Datasheet

Features in detail
Higher Waveform Frequencies
The TG501xA out-performs other generators in its price
range by offering both sine and square waves up to
50MHz. The lower cost TG251xA operates to 25MHz.
Exceptional frequency precision
The frequency of these waveforms can be set with up to 14 digits or one
micro hertz of resolution.
The DDS based frequency generation system uses a TCXO timebase
oscillator with a stability of 1ppm.
Waveform quality
The TG501xA and TG251xA generate high purity sine waves with low
harmonic distortion and low phase noise. Square waves have a rise time
of below 8ns (13ns on TG251xA) and low overshoot. Variable symmetry
can be used up to 25MHz.
Triangle and ramp
High quality triangle and variable symmetry ramp waveforms are
available up to 1MHz (TG501xA) or 500kHz (TG251xA).
These waveforms are also available at higher frequencies via the arbitrary
function but without symmetry adjustment and with reduced waveform
quality as the frequency increases.
VLF generation
The high resolution of the DDS system means that very low frequencies
can be set. For example, a frequency of around 1mHz could be set with a
resolution of 0.1% and a stability of 1ppm.
Full Pulse Generator capabilities
Both models incorporate a pulse generator mode which
provides wide range pulse width and delay independent
of period. Rise and fall times (edge speeds) are also
fully variable.
Wide-range repetition rate
On the TG501xA, the pulse period can be set between 80ns and 2000
secs. (0.5mHz to 12.5MHz) with a resolution of 14 digits or 1µHz. On the
TG251xA, the minimum pulse period is 160ns (6.25MHz).
Fully variable pulse width and delay
Pulse width and pulse delay can be independently set to a resolution of
10ns. Minimum pulse width is 20ns and duty cycles can be as low as one
in two billion.
Note that display screens on this page are shown at around 80% of actual size.
Independently variable rise and fall
The generators offer very fast edge speeds of better than 8ns on the
TG501xA or 13ns on the TG251xA, but the edges can be slowed down to
simulate slower pulses.
Rise and fall times are independently variable in the range 5ns to 40us
(10ns to 40µs on the TG251xA), or can be linked so that both edge speeds
are the same.
Trigger, burst and gate
As with all other waveforms, pulses can be triggered from an external
trigger input (or a manual trigger, the internal trigger generator or a Bus
command).
Burst mode creates a burst of between one and a million pulses in
response to each active edge of the trigger.
Gated cause pulses to be generated only when the gate signal is true. The
gate source can be external or internal exactly as the trigger signal.
Arbitrary Waveforms
Both generators offer DDS generated arbitrary
waveforms capability. A number of standard waveforms
are included, and up to four user defined arbitrary
waveforms can be stored in the instrument at any one time.
14 bits, 128k words, 125MS/s
Waveforms have a vertical resolution of 14 bits (16,384 amplitude levels).
Waveforms can be created using between 2 and 131,072 points (128k).
The sampling rate is 125MHz and DDS techniques are used to provide any
repetition rate between 1µHz and 10MHz (TG501xA) or 6MHz (TG251xA)
with up to 14 digits of frequency resolution.
Internal and external waveform storage
Up to four user defined waveforms totalling up to 256k words can be
stored within the permanent internal memory of the instrument.
However, a front mounted USB port enables external Flash memory
storage of up to 1000 waveforms of any size.
This memory stick also provides a quick and convenient method for
transferring waveform files to and from a PC. It can also be used for
storing instrument set-ups.
Pre-built complex waveforms
Commonly used complex waveforms are provided both
built-in to the instrument and for loading into the user
defined waveform space.
These include sin(x)/x, exponential rise and fall,
logarithmic rise and fall, gaussian, lorentz, haversine and cardiac
waveforms.
Waveform creation & editing
Arbitrary waveforms can be created and edited using the simple tools
built into the instrument. However, complex waveforms require an
external PC based editor.
Both instruments are supplied with Waveform Manager Plus for Windows®
which provides the most comprehensive set of waveform tools available
including a mathematical expression editor, freehand drawing, waveform
libraries, and import of waveforms using the Clip Board.
More information is provided on Page 7 of this brochure.
Standard, Pulse and Arbitrary Waveforms