Proprietary radio modes: spurious emissions can affect regulatory
compliance
Revisions Affected:
Revision C and earlier
Details:
When device internal load capacitors are used
with the external 48-MHz crystal, energy couples from the crystal oscillator circuit to the
RF output. This coupling causes spurious emissions at N × 48 MHz from carrier frequency.
This includes, but is not limited to, the frequency bands supported by the device covered by
the following regulations:When using the +14-dBm RF power
amplifier
Workaround:
For compliance with affected standards,
external load capacitors might be needed for the 48-MHz crystal to reduce spurious
emissions. Internal capacitors (default 7-pF connected capacitance) must then be
disconnected internally.This
workaround is implemented by defining the following symbols in the included customer
configuration file (ccfg.c) available in all Software Development Kit (SDK)
examples:
#define SET_CCFG_MODE_CONF_XOSC_CAPARRAY_DELTA -128
#define SET_CCFG_MODE_CONF_XOSC_CAP_MOD 0