Stmicroelectronics S.r.l.

Sgs-Thomson Microelectronics S.r.l.

Delta Electronics, Inc.

Consorzio Per La Ricerca Sulla Microelettronica Nel Mezzogiorno

Aldo Vittorio Novelli

Claudio Adragna

Christian Leone Santoro

Angelo Genova

Angelo Alzati

Ignazio Salvatore Bellomo

Antonio Borrello

Roberto Gariboldi

Riccardo Depetro

Stefano Saggini

Claudio Spini

Fabrizio Bognanni

Giulio Ricotti

Milan M Jovanovic

Albino Pidutti

Pietro Menniti

Giuseppe Cantone

Giona Fucili

Laszlo Huber

Alberto Gola

Vincenzo Marano

Luca Giussani

Brian T Irving

Salvatore Pappalardo

Mirko Gravati

Antonella Baiocchi

Roberto Filippo

Alberto De Marco

A circuit includes a timer circuit configured to generate a first control signal defining a first time period and a second control signal defining a second time period. A controller is configured to control a high-side and a low-side transistor of a half-bridge circuit in response to the first and second control signals only during a first switching cycle of the half-bridge circuit. The half-bridge circuit includes a bootstrap capacitor coupled to a node between the high-side and low-side transistors. The controller turns on the low-side transistor for the first time period during the first switching cycle and configured turns off the low-side and the high-side transistors for the second time period during the first switching cycle.

Device for avoiding hard switching in resonant converter and related method

A control device controls a switching circuit for a converter. The switching circuit comprises a half-bridge having a high-side transistor and a low-side transistor. The control device comprises a controller configured to control turning on and turning off said two transistors, so that a square-wave voltage is applied to the transformer primary. The controller is configured to start switching the half-bridge by turning on the low-side transistor. The control device comprises a first timer configure to initially turn on the low-side transistor for a duration given by a first time period useful for pre-charging a bootstrap capacitor couplable to the middle point of the half-bridge, and a second timer configured to keep the low-side transistor and the high-side transistor turned off for a second time period immediately following the first time period and having a longer duration than the first time period.

An effective method enhances energy saving at low load in a resonant converter with a hysteretic control scheme for implementing burst-mode at light load. The method causes a current controlled oscillator of the converter to stop oscillating when a feedback control current of the output voltage of the converter reaches a first threshold value, and introduces a nonlinearity in the functional relation between the frequency of oscillation and said feedback control current or in a derivative of the functional relation, while the control current is between a lower, second threshold value and the first threshold value, such that the frequency of oscillation remains equal or smaller than the frequency of oscillation when the control current is equal to the second threshold value. Several circuital implementations are illustrated, all of simple realization without requiring any costly microcontroller.

Burst-mode control method for low input power consumption in resonant converters and related control device

A control device that controls a switching circuit and minimizes hard switching that occurs in the switching circuit of a half-bridge resonant converter having a high-side transistor and a low-side transistor. The control device is configured to turn the high-side and low-side transistor on and, so that a square-wave voltage is applied to a primary winding of a transformer. The controller starts the switching of the half-bridge converter by first turning on the low-side transistor for a first time period useful for pre-charging a bootstrap capacitor couplable to the middle point of the half-bridge, and then turning the low-side transistor and the high-side transistor off for a second time period that immediately follows and is longer than the first time period.

A control device of a switching circuit of a resonant apparatus is described. The switching circuit comprises at least one half-bridge having a high-side transistor and a low-side transistor connected between an input voltage and a reference voltage; the resonant apparatus comprises a resonant load. The control device is configured to determine the on time period and the off time period of the transistors alternatively and a dead time of both the transistors so that a periodic square-wave voltage is applied to the resonant load. The control device comprises a detector adapted to detect the current sign flowing through the resonant load and a correction circuit configured to extend the current operating time period of said two transistors in response to at least the current sign detected from the detection means.

Control device for a resonant apparatus

A semiconductor structure including a high-voltage transistor; voltage dropping circuitry, at least part of which is overlapping the high-voltage transistor; at least one intermediate contact point to the voltage dropping circuitry, connected to at least one intermediate position between a first and a second end of the voltage dropping circuitry; and at least one external connection connecting the at least one intermediate contact point to outside of the semiconductor structure.

