High Performance Single-Chip 10/100 Non-PCI Ethernet Controller
Datasheet
Table 7.5 10BASE-T Tranceiver Characteristics
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Transmitter Peak Differential
Output Voltage
V
2.2
2.5
2.8
V
Note 7.12
OUT
Receiver Differential Squelch
Threshold
V
300
420
585
mV
DS
Note 7.12 Measured at the line side of the transformer, line replaced by 100Ω (+/- 1%) resistor.
7.6
Clock Circuit
The LAN9118 can accept either a 25MHz crystal (preferred) or a 25 MHz clock oscillator (±50 PPM)
input. The LAN9118 shares the 25MHz clock oscillator input (CLKIN) with the crystal input XTAL1 (pin
6). If the single-ended clock oscillator method is implemented, XTAL2 should be left unconnected and
CLKIN 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 LAN9118
crystal input/output signals (XTAL1, XTAL2). See Table 7.6, "LAN9118 Crystal Specifications" for crystal
specifications. Refer to SMSC Application Note AN10.7 - “Parallel Crystal Circuit Input Voltage Control”
and the LAN9118 Reference Schematic for additional information.
Table 7.6 LAN9118 Crystal Specifications
PARAMETER
SYMBOL
MIN
NOM
AT, typ
Fundamental Mode
Parallel Resonant Mode
MAX
UNITS
NOTES
Crystal Cut
Crystal Oscillation Mode
Crystal Calibration Mode
Frequency
F
-
-
25.000
-
MHz
PPM
PPM
PPM
PPM
pF
fund
o
Frequency Tolerance @ 25 C
Frequency Stability Over Temp
Frequency Deviation Over Time
Total Allowable PPM Budget
Shunt Capacitance
F
-
+/-50
Note 7.13
Note 7.13
Note 7.14
Note 7.15
tol
F
-
-
+/-50
temp
F
-
+/-3 to 5
-
age
-
-
+/-50
C
-
7 typ
-
-
O
Load Capacitance
C
-
20 typ
pF
L
Drive Level
P
0.5
-
-
-
mW
Ohm
W
Equivalent Series Resistance
Operating Temperature Range
R
-
-
30
+70
-
1
o
0
-
C
LAN9118 XTAL1 Pin
Capacitance
3 typ
pF
pF
Note 7.16
Note 7.16
LAN9118 XTAL2 Pin
Capacitance
-
3 typ
-
Note 7.13 The maximum allowable values for Frequency Tolerance and Frequency Stability are
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).
SMSC LAN9118
127
Revision 1.3 (05-31-07)
DATASHEET
SMSC [ SMSC CORPORATION ]
