精华全集 冲广角币 获取广角币的更多方法
【名称】：Jitter generation and measurement with off-the-shelf test equipment
【作者】: Slobodan Milijevic, Zarlink Semiconductor
【格式】: PDF
【页数】：8
【语言】：英文
【摘要或目录】：
During the component selection process for a new communication product, jitter characteristics
of Phase Locked Loops (PLLs) from different vendors are often evaluated to determine which
one is best suited for the application. If specialized test equipment is not available, such as a jitter
modulator, phase noise spectrum analyzer, and time interval analyzer, then standard test
equipment can be used.
This article will show that PLL jitter measurement can be done with a signal generator with phase
modulation (PM) or frequency modulation (FM) and a digital oscilloscope. Specifically, we will
outline how to measure jitter tolerance, jitter transfer, and jitter generation.
Jitter basics
Jitter is defined in ITU (International Telecommunication Union) and Telcordia specifications as
“short-term variations of a digital signal’s significant instance from their ideal position in time.”
Essentially, jitter is the term commonly used to describe the phase noise of digital signals.
The two parameters that fully define phase noise are amplitude and frequency. Phase noise at
frequencies below 10 Hz is referred to as wander, while phase noise at frequencies equal to or
larger than 10 Hz is called jitter.
