cy28159 Cypress Semiconductor Corporation., cy28159 Datasheet - Page 5

• Manufacturer Part Number: cy28159
• Description: Clock Generator For Serverworks Grand Champion Chipset Applications Semiconductor
• Manufacturer: Cypress Semiconductor Corporation.

Spread Spectrum Clock Generation (SSCG)
Spread Spectrum is a modulation technique applied here for
maximum efficiency in minimizing Electro-Magnetic Interfer-
Table 4. Spectrum Spreading Selection Table
Power Management Functions
Table 5. Host Swing Select Functions
Notes:
Document #: 38-07118 Rev. **
2.
3.
Multsel0
The entries in boldface are the primary system configurations of interest. The outputs should be optimized for these configurations.
Rr refers to the resistance placed in series with the Iref input and V
0
0
0
0
1
1
1
1
Unspread Frequency in MHz
MultSel1
133.3
0
0
1
1
0
0
1
1
100
200
Board Target
Trace/TermZ
60 Ohms
50 Ohms
50 Ohms
60 Ohms
60 Ohms
50 Ohms
60 Ohms
50 Ohms
[2]
F Min(MHz)
Reference Rr, Iref = Vdd(3*Rr)
132.66
199.5
Rr = 475 1%,Iref = 2.32 mA
Rr = 475 1%,Iref = 2.32 mA
Rr = 475 1%,Iref = 2.32 mA
Rr = 475 1%,Iref = 2.32 mA
Rr = 475 1%,Iref = 2.32 mA
Rr = 475 1%,Iref = 2.32 mA
Rr = 475 1%,Iref = 2.32 mA
99.5
SS
Iref = 2.32 mA
Rf = 475 1%,
.
Note 3
ence radiation generated from repetitive digital signals mainly
clocks. For a detailed explanation of Spread Spectrum Clock
Generation.
F Center(MHz)
Spread Spectrum Parameter
132.67
199.75
99.75
Downspreading
Output Current
Ioh = 5*Iref
Ioh = 6*Iref
Ioh = 5*Iref
Ioh = 6*Iref
Ioh = 4*Iref
Ioh = 4*Iref
Ioh = 7*Iref
Ioh = 7*Iref
F Max(MHz)
100
133
200
Voh@Z, Iref =
0.59V @ 50
0.85V @ 60
0.56V @ 60
0.47V @ 50
0.99V @ 60
0.82V @ 50
0.71V @ 50
07V@60
2.32 mA
Spread (%)
CY28159
–0.5%
–0.5%
–0.5%
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