pinku said:
Is there any simple method to generate a sine wave of frequency 1MHZ by
using LM324
op-amp/by using filters /by using oscillators (please mention the
specifications and schematic diagrams).
please reply me with in 24 hours(urgent).
The answer is no, whch isn't going to help get your homework done.
If you look at the data sheet for the LM324
http://www.national.com/ds/LM/LM124.pdf
and check out page 7, you will see that amplfier runs out of small
signal gain at about 1MHz (top of page, left hand side) while the large
signal output swing falls below 1V at 100kHz.
If your instructor was silly enough to specify an LM324 as the op amp
to use for this job you've got an easy answer to the question.
Otherwise you are going to have to start out by finding a faster
amplifier.
How much distortion in the sine wave can you accept? What sort of
amplitude do you need? Does the frequency have to be exactly 1MHz? If
so, tell us what sort of range frequencies would count as "exact" -
+/-10Hz?
How stable do amplittude and frequency have to be?
In the meantime, googling on Wien bridge and phase-shift oscillators
might give you some ideas.
http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/oscphas.html
http://www.ecircuitcenter.com/Circuits/opwien/opwien.htm
The circuit given above for the Wien bridge will produce a rather
distorted sine wave - there are better versions of the Wien bridge, See
Jim Williams Linear Technology application note AN43 on bridge circuits
- the first half of the application notes talks about Wheatstone
bridges, but the second half gets onto Wien bridges.