逻辑分析仪是一种采集和显示数字电路信号的仪器。逻辑分析仪的最主要作用在于时序判定。逻辑分析仪不像示波器那样有许多电压等级，只显示两个电压，逻辑1和逻辑0，以及不确定x。设定了两个参考电压后，逻辑分析仪将被测信号通过比较器进行判定，高于第一个较高的参考电压者为逻辑1,低于第二个较低的参考电压者为逻辑0，低于第一个参考电压而高于第二个参考电压的为不确定x。

A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or may correlate assembly with source-level software. Logic Analyzers have advanced triggering capabilities, and are useful when a user needs to see the timing relationships between many signals in a digital system.