21.5 A 3-to-5V input 100V pp output 57.7 mW 0.42% THD+ N highly integrated piezoelectric actuator driver


Simon Chaput, David Brooks, and Gu Wei. 2/2/2017. “21.5 A 3-to-5V input 100V pp output 57.7 mW 0.42% THD+ N highly integrated piezoelectric actuator driver.” In 2017 IEEE International Solid-State Circuits Conference (ISSCC), Pp. 360–361. San Francisco, CA, USA: IEEE. Publisher's Version


Piezoelectric actuators are used in a growing range of applications, e.g., haptic feedback systems, cooling fans, and microrobots. However, to fully realize their potential, these actuators require drivers able to efficiently generate high-voltage (>100V pp ) low frequency (<;300Hz) analog waveforms from a low-voltage source (3-to-5V) with small form factor. Certain applications, such as piezoelectric (PZT) cooling fans, further demand low distortion waveforms (THD+N <; 1%) to minimize sound emission from the actuator. Existing solutions for small PZT drivers typically rely on designs comprising a power converter to step up a low voltage followed by a high-voltage amplifier [1,2,3]. Although envelope tracking can help reduce amplifier power [3], none of these designs can recover the energy stored on the actuator to maximize efficiency. And while a differential bidirectional flyback converter [4] can recover energy, it requires four inductors, thereby incurring large size penalty. This paper introduces a single-inductor, highly integrated, bidirectional, high-voltage actuator driver that achieves 12.6× lower power and 2.1× lower THD+N at a similar size to the currently available state-of-the art solution [1]. Measured results from an IC prototype demonstrate 200Hz sinusoidal waveforms up to 100V pp with 0.42% THD+N from a 3.6V source while dissipating 57.7mW to drive a 150nF capacitor. Beyond PZT actuators, the IC can also drive any type of capacitive load, e.g., electrostatic and electroactive polymer actuators.
Last updated on 04/29/2022