Frequency range is 0.0002 Hz to 20
MHz with a 40-MHz option available.
Resolution measures 5 ns, and jitter less
than 200 ps. The standard output is transistor-
transistor logic (TTL) or adjustable
from 0 to 4 V with a 3-ns rise time typical.
An adjustable high-voltage output option
is also available. Each channel may have
its own input trigger, or all channels can be
triggered simultaneously.
The 575 has a separate delay generator.
It offers fine resolution and accuracy of
delays and widths. Basic resolution is 250 ps with an accuracy to 1 ppm. The rate,
selected by period, is set to a resolution of
10 ns. Separate delay channel triggering
inputs are available, or triggering may be
done on all channels at the same time.
Also, the 575 includes optical outputs
with ST connectors. The output LEDs
operate at 820 and 1310 nm with a rate
to 5 Mbaud. Resolution is 500 ps. Maximum
optical link distance runs 1.5 km.
Up to two optical inputs are also available.
It offers external programmability
through standard RS-232 or USB ports.
An option provides for GPIB or Ethernet
programming interfaces. In addition, onboard
storage helps save setting profiles.
National Instruments LabVIEW drivers
are available as well.
The Tektronix DTG5000 pulse generator
is another data generator (Fig. 10).
Depending on which module is selected
and which modules are used, the generator
can produce pulses and data streams at
speeds to 3.35 Gbits/s on one, eight, 16,
32, 64, or 96 channels. Users also get full
control over all pulse characteristics. Pulse
delay capability is available on each channel
with a 0.2-ps resolution.
The different models deliver pulsegeneration
frequencies from 50 kHz to
750 Mbits/s, 2.7 Gbits/s, or 3.35 Gbits/s.
Typical pulse formats available are NRZ,
RZ, and R1. Pulse width, duty cycle, and
delay are fully variable. Pulse-width resolution
is 5 ps. Random jitter can be added
at less than 3 ps rms. A PRBS PN15 data
pattern capability up to PN23 is available.
Pattern length per channel is 8, 32, or 64
Mbits, depending on the model.
A range of pre-stored patterns is available
as well, such as binary, Gray, Johnson,
or checkerboard codes. For instrument control and data transfer, the DTG5000
has
GPIB and Ethernet interfaces. I/O
ports available include USB, RS-232, RJ45
for 10/100 Ethernet, and VGA out.
Many other types of generators exist for
special testing. For example, video generators
produce the signals for TV and video
testing. Also, noise generators create white
or pink random noise that can be added to
the output of another signal generator to
test noise immunity or performance of
amplifiers or other circuits. Other special
generators can produce the signal to create
jitter in pulse generators or AWGs.