Stmicroelectronics S.r.l.

Stmicroelectronics Application Gmbh

Stmicroelectronics Design and Application S.r.o.

Donato Tagliavia

Calogero Andrea Trecarichi

Giovanni Luca Torrisi

Sergio Tommaso Spampinato

Antonino Torres

Ludek Beran

Vincenzo Polisi

Francesco Nino Mammoliti

Jochen Barthel

A control circuit for a voltage source generates a reference signal for a voltage source, wherein the reference signal indicates a requested output voltage to be generated by the voltage source. A digital feed-forward control circuit computes a digital feed-forward regulation value indicative of a requested output voltage by determining a maximum voltage drop at strings of solid-state light sources. A digital feed-back control circuit determines a minimum voltage drop for current regulators/limiters for the strings and determines a digital feed-back correction value as a function of the minimum voltage drop. The control circuit then sets the reference signal after a start-up as a function of the digital feed-forward regulation value and corrects the reference signal as a function of the digital feed-back correction value.

Current supply system, related integrated circuit, power supply system and method of operating a current supply system

A method includes generating a control signal for controlling a switch element, and determining at each switching cycle alternation of an ON interval with storage of energy in the inductor element starting from an input voltage, and an OFF interval with transfer of the energy stored in an inductor element into a storage element on which an output voltage is present. The method includes when the inductor current reaches the first threshold value before the end of a first interval, determining the end of the ON interval at the end of the first interval. The method includes following detection of the ON interval having a duration equal to the first interval, the detection being indicative of a possible short-circuit condition at output, determining the OFF interval having a second duration equal to a lengthened interval longer than the first duration.

Device and method for controlling a voltage regulator and corresponding voltage regulator

An electronic system to discharge a transformer in case of a failure during a charging phase of the transformer. The system includes the transformer having a primary winding with a first terminal connected to a battery voltage and with a second terminal for generating a primary voltage signal, includes a switch serially connected to the primary winding and having a control terminal carrying a control voltage signal for opening or closing the switch and includes an electronic circuit. The electronic circuit further includes a current generator and a voltage clamping.

Electronic ignition system for an engine of a vehicle in case of failure

A switching system for a combustion engine ignition system comprises a switching device switchable between an accumulation condition and a transfer condition to activate an ignition element. The switching system comprises control logic that provides a control signal for controlling the switching device, measures a progress indicator indicative of progress in switching the switching device from the transfer condition to the accumulation condition, and causes the control signal to vary with a first variation rate during a first stage until the progress indicator reaches a first progress condition. The control logic causes the control signal to vary with a second variation rate, lower than the first variation rate, during a second stage until the progress indicator reaches a second progress condition, and causes the control signal to vary with a third variation rate, higher than the second variation rate, during a third stage of the preliminary switching.

Soft turn-on in an ignition system of a combustion engine

A flyback DC--DC converter employs a flyback transformer for storing and transferring energy to a load having an auxiliary winding whose voltage is compared by a comparator with a threshold to detect its crossing. As a consequence, a power transistor driving the primary winding of the transformer is switched on through a control flip-flop, for a new phase of conduction and accumulation of energy, whose duration is established by a secondary control loop of the output voltage producing the switching off of the power transistor for a successive energy transfer phase toward the load of the energy stored in the transformer during the preceding conduction phase. The converter has a wholly integrated control circuit that includes a second comparator of the voltage existing on the current terminal of the power transistor connected to the primary winding of the transformer with respect to the ground potential of the circuit. Furthermore, a delay network is coupled in cascade to the output of a first comparator and has an output coupled to a second input of a logic gate, so that under steady state functioning conditions of the converter, the setting of the flip-flop is done by the second comparator rather than by the first comparator.

Wholly integrated switch-on control loop of a high voltage power

A method and device of protection from the effects of a persistent short circuit of the output of a DC-DC flyback converter self-oscillating either at a variable frequency or functioning at a fixed frequency in a discontinuous manner is provided. The voltage induced from the current flowing in a secondary winding of a transformer on the auxiliary winding is rectified and filtered to power, during a steady state of operation, the control circuitry of the converter. The turning on of the power switch is driven during a start-up or recovery phase by a primary control loop, when the supply voltage of the control circuit reaches or is over a preestablished enabling threshold of the control circuit. A secondary control loop includes a photocoupler of the output error voltage to an input of the control circuitry to which a compensation capacitor is connected. An output short circuit condition is discriminated from a start-up or recovery condition by comparing the voltage present on the auxiliary winding with a preestablished threshold which is higher than the voltage that is induced on the auxiliary winding under a short circuit condition of the secondary winding. And, the voltage existing on the compensation capacitor is compared with a second threshold of value equal or close to the value of maximum charge of the compensation capacitor, within a time interval sufficiently delayed from the turn-off instant of the power switch.

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Acireale, Italy

Donato Tagliavia