A three-level PWM switching power amplifier with a current-loop is developed. The static and dynamic characteristics,
such as static transfer characteristic, step response, frequency response and current ripple, are simulated and measured. It is shown that the three-level power amplifier has good static and dynamic characteristics and is better for the AMB than the two-level power amplifier because the current ripple of the three-level power amplifier is smaller than the two-level power amplifier and independent with the DC supply voltage.