The CY25403, CY25483 and CY25423 have three programmable PLLs that can be used to generate output frequencies ranging from 3 to 166 MHz. The advantage of having three PLLs is that a single device generates up to three independent frequencies from a single crystal. Input Reference Clocks The input reference clock can be either a crystal or a clock signal, for CY25403 and CY25423 while just a clock signal for CY25483. 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 CY25483 is 2.5V/3.0V/3.3V while that for CY25403 and CY25423 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 CY25403/CY25483 is a high voltage part that can be programmed to operate at any voltage 2.5V, 3.0V, or 3.3V while CY25423 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 four available clock sources and these clock sources are: XIN/EXCLKIN, PLL1, PLL2, and PLL3. Output clock source selection is done by using four out of four crossbar switch. Thus, any one of these four available clock sources can be arbitrarily selected for the clock outputs. This gives user a flexibility to have up to three independent clock outputs.