Re: Weird Amplifier Problem
To my opinion, THS3001 is a rather stable and easy-care OP among the high speed types. If wired uncorrectly, I would rather expect oscillations at several 100 MHz than at 5 MHz and I really wonder how you managed to achieve it.
Something like a completely wrong feedback dimensioning or a very unusual supply decoupling may be an explanation. You should show your simple amplifier circuit for better understanding. I assume, that you understood the basic requirements of current mode OP feedback circuits?
The above quoted datasheet suggestions are a good starting point, but also with less decoupling, the part would be stable, normally. At least if not driving heavy loads.