A linear 10 kV power amplifier for piezo actuators

Linear pulse amplifiers with current mode output are advantageous for driving high voltage capacitive loads like piezoelectric or electrorheological actuators. The new amplifier implements output voltages up to 10 kV with 2 kW peak power and 80 μs rise time. Low quiescent current of 0.6 mA minimizes static power losses. The structure consists of multiple stacked feedback loops in order to reach high transfer linearity and a symmetrical voltage division among the cascaded output power transistors. The linear approach eliminates the inherent ripple of switched mode power amplifiers and improves rise and fall times by at least one order of magnitude.