An integrated ultrasound transducer driver for HIFU applications

This paper presents for the first time an MRI-compatible integrated CMOS amplifier capable of directly driving a piezoelectric ultrasound transducer for High Intensity Focused Ultrasound (HIFU) applications. The amplifier operates in class DE mode loaded with a piezoelectric ultrasound transducer connected in parallel with a shunt capacitor. There is no need for external inductors. The integrated amplifier is implemented with the Teledyne-DALSA 0.8 μm CMOS process. Modeling of the piezoelectric transducer and amplifier design considerations are presented, followed by simulation results obtained using the Spectre simulator. The proposed design achieves over 80% efficiency with 1 W of output power at 1 MHz and an acceptable third harmonic level. The estimated die area of the amplifier is 2 mm².