User's Manual

Note d‘étude / Technical document :
URD1– OTL 5696.1– 003 / 72361 Edition 02
HILO 3G Application Note
17 January 2011 - Page 34 / 38
8.1.2 Power supplies
Layer for power supply signals (VBAT, VGPIO) is recommended.
Any loop of power signals layout must be avoided on the design.
Suitable power supply (VBAT, VGPIO) track width and thickness.
8.1.3 Clocks
Clock signals must be shielded between two grounds layer and bordered with ground vias.
8.1.4 Data bus and other signals
 Data bus and commands have to be routed on the same layer, none of the lines of the bus shall be parallel to other lines
 Lines crossing shall be perpendicular
Suitable other signals track width, thickness.
Data bus must be protected by upper and lower ground plans
8.1.5 Radio
 Provide a 50 Ohm micro strip line for antenna connection
8.1.6 Audio
Differential signals have to be routed together, parallel (for example HSET_P/HSET_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.
Figure 32: Layout of audio differential signals on a layer n
Figure 33: Adjacent layers of audio differential signals