Stmicroelectronics S.r.l.

Davide Ugo Ghisu

Sandro Rossi

Antonio Ricciardo

Fabio Quaglia

Antonio Davide Leone

Marco Terenzi

Dario Bianchi

Andrea Gambero

Giulio Ricotti

Federico Guanziroli

Marco Sambi

Dario Ripamonti

A high voltage driving circuit for driving a load receives a low voltage input signal and generates a high voltage output signal. A short circuit protection circuit including a first electronic switch operated by the low voltage input signal and a second electronic switch operated by a low voltage signal obtained by a voltage division of the output high voltage signal. The first electronic switch causing a first pull-up current to be sent to a capacitive element whose voltage controls an input of a threshold comparator. A second electronic switch causes a second pull-down current to be drawn from the capacitive element whose voltage controls the input of the threshold comparator. A short circuit detection signal is generated at an output of said threshold comparator, indicating a short circuit and capable of inhibiting operation of the driving circuit.

High voltage driving electronic circuit arrangement having a short circuit protection, corresponding apparatus and method

A driver circuit for driving, for example, ultrasonic transducers in medical equipment, such as ultrasound scanning equipment. The driver circuit includes first inputs receptive of a pulsed signal, second inputs receptive of an analog signal, an output for applying a pulsed drive signal or an analog drive signal to a load. A pair of output transistors of complementary polarities are positioned with their current paths in series between opposing supply lines with a connection point intermediate between the transistors of the pair of transistors. The connection point between output transistors is coupled to the output of the circuit. The control terminals of the output transistors, which are coupled together, may be coupled to the first inputs with the driver functioning as a pulser, or else coupled to the second inputs with the driver functioning as a linear driver.

Driver circuit, corresponding ultrasound apparatus and method

A circuit for an ultrasonic channel has a first and a second terminal between which extend a resistive and diode signal paths including a pair of diodes with opposing polarities, for example in anti-parallel. Switching circuitry is coupled with the resistive and diode signal paths and is switchable between first and second states. In the first state, the first and the second terminals are coupled with one another via the resistive signal path. In the second state, the first and the second terminals are coupled with one another via the diode signal path. The switching circuitry includes first and second transistor discharge circuits coupled between first and second drive lines and current paths of these transistors, and coupled to control terminals of these transistors. The control terminals are coupled to the first or second drive line and are non-conductive and conductive in first and second operating states, respectively.

Electronic circuit, corresponding ultrasound apparatus and method

An operational amplifier including an input stage coupled to an input terminal, an output stage coupled to an output terminal, and a gain node between the input stage and the output stage. A bias current source is couplable to the input stage to supply a bias current thereto and a current mirror circuit mirrors the bias current toward the gain node and the output stage. A switch circuit includes a switch activatable to bring the gain node to a pre-bias voltage and a switch coupled to the output stage and switchable between a first state and a second state in which the output stage is active and non-active, respectively&#x2014;. A further switch circuit is coupled to the output terminal and switchable between a first state and a second state in which the output stage is coupled to the output terminal and to a reference level, respectively.

Operational amplifier, corresponding circuit, apparatus and method

A transmission channel transmits high-voltage pulses in a transmission phase and receives echoes of the high-voltage pulses in a receiving phase. The transmission channel includes a buffer with anti-memory circuitry to couple drain conduction terminals of buffer transistors of a high-side of a buffer of the transmission channel to a low-side reference voltage of a low-side of the buffer and couple drain conduction terminals of buffer transistors of the low-side of the buffer to a high-side reference voltage of the high-side of the buffer during the clamping phase.

Transmission channel for ultrasound applications

A high-voltage electronic switch includes first and second transistors defining a current flow path between an input and output of the switch. The transistors have a common point of the current flow path and a common control terminal. A control circuit includes a voltage line receiving a limit operating voltage and first and second branches coupled between the voltage line and the common point and common control terminal, respectively. Further transistors are activated, upon turning-off of the first and second transistors, for coupling the branches to the voltage line. The branches include a parallel connected resistor, diode, and string of diodes with opposite polarities. The diode of the first branch plus string of diodes of the second branch and diode of the second branch plus string of diodes of the first branch provide coupling paths between the voltage line and, respectively, the common point and common control terminal.

