Stmicroelectronics S.r.l.

Alessandro Parisi

Giuseppe Palmisano

Egidio Ragonese

Nunzio Spina

Nunzio Greco

Giuseppe Papotto

Andrea Cavarra

Alessandro Finocchiaro

Pierpaolo Lombardo

A flash analog-to-digital converter (ADC) receives an input control signal and performs coarse tuning of a frequency of an output signal, produced between first and second nodes having an inductance coupled therebetween. The flash ADC quantizes an operating frequency range for the output signal produced between the first and second nodes as M·Δf, where M is an integer from 0 to N−1, where N is a number of intervals into which a frequency range for the output signal is divided, and where Δf is a resulting frequency step produced by the quantizing. The value of M is generated based upon the input control signal and a word controlling switches of a plurality of switched capacitance circuits associated with the first and second nodes to close ones of those switches associated with the control word to coarsely tune the frequency of the output signal.

Oscillator circuit, corresponding radar sensor, vehicle and method of operation

A PLL has a tunable resonator including an inductance and variable capacitance coupled between first and second nodes, and capacitances coupleable between the nodes. A control node is coupled to the variable capacitance and receives a control signal for tuning the resonator. A biasing circuit biases the resonator to generate an output. A PFD circuit senses timing offset of the output with respect to a reference and asserts first or second digital signals dependent on the sign of the timing offset. A charge pump generates the control signal based on the first and second digital signals. A timer asserts a timing signal in response to a pulse sensed in a reset signal and de-asserts the timing signal after a time interval. A calibrator couples selected capacitances between the first and second nodes as a function of the second digital signal, in response to assertion of the timing signal.

Phase-locked loop circuit, corresponding radar sensor, vehicle and method of operation

Disclosed herein is a tunable resonant circuit including an inductance directly electrically connected in series between first and second nodes, a variable capacitance directly electrically connected between the first and second nodes, and a set of switched capacitances coupled between the first and second nodes. The set of switched capacitances includes a plurality of capacitance units, each capacitance unit comprising a first capacitance for that capacitance unit directly electrically connected between the first node and a switch and a second capacitance for the capacitance unit directly electrically connected between the switch and the second node. Control circuitry is configured to receive an input control signal and connected to control the switches of the set of switched capacitances. A biasing circuit is directly electrically connected to the tunable resonance circuit at the first and second nodes.

A voltage controlled oscillator (VCO) includes: a pair of inductors coupled in series; a first pair of varactors coupled in series, and a second pair of varactors coupled in series. A first common mode node is between the respective varactors of the first pair of varactors and a second common mode node is between the respective varactors of the second pair of varactors. A supply voltage node is switchably coupled to the first common mode node through a first switch, the supply voltage node being a node located between the pair of inductors. A control voltage node (V) is switchably coupled to the second common mode node through a second switch.

Voltage-controlled oscillator and method for using the same

A DC-DC converter includes: an transformer having a primary winding and a secondary winding magnetically coupled to the primary winding; a power oscillator applying an oscillating signal to the primary to transmit a power signal to the secondary winding; a rectifier connected to the secondary winding of the transformer to obtain an output DC voltage by rectification of the power signal; comparison circuitry to generate an error signal representing a difference between the output DC voltage and a reference voltage; a transmitter connected to the secondary winding of the transformer to apply an amplitude modulation to the power signal at the secondary winding of the transformer in response to the error signal to thereby produce an amplitude modulated signal at the primary winding; and a receiver and control circuit connected to the primary winding to control an amplitude of the oscillating signal as a function of the amplitude modulated signal.

Galvanically isolated DC-DC circuit converter with data communication, corresponding system and corresponding method

An oscillator includes a tunable resonant circuit having an inductance and a variable capacitance coupled between first and second nodes, and a set of capacitances selectively coupleable between the first and second nodes. An input control node receiving an input control signal is coupled to the variable capacitance and set of capacitances. The tunable resonant circuit is tunable based on the input control signal. A biasing circuit biases the tunable resonant circuit to generate a variable-frequency output signal between the first and second nodes. A voltage divider generates a set of different voltage thresholds, and a set of comparator circuits with hysteresis compares the input control signal to the set of different voltage thresholds to generate a set of control signals. The capacitances in the set of capacitances are selectively coupleable between the first and second nodes as a function of control signals in the set of control signals.

A DC-DC converter includes a transformer having primary and secondary windings, a power oscillator applying an oscillating signal to the primary winding to transmit a power signal to the secondary winding, a rectifier obtaining an output DC voltage by rectifying the power signal at the secondary winding, and comparison circuitry generating an error signal representing a difference between the output DC voltage and a reference voltage value. A transmitter connected to the secondary winding performs an amplitude modulation of the power signal at the secondary winding to transmit an amplitude modulated power signal to the primary winding, the amplitude modulation based upon the error signal and modulating a stream of data to the primary winding. A receiver coupled to the primary winding demodulates the amplitude modulated power signal to recover the error signal and the stream of data. An amplitude of the oscillating signal is controlled by the error signal.

An oscillator is coupled to a first side of a galvanic barrier for supplying thereto an electric supply signal. The oscillator is configured to be alternatively turned on and off as a function of a PWM drive signal applied thereto. A receiver circuit coupled to the galvanic barrier receives therefrom a PWM power control signal. A signal reconstruction circuit coupled between the receiver circuit block and the oscillator provides to the oscillator a PWM drive signal reconstructed from the PWM power control signal. The signal reconstruction circuit includes a PLL circuit coupled to the receiver circuit block and configured to lock to the PWM control signal from the receiver circuit block. A PLL loop within the PLL circuit is sensitive to the PWM drive signal applied to the oscillator. The PLL loop is configured to be opened as a result of the power supply oscillator being turned off.

Galvanic isolation circuit and system and a corresponding method of operation

A DC-DC converter includes a power oscillator connected to a first transformer winding, and a channel conveying a data stream through galvanic isolation by power signal modulation. A rectifier rectifies the power signal to produce a DC voltage. A comparator produces an error signal from the DC voltage and a reference voltage. An analog-to-digital converter converts the error signal to a digital power control value. A multiplexer multiplexes the digital power control value with the data stream to obtain a multiplexed bitstream. A transmitter driven by the multiplexed bitstream performs amplitude modulation of the power signal at a second transformer winding. A receiver connected to the first winding demodulates the amplitude modulated power signal. A demultiplexer demultiplexes the data stream and the digital power control value. A digital-to-analog converter converts the digital power control value to an analog control signal for the power oscillator.

A galvanic isolation circuit is formed by a differential transformer having primary and secondary windings for transmission of signals over a carrier between the primary and the secondary windings of the transformer. A galvanic isolation oxide layer is provide between the primary and secondary windings. Each winding includes include a center tap providing a low-impedance paths for dc and low frequency components of common-mode currents through the differential transformer. A pass-band stage is coupled to the secondary winding of the transformer and configured to permit propagation of signals over said carrier through the pass-band amplifier stage while providing for a rejection of common-mode noise.

Galvanic isolation circuit, corresponding system and method

A galvanic isolation is provided between a first circuit and a second circuit. A first galvanically isolated link is configured to transfer power from a first circuit to a second circuit across the galvanic isolation. A second galvanically isolated link is configured to feed back an error signal from the second circuit to the first circuit across the galvanic isolation for use in regulating the power transfer and further configured to support bidirectional data communication between the first and second circuits across the galvanic isolation.

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Mascalucia, Italy

Alessandro Parisi