EP1S40B956C5 Altera, EP1S40B956C5 Datasheet - Page 338

• Manufacturer Part Number: EP1S40B956C5
• Description: IC STRATIX FPGA 40K LE 956-BGA
• Manufacturer: Altera
• Series: Stratix®r

Specifications of EP1S40B956C5

• Number Of Logic Elements/cells: 41250
• Number Of Labs/clbs: 4125
• Total Ram Bits: 3423744
• Number Of I /o: 683
• Voltage - Supply: 1.425 V ~ 1.575 V
• Mounting Type: Surface Mount
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 956-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Number Of Gates: -

Enhanced PLLs
Figure 1–15. Spread-Spectrum Circuit Block Diagram
1–28
Stratix Device Handbook, Volume 2
refclk
Spectrum
Counter
Spread
Figure 1–16
different counter values. Since the enhanced PLL switches between two
different m and n values, the result is a straight line between two
frequencies, which gives a linear modulation. The magnitude of
modulation is determined by the ratio of two m/n sets. The percent
spread is determined by:
percent spread = (f
The maximum and minimum VCO frequency is defined as:
f
f
VCOmax
VCOmin
= (m
= (m
2
1
shows a VCO frequency waveform when toggling between
/n
n count1
/n
2
1
)
)
VCOmax
f
f
ref
ref
÷ n
f
VCOmin
)/f
n count2
VCOmax
m count1
= 1 [(m
2
PFD
÷ m
n
Altera Corporation
1
)/(m
m count2
1
July 2005
n
2
)]
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