tdeball

Hi, I have a project where I am trying to create a 100Hhz sine or square wave to be used a clock input to a device. I have an Analog Discovery 2 and ADP3250. Both datasheets say they can generate waveforms at 125Mhz, but when I am in the Wavegen tab of Waveforms, I can only get it to go to 31.25Mhz for a sine or square wave. Are these devices capable of of generating a 100Mhz sine or square wave? If so, how? Thanks!

This is a great find. To confirm, the ADP is or is not currently capable of oversampling to 16bits? Is there a known date for the next sw version to be released?

Sounds good. I'm not sure that offset range will be sufficient for the full dynamic range scenario. I also forgot that the circuit change (removing the instrumentation amps) would eliminate 100x gain so the requirement for the full dynamic range measurement would be higher than 14 bit. Ultimately, I think the ADpro (and maybe the AD2) will meet my needs. I will buy the ADpro and keep prototyping to find out. This discussion was extremely helpful and informative. Much appreciated!

Wow Sidney! I really appreciate the responses and amount of info you are providing. I'll back up a step and provide a bit more info about my system. I have a current system that I am updating. My main test circuit produces a 50-100ms pulse (length and magnitude is test dependent and adjustable). The pulse has a 1mV to 40mV portion that rides on top of a relatively large square wave (.5 to 20V) (test dependent). I am keeping it somewhat vague and refraining from using industry key words to prevent this from being easily searchable by our customer. There is a processing section of my test circuit that cancels out the square wave using several variable gain instrumentation amps. The instrumentation amps also scale up the important portion of the signal by 100x. The magnification and cancelling the square wave significantly reduces the data capture (oscilloscope) dynamic range requirement. Two options for updating the system with a modern USB oscope: 1) keep the test and cancelling circuit the same, use a AD2 or ADpro to replace the existing custom oscope board. 2) I am considering using a high end picoscope to accept the full dynamic range of the test. This would eliminate all the instrumentation amps and the square wave cancelling portion would be done by my software. This would greatly simplify my system circuit. The picoscope can be oversampled to 20bits. One thing @reddish said that is very interesting is utilizing the offset functionality of the ADpro. I know the expected voltage band that the square wave will fall. Could I set the offset at any value and use the "low range" to get a higher effective dynamic range? For example, get 14 bits from 2V to 7V for one test and then change the offset and get 14 bits from 6V to 11V for another test? That would be perfect! @reddish also mentioned calibration. My equipment is calibrated annually. How accurate can the offset be calibrated?

Hi @reddish, Great to know about the waveforms application and the API. I only need 1 channel and an external trigger. I am currently working in Python and progressing pretty well through my proof of principle prototype. I am open to changing to C++ if needed depending on the speed performance i get once i start manipulating the buffered data. I can post a new question if needed, but is there a way to get more voltage ranges? There is a pretty big jump between 2V and 50V and this makes the LSB change significant. My signals will be between 0.1V and 5V so when using the AD3250, I will need to be in the "High Range" of +/-50V / 14 bits = 3.3mV resolution. If i could set it to +/-5V instead, my resolution could be 10 times higher.

Hi, I was typing up a new question and decided to search again for the answer and found this thread which is basically identical to my question. This thread has been extremely helpful! I am currently investigating the AD2 and AD3250 for an embedded system. I require at least 1MS/s (ideally faster) for 200ms (minimum buffer size of 200k). Signal is <5V and 12bit resolution is required. If I understand correctly, this discussion rules out the AD2 for my application, but the AD3250 should far exceed my needs. Can someone please confirm? I will be using the SDK and not the waveforms app, does this change anything regarding data capture rate capability?

That did it! The newer version of dwfconstants.py defines 'DwfWindowRectangular'. Thank you!

Hi, I am working through some of the Waveform SDK examples on an Analog Discovery 2. I can get all of the samples in the SDK/samples/py directory to work. Then i progressed to the "WaveForms-SDK-Getting-Started-PY-master" samples. None of these are working due to the error below. Any help would be appreciated! XXX-MacBook-Pro-2:~ XXX$ /usr/bin/python3 /Users/XXX/Downloads/WaveForms-SDK-Getting-Started-PY-master/test_device_info.py Traceback (most recent call last): File "/Users/XXX/Downloads/WaveForms-SDK-Getting-Started-PY-master/test_device_info.py", line 1, in <module> from WF_SDK import device, error # import instruments File "/Users/XXX/Downloads/WaveForms-SDK-Getting-Started-PY-master/WF_SDK/__init__.py", line 15, in <module> from WF_SDK import tools File "/Users/XXX/Downloads/WaveForms-SDK-Getting-Started-PY-master/WF_SDK/tools.py", line 29, in <module> class window: File "/Users/XXX/Downloads/WaveForms-SDK-Getting-Started-PY-master/WF_SDK/tools.py", line 31, in window rectangular = constants.DwfWindowRectangular AttributeError: module 'dwfconstants' has no attribute 'DwfWindowRectangular'