EP2C8T144C8N Datasheet, PDF (217/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

PLLs in Cyclone II Devices
Figure 7–17. PLL Power Schematic for Cyclone II PLLs
10 μF
Ferrite Bead
1.2V Supply
GND
Conclusion
.1 µF
VCCINT
.001 µF
PLL<#>_VCCA
PLL<#>_GNDA
PLL<#>VCCD
PLL<#>_GND
GND
Repeat for Each PLL
Power & Groundset
Note to Figure 7–17:
(1) Applies to PLLs 1 through 4.
Cyclone II Device
VCCD & GND
The digital power and ground pins are labeled VCCD_ PLL<PLL number>
and GND_PLL<PLL number>. The VCCD pin supplies the power for the
digital circuitry in the PLL. Connect these VCCD pins to the quietest
digital supply on the board. In most systems, this is the digital 1.2-V
supply supplied to the device’s V_CCINT pins. Connect the VCCD pins to a
power supply even if you do not use the PLL. When connecting the V_CCD
pins to V_CCINT, you do not need any filtering or isolation. You can connect
the GND pins directly to the same ground plane as the device’s digital
ground. See Figure 7–17.
Cyclone II device PLLs provide you with complete control of device
clocks and system timing. These PLLs support clock
multiplication/division, phase shift, and programmable duty cycle for
your cost-sensitive clock synthesis applications.
Altera Corporation
February 2007
7–33
Cyclone II Device Handbook, Volume 1