I need to built a discrete op amp in a package doesn't exceed 3" on any side. Please help????

Question

I need to built a discrete op amp in a package doesn't exceed 3" on any side. Please help????

Answer 1

Shouldn't be a problem.  You haven't said what the specification of the opamp has to be, but you can build a discrete transistor implementation of a basic opamp with maybe 10-20 transistors and the same number of resistors.  That should fit very easily on a circuit board less than 3" on a side.