User's Manual
For recommended layout pads for the module, please reference Mechanical Dimensions.
The area underneath the module should be covered with solder resist in order to prevent
short circuiting the test pads on the back side of the module. A solid ground plane is
preferred. Unconnected pins should be soldered to the pads, and the pads should be left
floating. For the module version with integrated antenna, the RF pad can be soldered, but
the pad should not be connected further. The two ground pads (pin10 and pin12 should be
grounded for all variants.)
When using the onboard chip antenna, careful attention is required to the layout of the PCB
where the module is mounted. In Figure 6 a mother PCB is shown with a recommended
placement of the module.
Figure 6: A recommended placement of the module on a mother PCB
(Shaded area is ground-plane on mother PCB)
18.0 FCC Approvals
The CT-EM2503 has been designed to meet all national regulations for World-wide use. Using
the integrated antenna it conforms to FCC CFR 47 Part 15 (USA).
This device complies with Part 15 of the FCC rules. Operation is subject to the following
two conditions: (1) this device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired
operation.
The device CT-EM2503 carries FCC authorization and is marked with the FCC ID Number.
Whilst any device into which this authorized module is installed will not normally be required to
obtain FCC authorization, this does not preclude the possibility that some other form of
authorization or testing may be required for the finished device.
When the CT-EM2603 module is integrated inside another device/product, then the outside
surface of that device/product must display a label referring to the enclosed module. This exterior
label can use wording such as “Contains Transmitter Module FCC ID: DI2CT-EM2603” or
“Contains FCC ID: DI2CT-EM2603”, although any similar wording that expresses the same
meaning may be used.
FCC statement:
If this equipment does cause harmful interference to radio or television reception, which can be
determined by turning the equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
—Reorient or relocate the receiving antenna.
—Increase the separation between the equipment and receiver.
—Connect the equipment into an outlet on a circuit different from that to which the receiver is