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We test-drove the low-end AFG3022 model, which is visually identical to the AFG3252 pictured here. It can generate sinewaves at up to 25MHz and pulse/ square/arbitrary waveforms to 12.5MHz. The arbitrary waveform sample rate is 250MS/s, with internal memory space for four 64kbyte waveforms. Tektronix AFG3000 Series Arbitrary/Function Generators Tektronix has just announced a new range of arbitrary/function generators. Dubbed the AFG3000 Series, the line-up includes six models, ranging from a basic single-channel model to dualchannel models with high bandwidths and fast sample rates. All instruments can generate function (sine, ramp, etc), pulse and arbitrary waveforms and are backed by a stable, low-drift (±1ppm per year) timebase. By PETER SMITH At the bottom end of the range, the AFG3021 can generate sinewaves at up to 25MHz and arbitrary/pulse waveforms to 12.5MHz. The arbitrary waveform sample rate is 250MS/s, with the ability to store four 64kb waveforms on-board. The other major difference with this lower-cost model is that it includes a monochrome rather than colour LCD. The AFG3252 dual-channel model tops the range, with 240MHz sinewave generation and a 120MHz arbitrary/ pulse waveform capability. Naturally, it supports a higher sampling rate of 2GS/s and has enough memory for four 128kb waveforms. All models boast a frequency resolu14  Silicon Chip tion of 1mHz (12 digits) and a vertical resolution of 14 bits. Other important features across the series include amplitude, phase and frequency-modulated signal generation, as well as linear/log sweeps and bursts. Also of note is the pulse generator’s independently programmable rise and fall times – a feature previously unavailable at this price range, according to Tektronix. The ability to independently program waveform and frequency settings for each channel on dual-channel models highlights the flexibility of these instruments. Independent channel control has allowed Tek engineers to add other niceties too – like the ability to tweak phase relationship between channels! It all stacks up To capitalise on bench space, these new instruments can be stacked along with Tek’s TDS1000, TDS2000 and TDS3000 series oscilloscopes, thanks to the now familiar “shoe box” form factor. We reported on the latter two series in the July 2001 and July 2002 issues and remain impressed with Tek’s lightweight, portable instrument designs. Unlike the ’scopes, the AFG3000 series don’t include floppy drives. Instead, they feature an up-front USB socket that accepts standard flash siliconchip.com.au memory drives. This obviously makes it very easy to save and exchange waveform suites and instrument set-ups. Other similarities with Tek’s oscilloscopes are immediately apparent. All models feature a large 5.6-inch LCD, which together with the relatively simple front-panel interface and on-screen menus make these models very easy to use. One particularly nice feature is the ability to see a graphical simulation of the generated waveform on-screen, in many cases eliminating the need to monitor the output with a scope. Waveform editing & creation Generating any of the 12 standard waveform shapes is straightforward and can be achieved in seconds with a few keystrokes. However, using the arbitrary waveform generator to create your own wave shapes can be a different matter. With the aid of “soft” keys, the numeric keypad and the rotary dial, it’s possible to define all of the points necessary for creating a new waveform, using the built-in “edit” memory as your workspace. The result can be viewed on-screen, saved in one of the four memory slots and transferred to a USB memory stick for later retrieval. However, this method of creation could be extremely tedious, particularly if the task involves replication of a complex real-world analog signal. The answer is to install Tek’s ArbExpress software on a PC and use that to create all your waveforms. This highly useful application allows you to create and edit waveforms in a variety of ways. For example, you can manually create a waveform using the straightforward point-and-click interface or define it mathematically and have ArbExpress generate a representative plot. This is significantly easier than creating the waveform on the instrument itself. For direct waveform replication though, there’s an even easier way – just acquire or import it from any of Tek’s digital scopes! Alternatively, you can transfer a waveform directly out of MatLab (no conversion is necessary), or import it in CSV format from a variety of sources. What a timesaver! ArbExpress 2.0 software runs on Windows PCs and makes creating your own waveforms as painless as possible. New waveforms can be created manually, defined mathematically or imported from a Tektronix digital ’scope. MatLab users can also bring in their creations without intermediate conversion. instrument USB connection. A second USB connector is located at the rear of the instrument for this purpose. The AFG3000 series can also be controlled remotely via USB, GPIB and LAN interfaces. In fact, ArbExpress includes a rudimentary control interface. Note, however, that the latter two interface types are not present on the lower-cost AFG3021 and AFG3022 models. ArbExpress 2.0 is a standard part of the instrument package and is included on CD-ROM with all models. Bottom line The AFG3000 Series arbitrary/function generators are easy to operate and offer excellent performance for their price. Tektronix claim that for applications requiring signals with sampling rates of 1GS/s or more, the AFG3000 Series can save purchasers up to 75% of the cost when compared to many other high-performance products. The higher bandwidth models in the series will no doubt appeal to designers developing high-performance computing, communications and video equipment. The more basic models will attract users in educational institutions, as well as designers of consumer electronics and medical and automotive systems. The Tektronix AFG3022 costs $3863 (including GST), while the other models that make up the 3000 Series cost from $2546-$12,160. For further information, contact NewTek Instruments Pty Ltd, 3 Byfield St, North Ryde 2113 – phone (02) 9888 0100. Or go to SC www.newtekinstruments.com Right: plug-in USB flash drives allow instant loading and saving of waveform data and set-ups. A second USB slot is also located at the rear of the instrument, for connection to a PC. Networking & remote control Once created, waveforms can be transferred to the instrument via a USB memory stick or uploaded from within ArbExpress using a direct PC-tosiliconchip.com.au January 2006  15