Designing of High Voltage Class Damplifierwith Power Feedback for Piezoelectric Loads

In this paper a Class-D amplifier is proposed to drive piezoelectric loads considering efficiency, linearity and electromagnetic interference issues. The proposed class-D amplifier is based on pulse-width-modulation (PWM) battery-fed. The amplifier not only supplies high voltage power but also utilizes dc-to-dc chopper to make electric isolation and reduce the output distortion. Using isolation dc chopper, causes amplifier isolation from the battery and in turn leads the circuits to be secured from the output distortions. The proposed class-D amplifier consists of a close-loop H-bridge ac-to-dc converter to improve the gain and reduce the output distortion. The amplifier is linear and the achieved output voltage THD is less than 0.9% by a band-pass filter. The proposed amplifier is analyzed in different modes precisely and its operation is simulated. Main features are electric isolation from the source, linearity, fast response and sufficient band-pass.