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Siglent SDS1104X-E In-Depth Review
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lordvader88:
Ok thanks

In terms of NAND type memoroy or modern DDR(x) ram, what do these modern scopes use and how much ?
Performa01:
I got a request for another noise demonstration, so here it is.

Ch.1: 20MHz BW-Limit, DC, open input
Ch.2: 20MHz BW-Limit, AC, open input
Ch.3: 20MHz BW-Limit, DC, ext. 50Ohm input termination
Ch.4: 20MHz BW-Limit, AC, ext. 50Ohm input termination


SDS1104X-E Noise TD 20MHz

There are no significant differences and RMS noise is about 29µV on average.

If we really need clean traces, we can use Average acquisition mode. This attenuates any modulation, but doesn’t affect the bandwidth. Since it’s HW-accelerated, the waveform update rate is also nearly the same as in normal acquisition mode.

Here’s an example how just 4 times averaging cleans up the traces very nicely:


SDS1104X-E Noise TD 20MHz AVG4


Finally I can demonstrate the low frequency noise floor (which is always the most critical one) by showing an FFT from DC to 500Hz with ~1Hz frequency step, hence about 3-4Hz RBW with the flat top window:


SDS1104X-E Noise FD 500Hz

FFT trace averaging 16 times to get a clear picture as is common for noise measurements.

EDIT: sorry, I've attached the wrong screenshots originally.

Performa01:
In interleaved mode (full 1GSa/s per channel) the noise is even a tad lower.
Here's another screenshot showing the peak-peak measurement also.


SDS1104X-E Noise TD CH4 20MHz
Performa01:
I got another request for a 150µV low frequency challenge.

Well, this is certainly going to be a problem for any 8bit scope, even if it has a low noise 500µV/div setting.

This is about a 150µVrms sine at 10Hz – the frequency where noise is strongest due to the low frequency path in the input buffer, which consists of a high value resistor network at the input and some FET OpAmp with considerable 1/f noise. Furthermore, this OpAmp has to make up for the attenuation of the resistive input divider and then feeds its output to the summing node of the split path input buffer via another high value resistor.

Here’s the test as requested, with 3.0 bits Eres, which acts as a lowpass filter and won’t help with the 1/f noise. Yet I’ve turned the memory down to 14kpts in order to achieve some 800Hz cutoff frequency and exclude at least the high frequency noise by this.


SDS1104X-E_Sine_150µV_10ms_Eres3_14kpts

Well, the result is certainly anything but pretty.

We get much better results by using Average instead of Eres – here’s an example for 16 times Averaging and deep 1.4Mpts memory:


SDS1104X-E_Sine_150µV_10ms_Avg16_1.4Mpts

Now we get the full bandwidth (well, limited to 5MHz by the 10MSa/s sample rate) and the signal looks reasonably nice.


Just as a comparison, a true 16bit Picoscope 4262 with HiRes to 20bits (not even necessary) handles this much better, even though its highest sensitivity is just 2mV/div (I’ve used zoom in this screenshot):


Pico_4262_Sine_150µV_20ms_HiRes20_2Mpts

kahuna0k:

--- Quote from: Performa01 on March 11, 2018, 12:59:09 am ---The first implementation of the MSO option has become available with firmware 7.6.1.20 and I’ve received the SLA1016 digital probe about a week ago. Unfortunately the Sbus cable was missing and even though the connectors are identical, an HDMI cable cannot replace it. So I have to wait until I get the original one.

Until then, I’ll show some details of the hardware. First the contents of the box (minus the Sbus cable):

--- End quote ---

Did you finally got the SBUS cable and did the review of the SLA1016? I've been unable to find it in the thread. I'm thinking about getting it to be able to trigger on analog. I have a Digital Discovery (https://store.digilentinc.com/digital-discovery-portable-usb-logic-analyzer-and-digital-pattern-generator/) from Digilent that goes up to 800MS/s but is digital only. What's your opinon on the SLA1016?

Thanks!
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