Sin generator at a freq of 1 MHz, and Vpp of 10-20 volts

[aviaden]

Sin generator

Hi,
I need to build a sin generator at a freq of 1 MHz, and Vpp of 10-20 volts.
I've built a Wein birdge and and used 741 Op Amp. But i got a nice sin only for freq up to 100 KHz. I tried to switch to a AD8042, op amp, that has a better BW, but with no sucsses.

I would appreciate any ideas how to get a nice sinus wave to meet these requirements.

Thanks, Aviad

 

[LvW]

Re: Sin generator

AVIADEN, there are several oscillator circuits - and the WIEN type is certainly not the best, however in any case you need a better opamp.

Minimum requirements:
1) Opamp transit frequency Ft>100*Fo (Fo=osc. frequency)
2) opamp slew rate SR>2Pi*Fo*Umax (Umax=output amplitude).

 

[FvM]

Re: Sin generator

I tried to switch to a AD8042, op amp, that has a better BW, but with no sucsses.

What does "with no success" mean in this regard?
- It didn't work, but you didn't further check why?
- You know, what's the problem, but didn't wan't to tell?

I'm rather sure, that you can build a 1 MHz Wien bridge oscillator wieth AD8041 or 8042 (dual AD8041), at least the OP is fast enough.
But it's limited to +/- 5V supply, so it won't fulfill your level requirement.

 

[aviaden]

Re: Sin generator

Ok. Thanks for the information about the op amp.
Can you please send me a circuit of a good oscillator? or tell me what the scillator name is? or any reference to this circuit on the web...

Thank's alot, Aviad.

 

[LvW]

Re: Sin generator

Can you please send me a circuit of a good oscillator?

What is a good car? Do you have an answer?
You should tell us something about your requirements:
*Tunability?
*Frequency stability?
*maximum THD?
*amplitude exactness and stability?
*number of allowed opamps
*Did I forgot something??

 

[vfone]

Re: Sin generator

https://www.jensign.com/wien/index.html
https://www.edn.com/archives/1995/060895/12di5.htm

 

[nashwan]

Re: Sin generator

hi aviaden

see that wein-bridge use fast op amp lm318 to get 1mega hz and high

voltage swing

 

[aviaden]

Sin generator

Thank you very much