenna radiation and reception. Outdoor enclo-
sures must be water tight, such as a NEMA 4X enclosure.
WSN802G
©2009-2015 by Murata Electronics N.A., Inc.
HN-210D/X, HN-214 D/X Rev. 2.0 01-16-15
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