User's Manual

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Note d’étude / Technical document : URDx– OTL 5635.1– 007 / 70 230 Edition 03
Document Sagem Communications Reproduction et divulgation interdites
Sagem Communications document. Reproduction and disclosure prohibited
• Lines crossing shall be perpendicular
• Suitable other signals track width, thickness.
• Data bus must be protected by upper and lower ground plans
Radio
• Provide a 50 Ohm microstrip line for antenna connection
Audio (see also § 10.2)
• Differential signals have to be routed together, parallel (for example HSET_OUT_P/HSET_OUT_N).
• Audio signals have to be isolated, by pair, from all the other signals (ground all around each pair).
• Cancel any loops between VBAT and GND next to the speaker to avoid the TDMA burst noise in the speaker during
a communication.
• The single-end audio signal should be adopted the same rules as differential signals.
Figure 20: Layout of audio differential signals on a layer n
Figure 21: Adjacent layers of audio differential signals
*Warning: Magnetic field generated by VBAT tracks may disturb the speaker, causing audio burst noise. In this
case, one shall modify routing of the VBAT tracks to reduce the phenomena.
8.2 EXAMPLE OF LAYOUT FOR MMI BOARD
The figure Figure 22 shows an example of layer allocation for a 6 layers circuit (for reference only):
Figure 22: layer allocation for a 6 layers circuit
9. LABEL
The HiLo module is labelled with its own FCC ID(VW3HILOC) on its bottom side. When the module is installed
in customer’s product, the FCC ID label on the module will not be visible. To avoid this case, an exterior label
must be stuck on the surface of customer’s product signally to indicate the FCC ID of the enclosed module. This
Layer n-1
Layer n
Layer n+1
GND
HSET_OUT_P
GND
GND
HSET_OUT_P
GND
HSET_OUT_N
Layer 1: Components (HiLo)
Layer 2: Bus
Layer 3: Power supply
Layer 4: Complete GND layer
Layer 5: Audio, clocks, sensitive signals
Layer 6: GND,test points