High-Voltage Piezoelectric Drivers for Inkjet Print Heads
Flexible Solutions for Print Head Designs
Proven Solutions to Meet Design Requirements
- High current capability
- High slew rate
- Low on-resistance
- Low drift
- Low-temperature coefficient
- Tradeoff between voltage, current, slew rate, power consumption, and channel density
Piezoelectric Driver Circuit Topologies
- Open-drain output
- Up to 300V
- Unipolar push-pull output
- Up to 300V
- Bipolar push-pull output
- Up to 200V
- Operational amplifier
- Up to 300V up to 1000 V/ms
Applications
- Paper printing
- Textile printing
- Ceramic tile printing
- OLED panel printing
- 3D printing
- Biomedical printing
Piezoelectric Print Head Actuation
Inkjet Printer Types Explained
Continuous Ink
Ink droplets are generated continuously and accelerated toward a printing target. On their way, these ink droplets pass by high-voltage electrodes controlled by fast switching HV drivers. During this process some droplets are electrostatically charged, while others are not. Next, they pass by a high-voltage deflection plate. The uncharged droplets are allowed to reach the target, while the charged ones are deflected into an ink gutter for recycling.
Drop-on-Demand (DoD)
High-voltage pulses applied to a piezo ink chamber alter the state of the chamber in order to interchangeably suck in, form and push out a droplet of ink and then propel it in direction of target (paper, fabric, etc.). To match the resonance characteristics of the ink chamber, the HV driver generates a series of high-voltage pulses of a particular height, duration and shape.
How Does Piezoelectric Material Work?
Piezoelectric Load Characteristics
The piezoelectric element behaves like a capacitive load
- The capacitance varies from a few tens of picofarad to a few nano-farads
- Series resistance varies from a few tens of ohms to a few hundreds of ohms
- Slew rate: dVc/dt = I/C