The 271 field programmable VCXO clock synthesizer generates up to six high-quality, high-frequency clock outputs including multiple reference clocks from a low-frequency crystal input. It is designed to replace crystals and crystal oscillators in most electronic systems. Using IDT's VersaClockTM software to configure PLLs and outputs, the 271 contains a One-Time Programmable (OTP) ROM for field programmability. Programming features include VCXO, eight selectable configuration registers and up to two sets of three low-skew outputs. Each of the two output groups are powered by a separate VDDO voltage. VDDO may vary from 1.8 V to VDD. Using Phase-Locked Loop (PLL) techniques, the device runs from a standard fundamental mode, inexpensive crystal, or clock. It can replace VCXOs, multiple crystals and oscillators, saving board space and cost. The 271 is also available in factory programmed custom versions for high-volume applications.