PLLs in Cyclone II Devices
Figure 7–17. PLL Power Schematic for Cyclone II PLLs
Ferrite Bead
1.2V Supply
10 μF
GND
PLL<#>_VCCA
PLL<#>_GNDA
.1 µF
.001 µF
VCCINT
PLL<#>VCCD
PLL<#>_GND
GND
Cyclone II Device
Repeat for Each PLL
Power & Groundset
Note to Figure 7–17:
(1) Applies to PLLs 1 through 4.
VCCD & GND
The digital power and ground pins are labeled VCCD_ PLL<PLL number>
and GND_PLL<PLL number>. The VCCDpin 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 VCCINT pins. Connect the VCCD pins to a
power supply even if you do not use the PLL. When connecting the VCCD
pins to VCCINT, you do not need any filtering or isolation. You can connect
the GNDpins 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
Conclusion
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
ALTERA [ ALTERA CORPORATION ]
