Dear All,


Few years ago while I was learning about 8051 controllers I have refered the book by "Kenneth J. Ayala" (Also listed in 8052's books link).

Unfortunately currently I am not working on 8051's & do not have Ayala for reference, but as much as I recollect there are two types of crystal oscillators described. One of them had shown with two burdan capacitors & other was shown with inbuilt capacitors & its body needs to be connected to ground.

Now after going through these messages I am completely confused as the book says there can be two types of crystal oscillators one which requires the burdan capacitors & one which does not require,

Now when I tried for this (I am working in INDIA & have purchased the crystals from local market, but the part number matches with the KDS crystals which are said to be of type with inbuilt capacitors), my circuit was not working & I found that the clock was available on one of the Clock pins of my controllers (Do not remember 18 or 19) & there was 0V at the other. Then just for a try I connected the 33pF capacitors & the return clock was available on the second pin & my circuit started working.

At that point I just ignored the point by saying, may be the INDIAN market does not give me the reliable components & it is better to always connect the burdan capacitors.

But still I don't know whether the crystal oscillators with in built capacitors really work without burdan capacitors?