Brochure

Backgrounder
The benefits of greater DSO bandwidth are not limited to viewing signal edges. Ground bounce,
noise, crosstalk, and many other aberrations can be observed more readily—and overlooked
less often—when a high-bandwidth instrument is used.
The higher the bandwidth, the more accurate the reproduction of your signal, as illustrated with
a signal captured by the TDS2000 Series at 60 MHz and 200 MHz bandwidth levels.
CONDITIONAL TRIGGERING PINPOINTS TIMING PROBLEMS
An important but sometimes misunderstood laborsaving tool in every DSO is its selection of
triggering conditions. When a DSO triggers, it is proof that the conditions you specified have
been met. This simple fact, as much as the resulting waveform display, makes conditional
triggering an essential tool for embedded system troubleshooting. Many people already use
noise reject (which often increases trigger hysteresis) to limit runt pulses, and the various
bandwidth limits to select out desired signals.
One of the most versatile triggering features, the pulse width trigger, has recently migrated from
high-end lab instruments into low-cost DSOs, such as the TDS2000 Series. With this setting,
the oscilloscope triggers when the incoming signal’s pulse width is:
< (LESS THAN) the specified time
> (GREATER THAN) the specified time
= (EQUAL TO) the specified time (within a nominal tolerance)
≠ (NOT EQUAL TO) the specified time (within a nominal tolerance)
The LESS THAN pulse width trigger is one of the fastest ways to find suspected transient
pulses on a bus or device output. Brief full-amplitude transients caused by crosstalk or timing
issues can cause intermittent problems when they momentarily strobe a device’s Output Enable
or Chip Select input, for example. This may cause the device to send its data to the bus “out of
turn,” with unpredictable results. The LESS THAN trigger detects pulses shorter than a user-
specified width and causes the oscilloscope to acquire the signals present at all connected
probe inputs. By this means, it is possible to capture not only the transient itself, but also (if four
oscilloscope channels are used) any resulting activity on the Output Enable line, the data bus,
and so on.
3 40W-18247-0