PXIE-5442 Datasheet, PDF (3/6 Pages) National Instruments Corporation – 100 MS/s, 16-Bit Arbitrary Waveform Generator with Onboard Signal Processing

100 MS/s, 16-Bit Arbitrary Waveform Generator with Onboard Signal Processing
interpolation to increase the effective sample rate, relocating the
reconstruction images to higher frequencies.
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Frequency (MHz)
Figure 3. Using a combination of digital interpolation and analog filtering, the
NI PXIe-5442 greatly reduces the DAC reconstruction images as shown for the 10 MHz
sine signal generated at 100 MS/s using 4X interpolation for a 400 MS/s effective
sampling rate. (The noise floor is limited by the measurement device.)
By doing so, the required analog filter cutoff frequency is increased,
which lessens the filter’s distortion effects. With the combination of
digital interpolation and analog filtering, the NI PXIe-5442 has excellent
passband flatness and improved image rejection, ensuring a low-
distortion output signal.
For sharp waveforms, such as square waves and pulses, you can
disable interpolation and analog filtering to produce fast rise/fall times
and low pulse aberration (overshoot, undershoot, and so on).
Waveform Sequencing and Triggering
You also can program the NI PXIe-5442 to sequence and loop a set of
waveforms. You can choose from several methods to advance through
the sequence of waveforms. In some cases, you know the duration of
each waveform in advance, so you can program the generator to loop
each waveform a specified number of times. When you do not know
the duration before the start of generation, you can use a hardware or
software trigger to advance the generator to the next waveform in the
sequence. The NI PXIe-5442 implements advanced triggering behavior
with four trigger modes: single, continuous, burst, and stepped. For a
detailed discussion of these modes, please consult the
NI Signal Generators Help Guide available at ni.com/manuals.
NI SMC-based generators have the unique capability to store multiple
sequences and their associated waveforms in the generator’s onboard
memory (see Figure 4). In automated test applications involving multiple
tests, each requiring a different waveform sequence, you can download
all of the sequences and waveforms once at the beginning of the test
cycle and store them in the generator’s memory for the entire session.
By downloading all required waveforms and sequences once to an
SMC-based generator instead of repeatedly reloading them for each
test, you save time and improve throughput.
Timing and Synchronization
Using NI T-Clock (TClk) synchronization technology, you can synchronize
multiple NI PXIe-5442 modules for applications requiring a greater
number of channels, such as I/Q signal generation or multiple IF
generation for MIMO systems. Because it is built into the SMC, TClk can
synchronize the NI PXIe-5442 with SMC-based high-speed digitizers and
digital waveform generators and analyzers for tight correlation of analog
and digital stimulus and response. Using onboard calibration
measurements and compensation, TClk can automatically synchronize
any combination of SMC-based modules with less than 500 ps module-
to-module skew. Greatly improved from traditional synchronization
methods, the skew between modules does not increase as the number of
modules increases. To achieve even better performance, you can use a
high-bandwidth oscilloscope to precisely measure the module-to-module
skew. With the oscilloscope measurement for calibration information,
TClk can achieve <20 ps module-to-module skew (see Figure 5).
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Figure 4. NI SMC-based arbitrary waveform generators increase test throughput by
storing all the waveforms and sequences required for a set of tests in onboard memory.
Figure 5. Using SMC TClk synchronization, multiple NI PXIe-5442 modules can achieve
<20 ps channel-to-channel skew.
The NI PXIe-5442 sample clock has three modes: Divide-by-N,
High-Resolution, and External. The direct digital synthesis (DDS)-based
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