Energy and pulse control possibilities using ultra-tight integration of electronics and piezoelectric ceramics

This paper reports on investigations of the electrical energy needed to generate ultrasound pulses with piezoelectric crystals and compares measurements with system simulations using SPICE models. The piezoelectric device used is a 16 mm diameter Pz27 crystal with a nominal resonance frequency f_oos,nom of 4.4 MHz. An optimized ASIC driver stage with 5 V supply voltage is mounted directly on the piezoelectric crystal to generate square-wave excitation pulses. The absence of wiring between driver and crystal provides excellent pulse control possibilities. It is shown that the power consumption varies with the excitation pulse width, which also affects the received ultrasound energy in a pulse echo system. To achieve maximum output ultrasound energy, an excitation pulse width of 100 ns= 0.44/f_osc,nom should be used. At a repetition rate of 1 kHz, the power consumption including losses in the driver stage varies from 96 μW for an excitation pulse width of 240 ns, up to 126 μW for an excitation pulse width of 130 ns. The performed SPICE simulations agree well with measured data.