Freescale Semiconductor,inc.

Conti Temic Microelectronic Gmbh

Nxp Usa, Inc.

Philippe Rosado

Laurent Guillot

Uli Joos

Josef Schnell

Kamel Abouda

Norbert Stuhler

Helmut Henssler

Pierre Turpin

Denis Sergeevich Shuvalov

Vasily Alekseyevich Syngaevskiy

Alexander Petrovich Soldatov

Laurent Guillott

Francoise Vareilhias

Françoise Vareilhias

An overcurrent protection device comprises a maximum-allowed-current unit and a power switch. The maximum-allowed-current unit determines a maximum allowed current in real-time. The maximum allowed current is determined at least partially on an instantaneous level of a load voltage. The load voltage is a voltage across a load to be powered. The power switch is connectable with a switch input to a voltage supply and with a switch output to the load, for providing power to said load. The power switch has a conductive state and a nonconductive state, and is arranged to assume the nonconductive state in response to an indication that a current through the power switch is exceeding the maximum allowed current. A method of operating a power switch is also described.

Overcurrent protection device and method of operating a power switch

A method is intended to make it possible to drive a PTC electrical load element with a switching unit with the highest possible operational reliability. For this purpose, the electric current is switched off if a predetermined current threshold value is exceeded, the magnitude of the current threshold value being determined from the operating parameters of the load element.

Method for driving a PTC electrical load element

Power supply apparatus with overload protection comprising a switch responsive to an input signal for switching between an ON-state for supplying current from a source of power to a load and an OFF-state for interrupting the supply of current to the load, and protection means responsive to an overload condition to switch the switch to the OFF-state. The protection means is responsive to a first overload condition during an initial phase after the switch switches to the ON-state so as to switch the switch back to the OFF-state and maintain the switch in the OFF-state. The protection means is subsequently responsive to a second overload condition if the first overload condition is not detected during the initial phase so as to switch the switch to the OFF-state and subsequently switch the switch back to the ON-state after an interval of time. The protection means is responsive to the current exceeding a first threshold value in detecting the first overload condition, and is responsive to the current exceeding a second threshold value in detecting the second overload condition, the second threshold value being lower than the first threshold value. The protection means is responsive to a temperature of the switch means exceeding a temperature threshold value in detecting at least the first overload condition.

Power switching apparatus with overload protection

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Fonsorbes, France

Philippe Rosado