The Si512xx family is a customizable solution generating frequencies from 3 to 200 MHz in 2 to 3 LVCMOS output configurations. It takes either crystal or reference clock input and generates desired frequencies using the on-chip low power, high performance PLL. AC parameters, like rise/fall times, can be customized to reduce EMI compliance issues. As further insurance against EMI issues, these devices can be customized to generate spread spectrum clocks with 0.25 - 1.0% center spread. The SSON# input enables or disables spread spectrum clock generation and the SSEL input selects between two pre-set spread percentages ranging from ±0.25 to ±1%. All the customer configurations are stored in the on chip OTP memory programmed at the factory. While these devices are powered from supply voltages that range from 1.8 to 3.3 V, the outputs can be powered from a lower power supply voltage than the main supply to support customer designs using ICs of different process technologies that have differing maximum input voltage requirements. Up to two I/O pins can be programmed to input functions including OE (Output Enable), PD# (Power Down) and FSEL (Frequency Select that switches between two pre-set frequencies on one output).