A four-channel, ±36 V, 780 kHz piezo driver chip for structural health monitoring

This paper describes a four-channel piezo driver chip for use in active structural health monitoring. Each channel can drive a piezoelectric transducer with a continuous wave signal of ±36 V and 780 kHz. The waveform is synthesized using filtered pulse width modulation (PWM), where the pulse transition times are pre-computed through a least square optimization problem. A calibration technique is introduced to achieve sub-nanosecond timing accuracy and -40.5 dB signal distortion. A 13 mm² proof-of-concept IC was fabricated in a 0.25 μm BCD process and evaluated within an application test bed.