How Video Works

CHAPTER 14

Digital Scopes

The digital signal differs from the analog signal in several ways, which will be discussed in this chapter. Because of the differences between these two signals, the appearance of a digital scope is quite different from that of an analog scope.

Digital Signal

While the digital signal, as with analog, is 1 volt peak-to-peak, some of the components and measurements within that 1 volt are displayed and measured differently on a digital scope. One volt is divided into a thousand units, each referred to as a millivolt, expressed as mV (Figure 14.1). On the graticule, 1 volt of digital video is displayed from –.3 volts (or –300 mV) to a peak of .7 volts (or 700 mV) for a total of 1 volt. Active digital video is displayed between ...