A Multicell Linear Power Amplifier for Driving Piezoelectric Loads

A multicell amplifier is developed by connecting floating signal modules in series to drive piezoelectric devices. The amplifier generates a high voltage gain by summing the individual module gains. The bandwidth equals that of a single module. The multicell amplifier provides a means of achieving high power and can divide the total power dissipation among the modules, because each module delivers the same output voltage and current. A prototype circuit that consists of six floating signal modules exhibits precise linear operation over a wide range of input frequencies and capacitive loads. The circuit provides a $\pm$ 200-V output swing with a corner frequency of around 100 kHz at a driving capacitive load of 0.1 $\mu\hbox{F}$. The slew rate is as high as 115 $\hbox{V}/\mu\hbox{s}$, and the maximum output current is $\pm$2.6 A. The practicality and performance of the presented modular implementation concepts were verified by the close match between the simulated and experimental results.