News and New Products

1-μHz-to-240-MHz generator produces precision pulses, functions, noise, 14-bit arbitrary waveforms, and more

By Dan Strassberg, Contributing Technical Editor -- EDN, 1/28/2008

Design and test engineers are under increasing under pressure to quickly bring high-quality products to market and differentiate those products from their competition. Achieving these objectives requires new test protocols and new classes of instruments, says Alois Hauk, vice president and general manager of digital-photonic test at Agilent Technologies, which has introduced what the company calls the industry’s first generator to combine superior signal quality with the ability to produce such a wide variety of waveforms over such a broad frequency range. The 81150A pulse/function/arbitrary-waveform/noise generator employs a 512k-sample/channel arbitrary-waveform memory and a 14-bit DAC that operates as fast as 2G samples/sec. The generator can produce signals with repetition rates as low as 1 μHz with modulation at frequencies as high as 10 MHz. The unit, which produces many waveforms greater than 100 MHz and sine waves to 240 MHz, suits use in general-purpose bench tests and advanced serial-data stress tests.

The 81150A provides versatile generation of pulses with tight control over transition times and other parameters; standard, arbitrary, and modulated waveforms; and noise for stress testing. The generator works well with the manufacturer’s 5/6/80000 Infiniium real-time oscilloscopes and DCA-J sampling oscilloscope for serial-data testing. Integration of many functions into one instrument minimizes cabling, space, and test-setup time.

Engineers must create ideal and worst-case signals to obtain rapid, accurate insights into designs for such devices as semiconductor circuits, sensors, and modulators. The 81150A’s accurate signals help engineers to test their devices—not the signal source. “When signal fidelity matters, ‘just enough’ signal quality isn’t enough,” says Hauk. “Versatile waveforms and the most precise signals are key contributors to developing quality products within a reduced design cycle. The pulse/function/arbitrary-waveform/noise generator supports engineers through each development phase, and the patented noise generator enables a quantum leap in productivity.”

The instrument provides both “random” and calibrated, deterministic noise for repeatable stress tests. (Although the random noise is not truly random, it might as well be; you can set the signals to repeat as infrequently as every six to 12 hours but you can also choose much more frequent repetition.) You can define various stress tests simply by adjusting the crest factor, a measure of signal quality equal to the ratio of peak or peak-to-peak to rms voltages.

The 81150A features accurate signals that test the device—not the source—with intrinsic jitter of 8-psec rms at any frequency and has 13 standard functions, modulation capabilities to 10 MHz, and more than 80 measurement types. It also has differential output and high-voltage output amplifiers to test state-of-the-art devices. The 81150A is available in one- and two-channel versions; prices start at $8900.