DDS-Based Signal Sources Conquer Semiconductor Characterization

With so many modern products relying on semiconductors, it is essential that the behavior of these devices be accurately evaluated. By emulating the waveforms found in actual applications, signal sources promise to help engineers accurately evaluate the behavior of some basic semiconductor devices. In “Semiconductor Device Characterization Counts on Flexible Stimulus Signals,” Tektronix, Inc. (www.tektronix.com) explains how such signal sources can be leveraged. The 12-page application note targets designers of new semiconductor devices as well as engineers designing those devices into end-user products.

The note begins with a brief overview of different characterization tests. It then delves into the use of signal sources in semiconductor measurement applications. When choosing a signal source, engineers generally understand the importance of key signal-source specifications like bandwidth and accuracy. Yet they should also make it a priority to consider secondary features. For example, say the device under test (DUT) requires extensive characterization of its response to pulse edge variations. In such a case, a signal source should provide adequate pulse-waveform characteristics. User-interface features also should be considered.

The remainder of the note is largely devoted to application examples. A sidebar delves specifically into direct digital synthesis (DDS), which is behind the latest generation of cost-effective, high-performance signal-source platforms. This digital methodology was designed to produce analog waveforms from input digital code. It provides very fast switching from one output frequency to another. It also delivers superior frequency resolution at a competitive cost.