WA_DEV_W228_PTS_002 Rev
001
Page 104 of 108
Product Technical Specification &
Customer Design Guidelines
PCB Specifications for the Application Board
In
order
to
save
costs
for
simple
applications,
a
cheap
PCB
structure
can
be
used
for
the
application
board
of
the
WISMO228.
A
4
‐
layer
through
‐
hole
type
PCB
structure
can
be
used.
Figure 51. PCB Structure Example for the Application Board
Note:
Due to the limited layers of 4-layer PCBs, sensitive signals like audio, SIM and clocks cannot be
protected by 2 adjacent ground layers. As a result, care must be taken during PCB layout for these
sensitive signals by avoiding coupling to noisy baseband through adjacent layers.
Environmental Specifications
The
WISMO228
is
compliant
with
the
following
operating
classes.
The
table
below
lists
the
ideal
temperature
range
of
the
environment.
Table 48. Operating Class Temperature Range
Conditions
Temperature Range
Operating / Class A
-20 °C to +55°C
Operating / Class B
-40 °C to +85°C
Storage
-40 °C to +85°C
Function Status Classification
Class A
The
WISMO228
remains
fully
functional,
meeting
GSM
performance
criteria
in
accordance
with
ETSI
requirements,
across
the
specified
temperature
range.
Summary of Contents for WISMO228
Page 116: ......