Murata DNT24 Series, Руководство по интеграции

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6.4 Power Supply and Input Voltages
DNT24 radio modules can operate from an unregulated DC input (Pad 19) in the range of 3.3 to 5.5 V with a maximum
ripple of 5% over the temperature range of -40 to 85 °C.
Applying AC, reverse DC, or a DC voltage outside the range giv-
en 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_EXT_REF (Pad/Pin 25). Applying a voltage to a logic or analog input outside of its operating range can damage the
DNT24 module.
6.5 ESD and Transient Protection
The DNT24C and DNT24P 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 connections are made to sensors
with long leads.
Inadequate transient protection can result in damage and/or create a fire and safety hazard.
6.6 Interfacing to 5 V Logic Systems
All logic signals including the serial ports on the DNT24 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 DNT24 signal inputs. The
output voltage swing of the DNT24 3.3 V signals is sufficient to drive 5 V logic inputs.
Figure 6.6.1
6.7 Mounting and Enclosures
DNT24C and DNT24CA radio modules are mounted by reflow soldering them to a host circuit board. DNT24P and
DNT24PA modules are mounted by plugging their pins into a set of mating connectors on the host circuit board. Refer to
Section 8.3 for DNT24P connector details.
DNT24 enclosures must be made of plastics or other materials with low RF attenuation to avoid compromising antenna
performance where antennas are internal to the enclosure. Metal enclosures are not suitable for use with internal anten-
nas as they will block antenna radiation and reception. Outdoor enclosures must be water tight, such as a NEMA 4X en-
closure.
DNT24
©2009-2014 by Murata Electronics N.A., Inc.
DNT24 Integration Guide R2.0 - 10/27/14
www.murata.com