Optimized Parallel Hybrid Amplifier for Print-Head Piezoelectric Actuators with Trapezoidal Waveforms

Most of the drivers used to control high-frequency print-head piezoelectric actuators are based on linear technology (e.g., Class AB amplifiers) which dissipate a large amount of power for this specific application. This choice is given by the necessary of very precise tracking and large bandwidth for the closed-loop voltage control of the piezoelectric load. This work highlights the critical issues of pure Class D amplifiers and hybrid (switching and linear) solutions. Then a new hybrid power amplifier topology is proposed analyzing its advantages and drawbacks for these kind of piezoelectric loads reducing energy consumption. First of all, the performance of the proposed solution is verified by simulations in LTspice environment. Experimental results showed the effectiveness of the proposed solution potentially paving the way to a larger adoption of this topology for high-frequency piezoelectric actuators. The proposed solution is patent pending.