Intel 82562EX, Руководство по конструкции

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82540EP/82541(PI/GI/EI) & 82562EZ(EX) Dual Footprint Design Guide
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3.3.4 Magnetics Modules for 82541xx Controller Applications
There are several different types of magnetics modules. For example, some magnetics modules
have USB connectors or RJ-45 connectors. There are also several discrete modules that can be used
for optimal performance. A gigabit magnetics module should be carefully selected for your design.
Table 11 lists suggested integrated magnetics modules for use with the 82541xx device. These
modules also contain integrated USB jacks. A good quality Gigabit Ethernet controller can also be
used with the 82562EZ(EX) PLC device.
Note: These components are pin-compatible with the magnetics modules shown in Table 7 for the
82562EZ(EX) PLC device.
3.3.5 Oscillators for 82541PI(GI) Controllers
The 82541PI(GI) clock input circuit is optimized for use with an external crystal. However, an
oscillator may also be used in place of the crystal with the proper design considerations:
•
The clock oscillator has an internal voltage regulator of 1.2 V to isolate it from the external
noise of other circuits to minimize jitter. If an external clock is used, this imposes a maximum
input clock amplitude of 1.2 V.
•
The input capacitance introduced by the 82541PI(GI) (approximately 20 pF) is greater than the
capacitance specified by a typical oscillator (approximately 15 pF).
•
The input clock jitter from the oscillator can impact the 82541PI(GI) clock and its
performance.
Table 11. 82541xx Recommended Magnetics Modules
Manufacturer Manufacturer's Part Number
Pulse (integrated) JW0A2P019D
Pulse (discrete) H5007
Table 12. 82541PI(GI) Clock Oscillator Specifications
Symbol Parameter
Specifications
Units
Min Typical Max
f0 Frequency 25 MHz
df0 Frequency Variation -50 +30 ppm
Dc Duty Cycle 40 60 %
tr Rise Time 5 ns
tf Fall Time 5 ns
σ
i Clock Jitter, rms (if specified) 50 ps
C1 Clock Capacitance (pushed by clock) 15 50 pF
VDD Supply Voltage 3.3 or 1.8 V
Operating
temperature 70 ° C
CMOS output
levels Voltage Output High (Voh),
Voltage Output Low (Vol) 80% VDD
20% VDD
V
V