With the increasing use of current-feedback amplifiers, the Diamond Structure has come to play a key role in today’s analog circuit technology. Two new macro elements that function in this structure are the Diamond Transistor and its abridged version, the Diamond Buffer. These elements can be used for both voltage and current control of analog signals up to several 100MHz. The OPA660 combines both of these elements in one package. Starting with a discussion of the technical process requirements for complementary-bipolar circuit technology, we would like to focus on the basic and functional circuits of the Diamond Transistor and Buffer. These circuits can be used in areas ranging from video signal processing and pulse processing in measurement technology to interface modules in fiber optic technology.