July 1, 2010 -- Clocks provide the electronic heartbeat for a wide variety of consumer electronics, communications, and computing applications. These timing components deliver critical reference frequencies to processors, FPGAs, ASICs, DSPs, ADCs, DACs, memory, and physical layer devices.

The combination of frequencies required in a given application can change dramatically based on component selection of the other ICs in the system, since each processor, FPGA or other device can have unique frequency requirements. In addition, timing requirements can vary considerably from application to application based on performance, processing, and line rate requirements.

To satisfy this diverse range of requirements, the timing IC industry has responded by developing application-specific clocks. Each device is highly customized to meet the frequency, jitter, phase, and skew requirements for a particular application. These ICs are simple pin-controlled devices and require no firmware or configuration via a host processor. But this traditional approach has two significant limitations.

By James Wilson. (Wilson is with Silicon Laboratories, Inc.)