80- and 120-MHz waveform generators cut jitter and distortion

March 04, 2014 // By Graham Prophet
Agilent’s 33600A Series waveform generators use the company’s “Trueform” signal-generation technology that claims to output the lowest jitter, lowest harmonic and non-harmonic distortion in this class of instruments.

Comprising four different one- and two-channel models, the units can generate waveforms up to 120 MHz at a 1 Gsample/sec sampling rate. The waveform generators provide the lowest jitter (less than 1 psec jitter, or 200x better than previous generation Direct Digital Synthesis – DDS – generators) and lowest total harmonic distortion in their class. With total harmonic distortion less than 0.03% and non-harmonic spurs below -75 dBc, the 33600A Series offers clean signals that don’t introduce noise, enabling users to get more accurate results.

The 33600A Series’ very low jitter and 3-nsec rise and fall times also allow users to set trigger points more accurately. A low voltage range, 1 mVpp, enables them to make output changes down to 1 µV—a critical capability when testing today’s low-voltage circuits and designs.

33600A Series users can take advantage of easy software upgrades to expand their instruments’ capabilities, such as when they need to increase memory to 64 Msamples or bandwidth to 120 MHz, for example. They can upgrade their instruments to NISPOM file security.

While traditionally DDS has been the waveform-generation technology of choice, its intrinsic limitations mean users often have to work around its compromised performance or spend up to five times more for a high-end waveform generator. Trueform technology eliminates these challenges by combining the best of DDS with a point-per-clock architecture. Using an exclusive digital sampling technique, it is able to deliver unmatched performance and superior signal fidelity, Agilent claims, at the same price customers expect with DDS. When used in the 33600A Series, the results are a range of capabilities not normally found on waveform generators in this class, including:

- Waveform summing and combining for easily adding noise to signals for margin and distortion testing using only a single channel. On the two-channel 33600A Series model users can sum and combine up to four signals.

- Variable-bandwidth noise for adjusting the bandwidth of the built-in noise