The LeCroy 9420
is a wide bandwidth digital Oscilloscope
suited to a variety of engineering design and test
applications. It is used to capture, analyze, display and
archive electrical waveforms in fields such as analog and
digital engineering, automated test and measurement,
telecommunication and electronics research.
features two 1.00 mega sample/second 8-bit Flash
ADC systems, two 5OK non-volatile memories for waveform
acquisition and storage, and an additional four 50K memories
for waveform processing and temporary storage. High-speed
internal data transfer and processing are performed using a
multi-processor system. The central processor is a powerful
68020 microprocessor which performs computations
and controls the oscilloscope’s operation.
All front-panel knobs and buttons are constantly monitored
by the internal processor, and front-panel setups are
rapidly reconfigured via the unit’s internal 16-bit bus.
Data are quickly processed according to the selected
frontpanel setups, and are transferred to the display memory
for direct waveform display or stored in the 9420’s
The 68020 controls the unit’s GFIB (IEEE-488) remote control
port, as well as the RS-232-C port which is used to directly
to a digital plotter, printer, remote
terminal or other slow-speed device.
ADCs AND MEMORIES
Each of the 9420’s two identical input channels is equipped
with a 00 megasample/second, 8—bit ADC and a 50 kiloword
acquisition memory (see Figure 4). This dual ADC
architecture ensures absolute amplitude and phase
correlation, maximum ADC performance for both single- and
dual-channel acquisition modes, large record lengths and
excellent time resolution.
The 9420’s two 5OK acquisition memories simplify transient
capture by providing very long waveform records that capture
waveforms even when trigger timing or signal speed is
uncertain. In addition, a special expansion facility
magnifies waveforms by up to 1000 times the selected
The 9420 Oscilloscope
is capable of acquiring and storing
repetitive signals at a Random Interleaved Sampling (RIS)
rate of 10 giga-samples/second. RIS is a high-precision,
digitizing technique that enables measurement of repetitive
signals to a bandwidth of 350 MHz with an effective sampling
interval of 100 psec and measurement resolution of 5 psec.
assures precision measurements over its entire
range of operation.
The 9420’s digitally-controlled trigger system offers an
extensive range of trigger capabilities. Front-panel and
menu controls let the user choose the appropriate trigger
function for the signal.
In the standard trigger mode the 9420’s front-panel controls
are used to select and set parameters such as pre- and
post-trigger recording, sequence and roll modes, in addition
to the Auto, Normal and Single (Hold) modes. The trigger
source can be line, external or either of the two inputs.
The coupling is selected from HF, AC, LF REJect, HF REJect
and DC and the slope from positive and negative.
The SMART trigger facility provides a complete range of
sophisticated and versatile trigger features. The following
trigger classes and operational modes are available:
has an automatic calibration facility that ensures
overall vertical accuracy of db 2% of full scale and a
time-base interpolator accuracy of db 20 psec RMS for the
unit’s crystal-controlled time base.
The time base is calibrated each time the 94205s time-base
control is adjusted to a new Time/div setting; vertical gain
and offset calibration take place each time the front-panel
fixed gain control for either Chan 1 or Chan 2 is adjusted
to a new Volts/div setting. Both channels are also
calibrated each time the Bandwidth Limit button is pressed.
In addition, the 9420
performs periodic calibration to
ensure the long term stability at a particular setting.
The 9420’s large 12.5 X 17.5 cm (5 X 7 inches) screen
displays waveforms with high resolution and serves as an
interactive, user-friendly Interface
via a set of
pushbuttons located immediately to the left and right of the
CRT. The Oscilloscope
displays up to four waveforms, while
simultaneously reporting the parameters controlling signal
acquisition. In addition, the screen presents internal
status and measurement results, as well as operational,
measurement, and waveform analysis menus.
A hard copy of the 9420’s screen is available via the unit’s
front-panel screen dump button. Plotting is done in parallel
with normal Oscilloscope