Buffer amplifiers have unity gain. They are used to match impedances between two devices, or as isolators. Buffer amplifiers carry performance specifications such as operating temperature, input offset voltage, supply voltage, supply current and bandwidth. Slew rate and bandwidth are also important considerations. With buffer amplifiers, slew rate at which the output voltage changes in response to a step input. Bandwidth refers to the ability of a buffer amplifier to provide a maximum output voltage swing with increasing frequency. At some frequency, the output will become the slew rate and begin to degrade.