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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
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