SNAP ADC Calibration

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You want to collect data? Then you probably want a functioning ADC. Say no more!

adc16_init.py and adc16.py scripts will satisfy all your analog to digital conversion needs. They are available in here.

Provided your chip is is HMCAD1511 and you’re using a SNAP board, naturally.

Term.png

You’re sitting at your computer: palms sweaty, heart beat elevated, mouth getting drier by the second. How in the world do you use these mysterious scripts that you’re pretty sure are a product of powerful witch craft?

Python argsparse is here to help. Try:


python adc16_init.py -h

Termhelp.png

This shows a usage example along with some sweet options. Note that the demux mode option is not really optional. Knowing which demux mode you need to use is quiet critical to the proper ADC calibration.

Important calibration notes regarding demux modes: Selecting the right demux mode is vital to calibration success. Say you’re about to calibrate the ADC chips and just have the clocking signal plugged in, what demux mode should you pass to the adc16_init.py script?

Demuxtable.png


  • This value is specified as 1GHz in the ADC (HMCAD1511) data sheet but we noticed that chip B malfunctions at that rate but will work fine at a lower clock speed.

Operation Step-by-step instruction:

  1. Plug in the clock signal. Set the clock speed according to the demux mode table above. Clock is inputted into the 4th SMA connector from the transceiver hub.


SNAPclk1.jpg


  1. go to adc16 script directory.
  2. run python nameofyourhost nameofyourboffile -d yourdemuxmode [other options..]
  3. If you get encouraging messages at the end of calibration then it’s time to celebrate and crack open that Russian Imperial Stout.
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