A high-performance operational transconductance amplifier (OTA) is proposed. In order to increase DC gain, gain bandwidth, and the slew rate under low standby quiescent current, the proposed OTA has the dynamic output current scaling and class AB operation. Under the condition of 250µA quiescent current and a 30pF load capacitance with a step voltage from 1.2 to 1.5V at a rise time of 1nsec in a unit gain configuration, HSPICE simulation results are presented to show a higher DC gain, gain bandwidth and slew rate than conventional OTAs.