| 摘要 |
A waveform digitizer particularly suitable for use in electronic test systems for analyzing and displaying analog signals is disclosed. A digitally derived reference voltage is compared with the analog signal to be digitized during a series of comparison sequences. Simultaneously with the start of each comparison sequence a digital clock is started. Each time the analog signal rises above, or drops below, the reference voltage a decision change detector produces an enable pulse. Each time an enable pulse occurs, a data word, having a portion related to the value of the digitally derived reference voltage and a portion related to the digital clock value, is stored and/or used to control a display. At the end of the first comparison sequence (determined when the digital clock value reaches a predetermined level) the reference voltage is incremented and a second comparison sequence started. These steps are repeated until the reference voltage reaches a predetermined level. The resulting set of digital words is digitized equivalent of the waveform of the analog signal.
|
