An Oscilloscope measures and displays voltage signals, allowing observation of signal changes over time. Graphical representation of voltage (vertical Y axis) and time (horizontal X axis) enables analysis and debugging. An oscilloscope is an essential instrument for testing new circuitry, as well as diagnosing malfunctioning existing devices. An oscilloscope can be a bench top instrument or a handheld device; it can also be classified as analog or digital. Because of their advanced trigger, storage, display, and measurement features, digital oscilloscopes are normally preferred over analog. A digital oscilloscope uses an ADC (analog-to-digital converter) to convert the acquired signal voltage into digital sample points; the digital values are then turned back into an analog signal for display.
One type of digital oscilloscope is a digital storage oscilloscope (DSO). Digital storage oscilloscopes (DSOs) capture transients, or one-time events. DSOs are ideal for low
repetition-rate or single-shot, high-speed, multichannel design applications. Single-shot capture is particularly important when looking for intermittent faults, so a single-shot DSO is ideal for debugging and troubleshooting new designs. Digital storage oscilloscopes provide permanent signal storage and extensive waveform processing. However, DSOs typically have no real-time intensity grading; therefore, they cannot express varying levels of intensity in the live signal.
Digital phosphor oscilloscopes (DPOs) break down the barrier between analog and digital oscilloscope technologies. They are equally suitable for viewing high and low frequencies, repetitive waveforms, transients, and signal variations in real-time. Only a DPO provides the Z (intensity) axis in real-time that is missing from conventional DSOs. DPOs have dedicated unique ASIC hardware to acquire waveform images, delivering high waveform capture rates that result in a higher level of signal visualization. This performance increases the probability of witnessing transient events. A DPO is an ideal general purpose design and troubleshooting tool for a wide range of applications. DPOs are excellent for advanced analysis, communication mask testing, digital debug of intermittent signals, repetitive digital design and timing applications.
A third type of oscilloscope is the mixed signal oscilloscope (MSO). An MSO has two kinds of input, typically two or four analog channels and 16 digital channels. Powerful digital triggering, high resolution acquisition capability, and analysis tools make the MSO the tool of choice for quickly debugging digital circuits. An MSO combines all the measurement features of a DSO with some of the measurement capabilities of a logic analyzer. Typical mixed-signal measurement uses include the characterization and debugging of hybrid analog/digital circuits like: embedded systems, Analog-to-digital converters (ADCs), Digital-to-analog converters (DACs), and control systems.