Integrated voltage divider

A control device for a resonant converter, the control device including a first circuit to integrate at least one signal indicating a half wave of a current circulating in a primary winding of a transformer; the first circuit is structured to generate at least a control signal of the switching circuit depending on the integrated signal. The control device includes a second circuit to impose the equality of a switching-on time period of the first and second switches.

Charge-mode control device for a resonant converter

A control device for a resonant converter includes a first circuit structured to rectify a signal indicating the current circulating in the primary winding, a second circuit adapted to integrate at least the rectified signal and structured to generate at least a control signal of the switching circuit according to the integrated signal, and a third circuit adapted to send a reset command to the second circuit so as to inhibit the operation over a time period between the instant when the integrated signal reaches or exceeds a first signal and the instant of the next zero crossing of the signal, indicating the current circulating in the primary winding.

A detecting device detects the midpoint voltage of a half bridge circuit of transistors. The circuit comprises a bootstrap capacitor having one terminal connected to the midpoint node of the half bridge circuit and another terminal connected to a supply circuit. The device comprises a further capacitor connected between a second terminal of the bootstrap capacitor and circuit means adapted to form a low impedance node for a current signal circulating in said further capacitor during the transitions from the low value to the high value and from the high value to the low value of the midpoint voltage. The device comprises a detector to detect said current signal circulating in said further capacitor and to output at least a first signal indicating the transitions from the low value to the high value or from the high value to the low value according to said current signal.

Detecting device for the midpoint voltage of a transistor half bridge circuit

A resonant dc-dc converter converts dc input voltage to a dc output voltage. The converter includes switching, switching driving, conversion, and disabling circuits. The switching circuit receives the input voltage and generates a square wave voltage oscillating between the input voltage and a low value, at a frequency with a duty cycle. The switching driving circuit drives the switching circuit and includes a timing circuit for setting the frequency and the duty cycle. The timing circuit sets the value of the duty cycle to about 50% when the converter operates in steady state. The conversion circuit generates the output voltage from the square wave voltage based on the frequency and the duty cycle. The disabling circuit temporarily halts the timing circuit after a power on in such a way to temporarily vary the duty cycle of the square wave voltage during a period of the square wave voltage.

Method and circuit for avoiding hard switching in resonant converters

Control device for a switching converter structure comprising at least a first and a second interleaved converter, wherein the control device is configured to designate one converter as master and at least the other converter as slave, to set a time delay of the operating cycle of the slave converter and to synchronize the master and the at the least one slave converter.

Control method and device for a system of interleaved converters using a designated master converter

A protection device for a converter includes at least one power switch that operates for a first time period from the time the overload or short-circuit in the converter has been detected. The protection device includes circuitry to control the power switch to minimize the power deliverable by the converter for a second time period from the end of the first operating time period, as well as circuitry to shut down the converter after the second time period.

Protection device for a converter and related method

A protection device protects a driving device of an electric motor with at least three phases and at least three windings and the driving device comprises a power stage suitable for driving directly said at least three windings. The driving device is suitable for actuating a motor brake operating phase and comprises detectors suitable for detecting the currents that run in the windings of the motor. The protection device comprises selectors suitable for selecting the currents having a single direction between said detected currents and a deactuator suitable for deactuating the power stage during said motor brake operating phase when the sum of the currents having a single direction is greater than a reference current.

Protection device for electric motor driving devices and corresponding driving device

A device for effectuating a digital estimate of a periodic electric signal is described. The device comprising a linear DAC having an output signal, a comparator that compares the output signal of the linear DAC with the periodic electric signal, and logic circuitry having in input the output signal of the comparator and a pulse clock signal. The logic circuitry provides a first digital signal in input to the linear DAC and a second digital signal representative of the estimate of the periodic electric signal.

Device to effectuate a digital estimate of a periodic electric signal, related method and control system for an electric motor which comprises said device

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S. Lorenzo Parabiago, Italy

Aldo Vittorio Novelli