User's Manual

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Figure 17 shows the MIMO antenna spacing. The distance between ANT1 and ANT2 must be greater
than half the wavelength (62.5 mm at 2.4 GHz).
Figure 17. MIMO Antenna Spacing
Follow these supply routing guidelines:
• For power supply routing, the power trace for V
BAT
must be at least 40-mil wide.
• The 1.8-V trace must be at least 18-mil wide.
• Make V
BAT
traces as wide as possible to ensure reduced inductance and trace resistance.
• If possible, shield V
BAT
traces with ground above, below, and beside the traces.
Follow these digital-signal routing guidelines:
• Route SDIO signal traces (CLK, CMD, D0, D1, D2, and D3) in parallel to each other and as short as
possible (less than 12 cm). In addition, each trace must be the same length. Ensure enough space
between traces (greater than 1.5 times the trace width or ground) to ensure signal quality, especially
for the SDIO_CLK trace. Remember to keep these traces away from the other digital or analog signal
traces. TI recommends adding ground shielding around these buses.
• Digital clock signals (SDIO clock, PCM clock, and so on) are a source of noise. Keep the traces of
these signals as short as possible. Whenever possible, maintain a clearance around these signals.
7 Ordering Information
Part number: WL1837MODCOM8I
Revision History
DATE REVISION NOTES
November 2014 * Initial draft
16
Revision History SWRU382–November 2014
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