Mixed signal oscilloscope

A mixed signal oscilloscope (or MSO) has two kinds of inputs, a Small number (typically two or four) of analogue channels, and a larger number (typically sixteen) of digital channels. These measurements are acquired with a single time base, they are viewed on a single display, and any combination of these signals can be used to trigger the oscilloscope.

An MSO combines all the measurement capabilities and the use model of a Digital Storage Oscilloscope (DSO) with some of the measurement capabilities of a logic analyzer. MSOs typically lack the advanced digital measurement capabilities and the large number of digital acquisition channels of full-fledged logic analyzers, but they are also much less complex to use. 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.

Many of today’s designs include microprocessors and digital signal processors (DSPs) that combine analog signals with digital content. Debugging a mixed-signal design often includes correlating important handshaking activity while simultaneously verifying the analog components of the system. The digital signals in a design can be very fast, while the analog signals tend to be much slower.

Viewing and analyzing the many signals of interest within a microprocessor or DSP-based embedded design can be difficult or impossible using a conventional 2- or 4-channel digital storage oscilloscope (DSO). The increased complexity and faster digital speeds of clock rates and edge times require oscilloscopes with more channels and higher bandwidths.

In addition, if you want to view and analyze the fast digital and slower analog signals at the same time with high resolution, you need an oscilloscope that has deep memory. With deep memory, you can capture a longer amount of time, but unless the measurement device is very responsive, it can be difficult to find the portion of the signal you are interested in. Many of today’s designs include modulated signals and long serial streams, so it is important to be able to find the area of interest quickly and easily. For complex designs, easy triggering also is important.