User's Manual

Table Of Contents
9/29/2004 OV4F2
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BCM2035 User Manual
04/23/03
Broadcom Corporation
Page 24 Low Power Oscillator Document 2035-UM100-R
EXTERNAL FREQUENCY REFERENCE
An external frequency reference such as those generated by a TCXO signal may be directly connected to the
XTAL_IN pin on the
BCM2035 as shown in Figure 7.The external frequency reference input is designed to not
change the loading on the TCXO when the BCM2035 is powered up or powered down.
Figure 7: BCM2035 TCXO Configuration
LOW POWER OSCILLATOR
The
BCM2035 uses the LPO clock to provide low power mode timing for park, hold, and sniff modes of
operation. The LPO clock can either be provided externally to the device from a 32.768 kHz source or the
BCM2035 can operate using the internal LPO clock.
The accuracy of the internal LPO will limit the maximum park, hold, and sniff intervals.
An optional external resistor (120k, 5%) can be used with the BCM2035 to increase the accuracy of the internal
LPO.
XTAL_IN
XTAL_OUT
BCM2035
1000pF
No Connect
TCXO