lan9311 Standard Microsystems Corp., lan9311 Datasheet - Page 456

• Manufacturer Part Number: lan9311
• Description: Lan9311/lan9311i Two Port 10/100 Managed Ethernet Switch With 16-bit Non-pci Cpu Interface
• Manufacturer: Standard Microsystems Corp.

Revision 1.2 (04-08-08)
15.6
Crystal Cut
Crystal Oscillation Mode
Crystal Calibration Mode
Frequency
Frequency Tolerance @ 25
Frequency Stability Over Temp
Frequency Deviation Over Time
Total Allowable PPM Budget
Shunt Capacitance
Load Capacitance
Drive Level
Equivalent Series Resistance
Operating Temperature Range
n/a XI Pin Capacitance
n/a XO Pin Capacitance
PARAMETER
The LAN9311/LAN9311i can accept either a 25MHz crystal (preferred) or a 25MHz single-ended clock
oscillator (+/- 50ppm) input. If the single-ended clock oscillator method is implemented, XO should be
left unconnected and XI should be driven with a nominal 0-3.3V clock signal. The input clock duty cycle
is 40% minimum, 50% typical and 60% maximum.
It is recommended that a crystal utilizing matching parallel load capacitors be used for the crystal
input/output signals (XI/XO). See
Note 15.12 The maximum allowable values for Frequency Tolerance and Frequency Stability are
Note 15.13 Frequency Deviation Over Time is also referred to as Aging.
Note 15.14 The total deviation for the Transmitter Clock Frequency is specified by IEEE 802.3 as
Note 15.15 This number includes the pad, the bond wire and the lead frame. PCB capacitance is not
Note 15.16 +70
Clock Circuit
application dependant. Since any particular application must meet the IEEE +/-50 PPM
Total PPM Budget, the combination of these two values must be approximately +/-45 PPM
(allowing for aging).
+/- 50 PPM.
included in this value. The XO/XI pin and PCB capacitance values are required to
accurately calculate the value of the two external load capacitors. These two external load
capacitors determine the accuracy of the 25.000 MHz frequency.
o
Table 15.15 LAN9311/LAN9311iCrystal Specifications
C
o
C for commercial version (LAN9311), +85
SYMBOL
F
F
F
F
P
C
temp
C
R
fund
age
tol
W
O
L
1
Table 15.15
DATASHEET
MIN
0.5
0
-
Parallel Resonant Mode
-
-
-
-
-
-
-
-
-
456
Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface
Fundamental Mode
for crystal specifications.
AT, typ
+/-3 to 5
25.000
20 typ
NOM
7 typ
3 typ
3 typ
-
-
-
-
-
-
o
C for industrial version (LAN9311I)
+70Note 1
+/-50
+/-50
+/-50
MAX
5.16
30
-
-
-
-
-
-
-
SMSC LAN9311/LAN9311i
UNITS
PPM
PPM
PPM
PPM
Ohm
MHz
mW
pF
pF
o
pF
pF
C
Note 15.12
Note 15.12
Note 15.13
Note 15.14
Note 15.15
Note 15.15
NOTES
Datasheet