Tektronix Applications Expert

You can find it on our web site at https://www.tek.com/en/oscilloscope/tds3000-manual/tds3000c-series

Take a look at our Datasheet to see the current options for DDR5: https://www.tek.com/en/datasheet/memory-interface-electrical-verification-and-debug-ddr5---system-level-transmitter-tests-datasheet. Here is an additional application note: https://download.tek.com/document/DDR5_Measurement_Challenges_WP_55W-7386.pdf.

The AFG31000s has an accuracy of ± (1% of setting +1 mVpp), so a 50mV signal would have roughly ±1.5mV of noise when producing a 50mVpp. The instrument’s input and output connectors are also floating inputs and outputs, and maximum rated voltage between the chassis ground and common ground is 42 Vpp (DC + peak AC), which is above your required 25V. This information is found on page 3 of the AFG31000 user manual. Because of these two features, the AFG31000 could be great fit for your application.

AFG31000 Product Page: https://www.tek.com/en/products/signal-generators/arbitrary-function-generator/afg31000#

Tektronix/Keithley typically do not recommend floating an instrument unless necessary, as it can be dangerous if proper precautions are not taken. Before floating an instrument, it is important to understand where all connections lead to and what circuits are energized. They are multiple ways that the AFG could be floated, but the most straight forward is to simply connect the AFG and power supply in series. Most power supplies (PS) utilizes banana jack connections, and most AFGs use a BNC connection. In order to float the AFG, you will need to connect the PS positive terminal to the AFG negative terminal of the male BNC connector. This will require some type of BNC breakout adapter. I have attached an image of a related adapter below. Then connect the AFG positive terminal to the device under test (DUT) , and finally connect the output/ground of the DUT to the PS negative terminal.
BNC Adapter - Male to Double Binding Post

Tektronix actually has an Application Note that discusses floating measurements. This document is more oriented towards oscilloscope use, but you may find concepts and tips within the document helpful.
Fundamentals of Floating Measurements and Isolated Input Oscilloscopes: https://download.tek.com/document/3AW_19134_2_MR_Letter.pdf

dBV was the implementation on the TDS3000 series. I've verified the 5 series FFT and SpectrumVu readings are dBm. What can be off is when using 1 Mohm channel impedance or a probe. Our dBm calculation assumed load (50 ohms) doesn't change. External loading is assumed in these cases.

This is easy to check with a sine (pure tone). The single peak in the FFT should match the Vrms measurement. I measured 87.32 mVrms on my sine. Across 50 ohms this is 152.5 mW or -8.17 dBm. My FFT reading was within a dB of this.

When you have multiple peaks, it is harder to match to the Vrms measurement. You can get close by taking the majority peaks, convert to Watts to sum, then calculate Vrms. My measurement was 118.4 mVrms.

Are you familiar with SpectrumVu? This is a digital down conversion within our 5 series acquisition hardware that generates baseband IQ. The 5 series then analyzes baseband IQ the same way a spectrum analyzer would. Additionally, SpectrumVu and analog acquisitions can be enabled at the same time. The only cost is halving the max sample rate. Since you are well bellow the maximum sample rate, you have headroom to turn it on. I can think of three key benefits of SpectrumVu;

-independent analog and spectrum displays letting you optimize each. With traditional FFTs, there is usually a tradeoff between optimizing the time-domain display or the frequency-domain display.
-automatic markers that annotate peak frequency and power.
- use of a chirp z-transform to make SpectrumVu more accommodating to various RBW/record-lengths. (FFTs are constrained to powers of 2 vector lengths. you only have indirect control of FFT RBW via record length. FFT peaks can vary almost 1 dBm based on optimum or sub-optimum record lengths.)

I recommend putting the scope on the internet for longer than 1 hour.

Unfortunately the MDO3 Series is not supported by the data logger in KickStart. For datalogging on a MDO3 Series I would recommend using TekScope Utility instead. It features data logging and a list of additional features, you can find a link to it below.
Please note that TekScope and TekScope Utility are separate software packages. TekScope is official Tektronix software, but is not ideal for your use case
https://forum.tek.com/viewtopic.php?t=140451&__cf_chl_jschl_tk__=Ij829Jr3q9Dus1kVgbVaPbmFatMzpKAZHqrnBQNU2js-1642805988-0-gaNycGzNDr0

It sounds like you're already familiar with OpenChoice, but the other free option that comes with the scopes is e*Scope (Instructions on page 24: https://download.tek.com/manual/071212104web.pdf). Alternatively there is a free tool called TekScope Utility made by one of our engineers in order to transfer data from scopes: https://forum.tek.com/viewtopic.php?t=140451

To better capture your signal, you can set the horizontal mode to manual and change the sample rate, scale, and record length to get a clear image of your whole signal. I have attached an image showing an example of a setup that might work for you. As you can see in the Horizontal badge, this setup gives you 6s on the screen. I also have set the trigger point all the way to the left side so that you will only see the response data. Let me know if you have any questions about this setup.

We support external instruments in ACS and ACS Basic but we do not have specific drivers or software to control and use the 590/595.

Neither of these instruments are designed for direct CV measurements.
The best recommendation would be using the 4200A-SCS with CVU.