unipolar output problems

[saurabh17g]

I am using AD 9833 to generate sinewave. The output of this IC is 0.6V(p). So its a sinewave whose mean is 0.3V and signal goes from 0 to 0.6 V instead of -0.3V to 0.3V
I am planning to ampllify this signal using an opamp. Operating frequency upto 5MHz.
So, I need a unipolar opamp. Please give me suggestions.

 

[Nigel Goodwin]

You're making this FAR more complicated than it is - if you feed the sinewave through a capacitor it removes the DC offset anyway.

 

[saurabh17g]

I tried puttting a capacitor at the output. But as I want output at 5MHz, the capacitor(100Uf) attenuates the frequency above 10KHz. So we need an opamp with single polarity.

 

[Nigel Goodwin]

I tried puttting a capacitor at the output. But as I want output at 5MHz, the capacitor(100Uf) attenuates the frequency above 10KHz. So we need an opamp with single polarity.

No you don't - why would you try and use a 100uF for 5MHz?.

There's really no such thing as a 'unipolar' opamp anyway - almost all opamps work on either single or split supplies.

 

[mneary]

I tried puttting a capacitor at the output. But as I want output at 5MHz, the capacitor(100Uf) attenuates the frequency above 10KHz. So we need an opamp with single polarity.

You should try a different capacitor. Like maybe a 10nF (0.01µF). I think in your application a ceramic cap would do the job.