Efficient high voltage pulser for piezoelectric air coupled transducer

Area of Science:

• Electrical Engineering
• Ultrasound Technology
• Materials Science

Background:

• Air-coupled ultrasound imaging utilizes piezoelectric transducers for non-contact sensing.
• High voltage pulsers are essential components for driving these transducers effectively.
• Optimizing pulser design impacts imaging resolution and energy efficiency.

Purpose of the Study:

• To design and characterize a high voltage pulser for air-coupled ultrasound imaging systems.
• To investigate the performance of the pulser with piezoelectric transducers.
• To analyze the pulser's energy consumption and operational frequency limits.

Main Methods:

• Utilized two N-channel MOSFETs and a 1200V high/low side driver IC.
• Implemented a delay and skew circuit to minimize cross-conduction.
• Employed PSPICE simulations to analyze component and operational parameter influences.
• Conducted experimental verification against simulations and theoretical models.

Main Results:

• The pulser consumes 650μJ at 1kV and 4μJ at 50V for a 500pF capacitive load.
• Achieved pulse trains up to 1MHz with 50V-1kV amplitude and 10A peak current.
• Demonstrated 40ns rise time and 32ns fall time at 1kV into a 200kHz transducer, meeting 1MHz bandwidth requirements.

Conclusions:

• The designed high voltage pulser is suitable for air-coupled ultrasound applications.
• The pulser's performance characteristics align with the demands of high-frequency piezoelectric transducers.
• The study validates the pulser's efficiency and operational capabilities for advanced imaging.