BCM4319 Preliminary Data Sheet
Frequency Trimming
The BCM4319 is set at the factory to a default frequency of 30 MHz. For a typical design using a crystal, it is
recommended that the default frequency be used: for USB Mode, 30 MHz is required.
Frequency Trimming
The BCM4319 uses a fractional-N synthesizer to digitally fine tune the frequency reference input to within 2
ppm tuning accuracy. This trimming function can be applied to the crystal or an external frequency source such
as a TCXO. Unlike typical crystal trimming methods, the BCM4319 uses a fully digital implementation to change
the frequency, which is much more stable and tolerant of the crystal characteristics and temperature. The input
impedance and loading characteristics remain unchanged on either the TCXO or the crystal during the trimming
process and are unaffected by process and temperature variations.
Broadcom®
Single-Chip IEEE 802.11™ a/b/g/n MAC/Baseband/Radio
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April 2, 2014 • 4319-DS05-R
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