2/24/2008 9T6WP
Preliminary Hardware Data Module
BCM7405
06/29/07
Crystal Requirements
Bro a d c o m Co rp o r a ti o n
Document
7405-1HDM00-R
Crystal Requirements Page 1-169
C
RYSTAL
R
EQUIREMENTS
The following lists are the known crystal and clock input requirements and constraints for the BCM7405 device.
3
RD
O
VERTONE
C
RYSTAL
O
SCILLATOR
The 3
rd
overtone crystal oscillator uses a 54-MHz crystal operating at the third overtone to generate the internal clock
required for the BCM7405.
Table 1-39: Electrical Specifications
Parameter
Symbol
Comment
Min.
Typ.
Max.
Unit
Operating Conditions
Supply voltage
VDD1p2
1.2V supply
1.1
1.2
1.3
V
VDD2p5
2.5V supply
2.25
2.5
2.75
V
Operating temperature
TEMP
Die temperature
0
–
125
o
C
Jitter
–
RMS jitter
–
2
–
ps
–
Peak-to-peak jitter
–
12
–
ps
Crystal Requirements
Package
–
HC-49/U
–
–
–
–
Tolerance
Tol
@25
o
C
–30
–
30
ppm
Stability
–
–
–30
–
30
ppm
Load
LD
parallel resonant 54 MHz
–
10
–
pF
Equivalent Series Res.
ESR
–
–
–
40
ohm
Drive Level
–
–
0.5
–
–
mW