Driver Circuits for
Piezo Actuators
High performance amplifiers, unlocking the full potential of your piezo-electric actuators
Powering Precision with Advanced Electronics
Understanding the critical role of amplifier electronics in piezo actuator systems
Piezo materials mechanically deform in response to an applied electric field (and vice versa), known as the piezo-electric effect.
Piezo actuators react to electric charge. A (power) amplification device, also known as piezo driver, is required to convert a control setpoint to the appropriate level of charge or voltage.
The performance of piezo drivers is described by several specifications that largely depend on the application of interest, often requiring custom amplifier design.
Semiconductor manufacturing, precision optics, aerospace, automotive, medical devices, and advanced manufacturing systems.
What Are Piezo Actuators?
Piezoelectric actuators are smart materials that exhibit the piezoelectric effect - the ability to generate mechanical motion when an electric field is applied. This unique property makes them ideal for precision positioning applications in a wide range of fields across many sectors.
- • Nanometer precision: Sub-nanometer resolution for ultra-precise positioning
- • High force density: Generate significant force in compact form factors
- • Fast response: Microsecond response times for dynamic applications
- • High energy efficiency: Improving thermal management and enabling compact energy provision systems (batteries)
- • Compact form factor: Enabling dense or miniaturized solutions in precision equipment
Why Do You Need Piezo Drivers?
There are many reasons why a driving piezo amplifier circuit between the output of your control system and the input of your piezo-electric actuator is required. Generally, piezo actuators react to charge, exhibiting a close relationship between force and charge. Therefore, the ideal piezo driver is a charge amplifier. Depending on the application, it can be acceptable to assume a constant piezo capacitance. Therefore, many piezo drivers are voltage amplifiers.
Voltage and Current Drive Requirements
Piezo actuators require high driving voltages (typically 100V-1000V+) to achieve full displacement range. Depending on the capacitive piezo size and the required slew rate, a high drive current might be required as well. A dedicated amplifier is needed to ensure adequate drive capabilities.
Dynamic System Response
Piezo actuators behave as (large) capacitors (nF to μF range). Specialized drivers are needed to charge and discharge these capacitive loads while maintaining stability and exhibiting appropriate dynamic behavior. The amplifier connected to the piezo load shall ensure a sufficiently high drive bandwidth for your application.
Precision Control
Many applications in the field of (opto-)mechatronics require precise motion control. The piezo driver electronics shall therefore exhibit low noise output behavior over a large frequency range.
Technical Challenges
Dynamically driving capacitive piezo loads might seem daunting at first. At PoweringPiezos, we are specialized at decoupling the different performance aspects and building a robust design that fits the application. Some of the most relevant technical challenges are highlighted below.
Next to stability, a fast step response and sufficient bandwidth of the amplitude/phase frequency response are crucial to many piezo use cases. Predictable small-signal dynamic behavior is key when using the piezo driver in feedback positioning systems.
High-frequency, full-stroke actuation of a large piezo actuator may require high drive currents. For applications that need high full-power bandwidth, it is suitable to not only build a high-voltage piezo amplifier but to also foresee high current drive capability.
Piezo actuators are capacitive loads. Due to their reactive nature, they can be very power efficient. Class D (switching) amplifiers can exploit this property. A careful trade-off between power efficiency, noise and distortion needs to be made when considering the amplifier class (A/AB/D,etc.)
When precision matters, you do not want the piezo driver electronics to be the bottleneck to performance. Circuit topology and component selection are needed to ensure that the noise performance of the piezo-electric amplifier remains within the specifications.
Key Industries & Applications
- • Semiconductor Manufacturing: Wafer positioning systems, lithography alignment, probe station positioning, die bonding equipment
- • Precision Optics: Laser beam steering, mirror positioning, adaptive optics, interferometry systems
- • Aerospace & Defense: Satellite pointing systems, optical payload stabilization, vibration isolation, precision instrumentation
- • Medical Devices: Surgical positioning systems, ultrasound transducers, drug delivery systems, microscopy stages
- • Automotive: Fuel injection systems, active suspension, engine mount control, mirror positioning
- • Advanced Manufacturing: CNC machine tool positioning, 3D printing systems, quality inspection equipment, assembly automation
Ready to Get Started?
Whether you need a standard product, custom design, or just have questions about piezo amplifier technology, we're here to help.
