Preliminary Data Sheet
6/30/09
BCM4325
LPO Clock Interface
An additional frequency reference is the LPO clock that the BCM4325 uses to provide low-power mode timing for park, hold,
and sniff. The LPO clock should be provided externally to the device from a stable and accurate 32.768-kHz source.
Table 3: LPO Signal Requirements
Parameter
LPO Clock
Units
Nominal input frequency
Frequency accuracy
Duty cycle
32.768
200 a
kHz
ppm
30% to 70%
less than 1
–
Jitter (when FM is used)
Input signal amplitude
Signal type
Hz (integrated from 300 Hz to 15 kHz)
200 to 1800
Square wave or sine wave
mV, p-p
–
Input impedanceb
>100k
< 5
Ω
pF
®
a. +150 if FM is used. See Broadcom Bluetooth SoC Crystal, TCXO, RFIC, and LPO User Guide (43XX_20XX-1xx-R) for
details.
b. When power is applied, or switched off.
Broadcom Corporation
Document 4325-DS04-R
LPO Clock Interface
Page 9
CYPRESS [ CYPRESS ]
