RXM-GPS-F4-T Linx Technologies, RXM-GPS-F4-T Datasheet - Page 42

• Manufacturer Part Number: RXM-GPS-F4-T
• Description: GPS Modules F4 Series GPS Recvr Module Tape and Reel
• Manufacturer: Linx Technologies

Specifications of RXM-GPS-F4-T

• Rohs: yes
• Frequency Band: 1575.42 MHz
• Number Of Channels: 48
• Time To First Fix (cold Start): 32 s
• Acquisition Sensitivity: - 159.5 dBm
• Horizontal Position Accuracy: 3 m
• Operating Supply Voltage: 1.8 V
• Operating Supply Current: 56 mA
• Interface Type: Serial
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Dimensions: 15 mm x 13 mm x 2.2 mm
• Minimum Operating Temperature: - 30 C

Board Layout Guidelines
The module’s design makes integration straightforward; however, it
is still critical to exercise care in PCB layout. Failure to observe good
layout techniques can result in a signifi cant degradation of the module’s
performance. A primary layout goal is to maintain a characteristic
50-ohm impedance throughout the path from the antenna to the module.
Grounding, fi ltering, decoupling, routing and PCB stack-up are also
important considerations for any RF design. The following section provides
some basic design guidelines which may be helpful.
During prototyping, the module should be soldered to a properly laid-out
circuit board. The use of prototyping or “perf” boards will result in poor
performance and is strongly discouraged.
The module should, as much as reasonably possible, be isolated from
other components on your PCB, especially high-frequency circuitry such as
crystal oscillators, switching power supplies, and high-speed bus lines.
When possible, separate RF and digital circuits into different PCB regions.
Make sure internal wiring is routed away from the module and antenna, and
is secured to prevent displacement.
Do not route PCB traces directly under the module. There should not be
any copper or traces under the module on the same layer as the module,
just bare PCB. The underside of the module has traces and vias that could
short or couple to traces on the product’s circuit board.
The Pad Layout section shows a typical PCB footprint for the module. A
ground plane (as large and uninterrupted as possible) should be placed on
a lower layer of your PC board opposite the module. This plane is essential
for creating a low impedance return for ground and consistent stripline
performance.
Use care in routing the RF trace between the module and the antenna or
connector. Keep the trace as short as possible. Do not pass under the
module or any other component. Do not route the antenna trace on
multiple PCB layers as vias will add inductance. Vias are acceptable for
tying together ground layers and component grounds and should be used
in multiples.
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