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ICS8442 Datasheet, PDF (8/15 Pages) Integrated Circuit Systems – 700MHZ, CRYSTAL OSCILLATOR-TO-DIFFERENTIAL LVDS FREQUENCY SYNTHESIZER
◁
Integrated
Circuit
Systems, Inc.
ICS8442
700MHZ, CRYSTAL OSCILLATOR-TO-DIFFERENTIAL
LVDS FREQUENCY SYNTHESIZER
APPLICATION INFORMATION
STORAGE AREA NETWORKS
A variety of technologies are used for interconnection of the
elements within a SAN. The tables below lists the common fre-
quencies used as well as the settings for the ICS8442 to gener-
ate the appropriate frequency.
Table 8. Common SANs Application Frequencies
Interconnect Technology
Gigabit Ethernet
Fibre Channel
Infiniband
Clock Rate
1.25 GHz
FC1 1.0625 GHz
FC2 2.1250 GHz
2.5 GHz
Reference Frequency to SERDES
(MHz)
125, 250, 156.25
106.25, 53.125, 132.8125
125, 250
Crystal Frequency
(MHz)
25, 19.53125
16.6015625, 25
25
Table 9. Configuration Details for SANs Applications
Interconnect
Technology
Crystal Frequency
(MHz)
25
ICS8442
Output Frequency
to SERDES
(MHz)
125
25
Gigabit Ethernet
25
250
156.25
19.53125
156.25
25
Fiber Channel 1
25
53.125
106.25
Fiber Channel 2
16.6015625
132.8125
25
125
Infiniband
25
250
ICS8442
M & N Settings
M8 M7 M6 M5 M4 M3 M2 M1 M0 N1 N0
0 0 0 0 10 10 0 10
0 0 0 0 10 10 0 0 1
0 0 0 0 1 10 0 1 10
0 0 0 10 0 0 0 0 10
0 0 0 0 10 0 0 1 1 1
0 0 0 0 10 0 0 1 10
0 0 0 10 0 0 0 0 10
0 0 0 0 10 10 0 10
0 0 0 0 10 10 0 0 1
POWER SUPPLY FILTERING TECHNIQUES
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS8442 provides sepa-
rate power supplies to isolate any high switching noise from
the outputs to the internal PLL. VDD and VDDA, should
be individually connected to the power supply plane through
vias, and bypass capacitors should be used for each pin. To
achieve optimum jitter performance, better power supply
isolation is required. Figure 2 illustrates how a 10Ω along
|with a 10µF and a .01µF bypass capacitor should be
connected to each VDDA pin.
3.3V
VDD
.01µF 10Ω
VDDA
.01µF
10µF
FIGURE 2. POWER SUPPLY FILTERING
8442AY
www.icst.com/products/hiperclocks.html
REV. C JULY 8, 2004
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