With both current and voltage feedback operational amplifiers (op amps) available to the system designer, how do you select which device to use? This two-part article discusses applications most suited to each type of op amp, and why certain applications are unsuitable for one or the other type of amplifier. Widely-used circuits are shown with example designs. The emerging fully differential amplifier type of amplifier (a special case of a voltage feedback device) is also shown along with several suitable applications. Part 1 reviews the internal differences between the two types of op amps and presents some key applications most suitable to voltage feedback type devices.