A 10-kV Linear Current-Mode Power Amplifier for Capacitive Actuators

High-voltage linear pulse amplifiers with current output are advantageous for driving piezoelectric or electrorheological actuators because the inherent current ripple of switched-mode power converters can be avoided. The new amplifier provides output voltages up to 10 kV with an output current of 200 mA. Low quiescent currents of 0.6 mA minimize static power loss. Nested feedback loops are applied to ensure symmetrical voltage division among cascaded output insulated-gate bipolar transistors (IGBTs) in half-bridge configurations. Optical isolated output stages control the load current. Local current controllers at the power IGBTs enhance linearity and allow for quasi-complementary circuit design without high-voltage small-signal transistors.The symmetrical rise and fall times of 80 μs are achieved, together with the pulse peak power of more than 1 kW.