Electronic switch, and corresponding device and method

Described herein is a transceiver circuit for a capacitive micromachined ultrasonic transducer (CMUT), provided with: a transmitter stage, which generates excitation pulses for a first node of the CMUT transducer during a transmitting phase, a second node of the CMUT transducer being coupled to a biasing voltage; a receiver stage that is selectively coupled to the first node during a receiving phase and has an amplification stage; a switching stage that couples the receiver stage to the first node during the receiving phase and decouples the receiver stage from the first node during the transmitting phase. The amplification stage is provided with a charge amplifier that has an input terminal and is biased as a function of a biasing voltage; and the switching stage is coupled to the same biasing voltage thereby minimizing an injection of charge into the input terminal upon switching from the transmitting phase to the receiving phase.

Reception and transmission circuit for a capacitive micromachined ultrasonic transducer

An ultrasonic probe includes: an ultrasonic transducer; an amplification stage; a bias circuit, which determines a bias voltage on an input terminal of the amplification stage; and a selector having an intermediate node, a high-voltage switch between the intermediate node and the transducer, and a first low-voltage switch between the intermediate node and the input terminal. A control unit controls the high-voltage switch and the first low-voltage switch so as to alternately couple and decouple the amplification stage and the transducer. A precharge circuit determines a precharge voltage on the intermediate node as a function of the bias voltage, before the amplification stage and the transducer are coupled.

Ultrasonic probe with precharge circuit and method of controlling an ultrasonic probe

A level shifter circuit includes: an input stage for receiving an input signal switchable between a first and a second input level and an output stage to produce a drive signal for the load that is switchable between a first and a second output level. A level translator translates the input signal switching between the input levels into the output stage switching between the output levels. A feedback element coupled to the output stage transfers to the input stage a feedback signal representative of the output level of the output stage. The input stage includes control circuitry sensitive to the input signal and the feedback signal for detecting undesired switching of the output stage between the first and second output levels occurring in the absence of input signal switching between the first and second input levels. The control circuitry inverts the output level of the output stage resulting from undesired switching.

Level shifter circuit, corresponding apparatus and method

A diode comprising a semiconductor body delimited by a front surface and including: a first semiconductor region having a first type of conductivity, facing at least in part the front surface; and a second semiconductor region having a second type of conductivity, the second semiconductor region facing at least in part the front surface and surrounding, at a distance, at least part of the first semiconductor region. The diode further includes: a trench, which extends in the semiconductor body starting from the front surface, for surrounding at least part of the second semiconductor region; and a lateral insulation region, which is arranged within the trench, is formed by dielectric material and contacts at least in part the second semiconductor region.

Diode with reduced recovery time for applications subject to the current recirculation phenomenon and/or to fast voltage variations

A transmission channel transmits high-voltage pulses and receives echos of the high-voltage pulses. The transmission channel includes a current generator circuit, which generates current-integrator drive currents. The control circuitry generates one or more control signals to control generation of current-integrator drive currents by the current generator circuit during transducer-driving periods. A current integrator integrates current-integrator drive currents generated by current generator circuit to generate transducer drive signals.

A switching circuit for transmission channel for ultrasound applications is electrically coupled between a connection terminal and a low voltage output terminal. The switching circuit includes a receiving switch, a high voltage clamp circuit electrically coupled between the connection terminal and a central node, and a low voltage clamping switch electrically coupled between said central node and a reference voltage. The receiving switch is a low voltage switch and is electrically coupled between the central node and the low voltage output terminal. The clamping switch and the receiving switch are controlled in a complementary way with respect to each other. A transmission channel for ultrasound applications includes the switching circuit.

Switching circuit for a transmission channel for ultrasound applications, transmission channel and process for driving a switching circuit

A transmission channel transmits high-voltage pulses and receives echos of the high-voltage pulses. The transmission channel includes a buffer with anti-memory circuitry to couple drains of the buffer transistors to voltage reference terminals during a clamping phase.

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Milan, Italy

Davide Ugo Ghisu