High-performance sampling system with 1.2 GSa/s sampling rate and 16-bit vertical resolution.
Innovative TrueArb technology, based on a point-by-point architecture, supports any 8 pts ~ 8 Mpts Arb waveform with a sampling rate in range of 1 uSa/s ~ 75 MSa/s.
Where does the limitation of 75 MSa/s come from, while it uses a sampling system with 1.2 GSa/s?
For which signals does it use 1.2 GSa/s? And for which does it use less?
Why you would want to use a variable sampling rate that goes down to 1 uSa/s?
Isn't it better to just always use the highest available sampling rate for best results?
Or is it because of memory limitations, when you want to store longer periods?
But then again, isn't 1 uSa/s a bit on the low side?
Siglent tends to combine random good-sounding specs into a single passage, making it hard to figure out where they all come from. Here are partial answers from my personal notes:
16-BIT RESOLUTION AND 1.2GS/s:
These apply to the DDS (Direct Digital Synthesis) mode of generating arbitrary waveforms.
IN DDS mode the unit pulls 14-bit samples from memory at the rate of 300 million samples per second, then between every two adjacent samples it inserts three interpolated samples that it creates on the fly, resulting in four 16-bit values OUT for every one 14-bit sample IN. The resulting sample stream is sent to the digital-to-analog converter at the rate of 1.2 gigasamples per second (four times the rate at which samples are pulled from memory). This allows the generator to output much cleaner waveforms. Note that no interpolation is done between the first and last sample if the generator is set to loop the sample set.
75Ms/s, 1uS/s:
These apply to the TrueArb mode of generating arbitrary waveforms.
In TrueArb mode the unit will draw samples from memory at a variable rate from 1 sample per 1 million seconds to 75 million samples per second and deliver them (with interpolation?) to the DAC.
Note that the unit will only let you set a "frequency" of up to 4.577,637kHz. But frequency of what? If you divide 75M by 4.6k you get 16,384. So apparently when you set the frequency you are telling the unit how fast to cycle through 16,384 samples.
So what happens if you have more than 16K samples in your sample set? I don't know.