The informative signal of the vast majority of sensors on piezoelectric transducers is the ToF (Time-of-Flight) of ultrasonic oscillations, and its formation is realized by measuring the delay between the pulses of oscillations emitted by the actuator and the pulses of these oscillations received by the sensor. However, the processes of forming this informative signal and the electronic means of implementing these processes are characterized by a significant influence of extraneous factors, the compensation of which is largely problematic. Following this problem, this work solves the problem of embedded self-diagnosis of piezoelectric sensors signal converters. Methods of intellectualization of measurement processes are used based on the redundancy theory and its further development in the field of redundancy information theory, measuring technology, and sensors. It is proposed to supplement the input signal path of the sensor device with a specialized circuit for activating self-oscillations of the piezoelectric transducer. The proposed method is based on the monitoring of transient processes and oscillations at the frequency of natural oscillations of piezoelectric transducers during periodic switching of the latter to the input of the transimpedance amplifier TIA. In accordance with the proposed solution, the transimpedance amplifier is used to form damping self-oscillations, the frequency, amplitude and decay rate of which are monitored by the drift of the parameters of the piezoelectric transducer. The task of optimizing the operation modes of the circuit unit based on the transimpedance amplifier based on the criterion of maximum efficiency in the formation of an informative signal of the stability of the operation of piezoelectric transducers has been solved. The signal path of the built-in system of ultrasonic piezoelectric sensors with the self-diagnosis function UCQD (U-sound Front-end with in-situ CQ Diagnostic) is implemented using a programmable system on a PSoC (Programmable System on Chip) PSoC 5LP series (Cypres, Infineon Technologies).
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