Piezoelectric actuators are widely used in precision mechatronic systems, but their capacitive load and high-voltage requirements make efficient, low-distortion driving electronics challenging. This thesis presents the structural design and implementation of a mixed-signal Class-H amplifier intended for piezo applications. This amplifier makes use of an isolated Class-AB amplifier and an isolated Class-D amplifier to achieve low power losses and high charge accuracy. A system-level architecture is developed from actuator requirements and translated into key circuit blocks, including the supply modulation strategy,sensing and feedback paths, and the digital control and isolation interfaces. For this digital control of the amplifier a novel digital circuit calculator and simulator have been build. Experimental results on a prototype hardware platform demonstrate regulated rail tracking, improved efficiency compared to Class-AB operation, and output performance suitable for driving piezoelectric loads. The developments in this prototype allow for further development into Class-H and digital feedback amplifiers.