The CY25402, CY25482 and CY25422 have two programmable
PLLs that can be used to generate output frequencies ranging
from 3 to 166 MHz. The advantage of having two PLLs is that a
single device generates two independent frequencies from a
single crystal.
Input Reference Clocks
The input reference clock can be either a crystal or a clock signal,
for CY25402 and CY25422 while just a clock signal for CY25482.
The input frequency range for crystal (XIN) is 8 MHz to 48 MHz
and that for external reference clock (EXCLKIN) is 8 MHz to 166
MHz. The voltage range of the reference clock input for CY25482
is 2.5V/3.0V/3.3V while that for CY25402 and CY25422 is 1.8V.
This gives user an option for this device to be compatible for
different input clock voltage levels in the system.
VDD Power Supply Options These devices have programmable power supply options. The
CY25402/CY25482 is a high voltage part that can be
programmed to operate at any voltage 2.5V, 3.0V, or 3.3V while
CY25422 is a low voltage part that can operate at 1.8V.
Output Source Selection
These devices have programmable input sources for each of its
clock outputs. There are three available clock sources and these
clock sources are: XIN/EXCLKIN, PLL1, and PLL2. Output clock
source selection is done by using three out of three crossbar
switch. Thus, any one of these three available clock sources can
be arbitrarily selected for the clock outputs. This gives user a
flexibility to have two independent clock outputs.