BCM20706 Data Sheet
Clock Frequencies
Clock Frequencies
The BCM20706 embedded package supports 20, 24, and 40 MHz crystals (XTAL) by selecting the correct
crystal strapping options. Other frequencies also supported by firmware configuration. Table 4 lists the strapping
options.
Table 4: Crystal Strapping Options
Strapping Option Pin
BT_XTAL_STRAP_1 BT_XTAL_STRAP_0
XTAL Frequency
Pull Low
Pull Low
Pull High
Pull High
Pull Low
Pull High
Pull Low
Pull High
40 MHz
24 MHz
20 MHz
Read from serial flash or EEPROM
Crystal Oscillator
The XTAL must have an accuracy of ±20 ppm as defined by the Bluetooth specification. Two external load
capacitors in the range of 5 pF to 30 pF are required to work with the crystal oscillator. The selection of the load
capacitors is XTAL-dependent (see Figure 4).
Figure 4: Recommended Oscillator Configuration—12 pF Load Crystal
22 pF
XIN
Crystal
XOUT
20 pF
Broadcom®
Bluetooth SoC
May 19, 2016 • 20706-DS202-R
Page 19
BROADCOM CONFIDENTIAL
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