不同应用的抖动要求.pdf

Application Relevance of Clock Jitter AN-827 APPLICATION NOTE Introduction Clock Jitter is commonly used to describe the performance requirements of oscillators and PLLs when driving high performance components like FPGAs, Microprocessors, and PHYs. But the plethora of clock jitter types, measurement methodologies, and corresponding specifications is broad and often leads to confusion. It is important to use the jitter type that is most appropr iate for the application of interest. The purpose of this Application Note is to provide some basic guidelines for selecting and quantifying the relevant jitter specification for a given application, as summarized in Table 1. Note: This Application Note is limited in scope in that it does not cover all jitter types, but the more common types are presented in detail. Table 1: Summary of Relevant Jitter by Application Application Relevant Specification (units) Qualifier (examples) Jitter Synchronous Interface Pk-Pk Period Jitter (time) Bit Error Rate Period Jitter Synchronous Logic RMS Period Jitter (time) 10K cycles Micro Complex Motherboard Design High Freq Jitter C2C Jitter (time) 1K consecutive cycles Spread Spectrum Phase Noise, PN Plot (dBc/Hz) Carrier Offs