LAN8720A-CP SMSC, LAN8720A-CP Datasheet - Page 75

• Manufacturer Part Number: LAN8720A-CP
• Description: TXRX ETHERNET 10/100 RMII
• Manufacturer: SMSC
• Type: Transceiverr

Specifications of LAN8720A-CP

• Number Of Drivers/receivers: 4/4
• Protocol: RMII
• Voltage - Supply: 1.6 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 24-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 638-1080

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
SMSC LAN8720A/LAN8720Ai
5.6
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
XTAL1/CLKIN Pin Capacitance
XTAL2 Pin Capacitance
PARAMETER
The device can accept either a 25MHz crystal or a 25MHz single-ended clock oscillator (±50ppm)
input. If the single-ended clock oscillator method is implemented, XTAL2 should be left unconnected
and XTAL1/CLKIN should be driven with a nominal 0-3.3V clock signal. See
recommended crystal specifications.
Note 5.18 The maximum allowable values for Frequency Tolerance and Frequency Stability are
Note 5.19 Frequency Deviation Over Time is also referred to as Aging.
Note 5.20 The total deviation for the Transmitter Clock Frequency is specified by IEEE 802.3u as
Note 5.21 0
Note 5.22 This number includes the pad, the bond wire and the lead frame. PCB capacitance is not
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).
±100 PPM.
included in this value. The XTAL1/CLKIN pin, XTAL2 pin and PCB capacitance values are
required to accurately calculate the value of the two external load capacitors. The total load
capacitance must be equivalent to what the crystal expects to see in the circuit so that the
crystal oscillator will operate at 25.000 MHz.
o
C for extended commercial version, -40
o
C
SYMBOL
F
F
F
F
P
Table 5.13 Crystal Specifications
C
temp
C
R
fund
age
tol
W
O
L
1
DATASHEET
Note 5.21
MIN
300
-
Parallel Resonant Mode
-
-
-
-
-
-
-
-
-
75
Fundamental Mode
AT, typ
+/-3 to 5
25.000
20 typ
NOM
7 typ
3 typ
3 typ
o
C for industrial version.
-
-
-
-
-
-
MAX
±50
±50
±50
+85
30
-
-
-
-
-
-
-
UNITS
PPM
PPM
PPM
PPM
Ohm
MHz
uW
Revision 1.2 (11-10-10)
pF
pF
o
pF
pF
C
Table 5.13
Note 5.18
Note 5.18
Note 5.19
Note 5.20
Note 5.22
Note 5.22
NOTES
for the