Multisim and Ultiboard

cancel
Showing results for 
Search instead for 
Did you mean: 

Discrepancy between Frequency shown by probe and FFT

I'm trying to get this circuit to oscillate at 13.56 MHz:

ehuang3190_1-1625700310458.png

However this is the frequency of the probe and the frequency counter:

ehuang3190_3-1625700472325.png

Same applies when drawing cursors:

ehuang3190_4-1625700531078.png

 

I tried running an FFT on the sine wave, but it peaks at whatever I set the fundamental frequency to in the setup:

ehuang3190_5-1625700595150.png

ehuang3190_6-1625700621550.png

Replacing my modified 13.56 MHz crystal with a 15 MHz one provided by Multisim yielded this result, with a reported frequency slightly below the supposed 15 MHz.

ehuang3190_7-1625701000637.png

 

Additionally while waiting for the crystal to stabilize, the probe and frequency counter gave out different frequencies:

ehuang3190_2-1625700395142.png

 

I feel like I'm not using something properly, or I don't understand how some of these work. Any ideas? Thank you!

 

 

0 Kudos
Message 1 of 2
(1,209 Views)

Дорогой друг!
Я протестировал все кварцы из Мультисима-14.2. Почти все- врут. Надо заходить в "свойства" и подправлять модели, путём изменения ёмкости, или индуктивности. Думаю, разберётесь по картинкам

0 Kudos
Message 2 of 2
(1,169 Views)