CRYSTAL OSCILLATOR


Dear Forum Members, Thanks.


Dear Raghu,

" Are the direct crystal oscillators available. Where in it has four pins two for DC supply two pins to give direct clock
frequency?.

Now that you know how to make it why not package it yourself ? To the best of knowledge such readymade oscillatora are not available in India.

Raghu "


I have a reason for that to ask. I design PLD/CPLD VLSI circuits embedded with microcontrollers. But thes PLD/CPLD chips
do not have internal oscillator circuit to enable you to connect only the crystal. These CPLD devices need to be supplied with
clock frequencies. (For eg I have a ATMEL CPLD development kit which uses 2MHZ oscillator four pin make CANDOR - I do not know
whether I get in India??). For the reasons of uncertainity of oscillators in the following posts, I would like to use
direct crystal oscillators.



Dear Jacob Boyce, Kai , eric malund & Rob,


(a) I had previous experiences of the crystal oscillator cicuit using invertors. It never used to work with
74HCT04 ( I tried Phillips Make) & I got fed up as I designed my target board and assembled. It took quite some
efforts to realise I need 7404 or 74LS04. That's the precise reason why I want to choose direct crystal oscillators
for my high speed CPLD designs.