Sgs-Thomson Microelectronics S.a.

Stmicroelectronics S.a.

Jean-Michel Ravon

Luc Wuidart

Michel Bardouillet

Antoine Pavlin

Alain Bailly

Maxime Teissier

Jean-Marie Bourgeois

Joseph Notaro

The present invention relates to a system for providing a regulated voltage meant to supply a load, including a source for providing a substantially constant current approximately corresponding to the maximum current likely to be surged by the load, and a device receiving the constant current and regulating the load supply voltage, at least one capacitor being connected between an output terminal of the regulation device and the ground.

System for providing a regulated voltage to supply a load

A circuit for providing a D.C. voltage of high value from the output of a rectifying bridge on a capacitor of high capacitance, and for providing low supply voltages, including a first diode connected between the output of the rectifying bridge and the capacitor, first and second cascode-mounted transistors, circuitry for setting the potential of the control terminal of the first transistor, circuitry for reducing the potential of this control terminal when the rectified voltage exceeds a predetermined value, a regulation circuit connected at the connection node of the first and second transistors, and circuitry for applying, to the second transistor, a turn-on pulse of determined duration after the output voltage of the bridge has exceeded the determined value.

High and low voltage D. C. power supply

System for providing a regulated voltage during abrupt variations in

A non-isolated voltage converter, of switch-mode type, includes a capacitor between terminals that provide an output voltage regulated by a circuit that controls a switch that provides current to an inductive element. A local supply for the control circuit receives energy from the inductive element. In one embodiment, the inductive element has a tab between two windings, and the output voltage of the converter is smaller than the local supply voltage of the control circuit. In another embodiment, a diode is interposed between a positive terminal of the output capacitor and a positive terminal of a capacitor of the local supply of the control circuit. The negative terminal of the local supply capacitor is connected to the mid-point of a series association of the switch with the inductive element. A zener diode is interposed, in series with the local supply capacitor and the local supply diode, between the mid-point and the positive output terminal.

Non-isolated low voltage switch-mode power supply

The present invention relates to a device for limiting transient variations of a voltage for supplying a load from a dc/dc converter, including an input terminal, that receives the voltage provided by the converter, and connected to an output terminal of the device connected to the load; a first power transistor connected between a supply voltage of the converter and the output terminal; a second power transistor connected between the output terminal and the ground; and means for linearly and individually controlling each power transistor in case of an abrupt variation of the load.

Device for limiting transient variations of a supply voltage

A circuit for controlling two power transistors (24, 26) used an synchronous rectifiers in the secondary side of a switched mode power supply is provided. Current detector circuits (40, 42) measure current through parasitic diodes (28, 30) of the power transistors. It is shown that the synchronisation achieved is more accurate, and the resultant device is simpler and cheaper than previous solutions.

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Fuveau, France

Jean-Michel Ravon