Amplifying Function generator output (Square wave at 100kHz)

[ozi125_2]

Hi All,
I am trying to amplify a function generator output (10V pk-pk square wave at 100kHz) to 30V pk-pk . I constructed a circuit using OPA452 in inverting configuration with a gain of 3 but I get clipping around 25V pk-pk even though the opamp is rated for 80V pk-pk. Also the rise time and fall time are very slow at 100kHz it's almost like a triangle. The slew rate for the opamp is ~8V/us. I am wondering if there is a way to amplify this signal with a pretty fast rise and fall time.

Thanks in advance.

 

[FoxyRick]

At 100KHz, the period is 10µs. If the slew of the OPA452 is about 7.5V/µs, then to swing 30V needs 4µs. To swing back again needs another 4µs.

So, out of your 10µs, 8µs is spend slewing up and down.

---------- Post added at 18:13 ---------- Previous post was at 18:02 ----------

The OPA445 is a bit faster at (typical) 15V/us.

 

[ozi125_2]

I have been looking into other options. I found this op-amp with a max slew rate of 350V/us "http://www0.cirrus.com/en/pubs/proDatasheet/PA343U_A.pdf"

What I am wondering is that the compensation capacitor makes the large signal gain quite low at 100kHz. Why would I need compensation capacitor for such an application?

Thanks,

 

[goldsmith]

Dear ozi125_2
Hi
Has your frequency any variation ? for example between 0.1 HZ up to 100KHZ , or perhaps it's frequency is constant ?
If it's frequency is constant there are many cheaper and easier ways , available why you decided to use an opamp ?
Best Wishes
Goldsmith

 

[ozi125_2]

Dear ozi125_2
Hi
Has your frequency any variation ? for example between 0.1 HZ up to 100KHZ , or perhaps it's frequency is constant ?
If it's frequency is constant there are many cheaper and easier ways , available why you decided to use an opamp ?
Best Wishes
Goldsmith

Yes the frequency is constant at 100kHz. I thought op-amp would be cheaper and easier but I am eager to hear what the other options are for constant frequency.

Thanks in advance.

 

[goldsmith]

Hi again
A push pull amplifier with transformer ! ( that you'll wind it ! ) it can give you your desired voltage simply , and very higher powers ! ( it is one of many ways that you can do ).
Best Wishes
Goldsmith