This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
As pic below ,I use an external 32.768khz crystal。but when i measure the xosc1 pin, the scope is below ,there is a drop on the scope,why?
Then i change another crystal ,change new 20pf load cap.even i change another tm4c129 ,i find the scope on XOSC1 is good
but the scope on xosc0 is not good as below
you can see the Inconsistent amplitude,w'hy? can somebody smart answer me quickly? I AM SO HURRIED!
as pic above ,the two caps are on bottom layer。there is no other high speed signal around the crystal ,there is only a reset signal and a vbat power signal 。so i don't know why?
the probe i use as the pic below
there is another doubt I find when i set the probe 10x ,as pic below ,i can detect the signal 。
but when i use 1x, whatever i do,i can't detect the scope,as pic below.
When I set the probe 1M Ω ,I can detect the scope ,see pic below
but When I set the probe 50 Ω ,I can not detect the scope ,see pic below
Hello,
user4973896 said:so i want to know is there a standard that specify the bandwidth when test the 32.768k scope?
I am not aware of any such standard, but I am not an expert with crystals.
Honestly this thread as a whole is a bit difficult for us device experts to help with as it isn't clear what is causing the issue and there are doubts that the scope probe used is adding capacitance which is affecting the measurements.
Have you tried reaching out to the crystal manufacturer to request their comments on your measurement techniques as well as the issue you are seeing? They might be able to very quickly resolve your issue in comparison.