current to voltage converter

This question has occupied the back of my mind since you posted it...my friend told me that an OPAMP is used as an inverting amplifier in a I-V converter(for DC). So the fact that the opamp contains transistors in its internal circuit which is a current operated device(Ic= βIb) makes it an ideal device to give an o/p in form of current or vice-versa...also this explanation os valid for DC only...as opamp doesn't necessarily work in AC as it is bandlimited