BCM4330 Preliminary Data Sheet
External 32.768 kHz Low Power Oscillator
External 32.768 kHz Low Power Oscillator
The BCM4330 uses a secondary low frequency clock for low power mode timing.
A precision external 32.768 kHz clock that meets the specifications listed in Table 3 is required by the BCM4330.
Table 3: External 32.768 kHz Sleep Clock Specifications
Parameter
LPO Clock
Units
Nominal input frequency
Frequency accuracy
Duty cycle
Input signal amplitude
Signal type
Input impedanced
32.768
kHz
ppm
%
mV, p-p
–
±200a, b
30–70
200–1800c
Square-wave or sine-wave
>100k
<5
Ω
pF
Clock jitter (integrated over 300 Hz–15 kHz) <5
Clock jitter (during initial start-up) <10,000
ns
ppm
a. If FM RX is used: ±150 ppm maximum with frequency error indication, ±50 ppm without frequency error
indication.
b. If FM TX is used: ±100 ppm maximum with frequency error indication, ±50 ppm without frequency error
indication.
c. 200–1800 mVp-p to avoid additional current consumption and degradation in FM SNR. 3.3 Vp-p maximum.
d. When power is applied or switched off.
®
BROADCOM
BCM4330 Preliminary Data Sheet
April 28, 2011 • 4330-DS304-RI
Page 37
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