Device for controlling an ultrasonic transducer and ultrasonic measuring device having such a control device for the ultrasonic transducer

A device for controlling an ultrasonic transducer and for evaluating measuring signals delivered by the ultrasonic transducer, comprising:

• an integrated circuit having two IC terminals led to an outside of the integrated circuit for electrical connection to the ultrasonic transducer,
• wherein an alternately reversible control voltage can be applied to the two IC terminals of the integrated circuit for emitting an ultrasonic burst signal in a control phase, and an evaluation voltage which can be output by the ultrasonic transducer is applied to the two IC terminals of the integrated circuit when an ultrasonic echo signal is received in a reception phase,
• wherein the evaluation voltage is in a low-voltage range of more than 0 V and up to 10 V, and the control voltage is in a high-voltage range, which comprises voltages that are greater than those of the low-voltage range by up to two powers of ten,
• a control unit formed as a component of the integrated circuit for generating the control voltage, wherein the control unit is provided with a full bridge circuit arranged between a supply potential and a reference potential, in particular ground, with two half bridge circuits each having two semiconductor driving switches, whose two circuit nodes each connecting two semiconductor driving switches are electrically connected to the two IC terminals of the integrated circuit,
• an evaluation unit formed as a component of the integrated circuit with an amplifier processing evaluation voltages in the low-voltage range with two input terminals which are electrically connected to the two IC terminals of the integrated circuit,
• a voltage limiting element in each electrical connection between the input terminals of the amplifier and the two IC terminals of the integrated circuit, wherein both voltage limiting elements limit the voltage applied to the input terminals of the amplifier to a value in the low-voltage range, wherein the voltage limiting elements are each designed as FET transistors switched as source followers that continuously limit the voltage at the input terminals of the amplifier by clamping the voltage to a value in the low-voltage range,
• a control unit formed as a component of the integrated circuit for controlling the semiconductor driving switches,
• wherein, for applying the control voltage to the IC terminals of the integrated circuit, alternately two semiconductor driving switches of the four semiconductor driving switches, can be switched on and two semiconductor driving switches of the four semiconductor driving switches can be switched off, and
• wherein for evaluating the evaluation voltage applied to the IC terminals of the integrated circuit, the four semiconductor driving switches are switched off.