WG82574IT S LBAC Intel, WG82574IT S LBAC Datasheet - Page 441

• Manufacturer Part Number: WG82574IT S LBAC
• Description: CONTROLLER, ENET, INTEL 82574IT, 64PQFN
• Manufacturer: Intel

Specifications of WG82574IT S LBAC

• Ethernet Type: IEEE 802.3, IEEE 802.3u, IEEE 802.3ab
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: QFN
• No. Of Pins: 64
• Package / Case: QFN
• Interface Type: I2C, JTAG, PCI, SPI
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Design Considerations—82574 GbE Controller
Figure 70.
13.4
Recommended Crystal Placement and Layout
Oscillator Support
The 82574L clock input circuit is optimized for use with an external crystal. However, an
oscillator can also be used in place of the crystal with the proper design considerations
(see
• Place load capacitor solder pad directly in line with circuit trace (see
• Use 50 impedance single-ended microstrip traces for the crystal circuit.
• Route traces so that electro-magnetic fields from XTAL2 do not couple onto XTAL1.
• Route XTAL1 and XTAL2 traces to nearest inside corners of crystal pad (see
• Ensure that the traces from XTAL1 and XTAL2 are symmetrically routed and that
• The total trace length of XTAL1 or XTAL2 should be less than 750 mils.
• The clock oscillator has an internal voltage regulator of 1.9 V dc to isolate it from
• The input capacitance introduced by the 82574 (approximately 20 pF) is greater
point A).
No differential traces.
Figure
their lengths are matched.
the external noise of other circuits to minimize jitter. If an external clock is used,
this imposes a maximum input clock amplitude of 1.9 V dc. For example, if a
3.3 V dc oscillator is used, it's signal should be attenuated to a maximum of
1.9 V dc with a resistive divider circuit.
than the capacitance specified by a typical oscillator (approximately 15 pF).
Table 90
Crystal Pad
70, point B).
for detail clock oscillator specifications):
Capacitor
27pF
0402
“B”
Ethernet Controller
Less than 660 mils
Xtal2
Crystal
“A”
Xtal1
“B”
Capacitor
27pF
0402
Crystal Pad
Figure
70,
441