Stmicroelectronics S.r.l.

Simone Buonomo

Rosario Scollo

Giovanni Vitale

A drive circuit for an emitter switching configuration of transistors having a cascode connection of a power bipolar transistor and of a power MOS transistor control the saturation level of the configuration in applications which provide highly variable collector currents. The drive circuit includes a circuit operable to apply a varying voltage value to the control terminal of the bipolar transistor. A current/voltage converter senses a collector current flowing in the power bipolar transistor and controls conduction of a first transistor responsive thereto, the conduction of the first transistor controlling the conduction of a second transistor so as to vary the control terminal voltage in proportion to the sensed collector current of the power bipolar transistor.

Driven circuit of an emitter switching configuration to control the saturation level of a power transistor when used with highly variable collector currents

A driving network for an emitter-switching circuit comprises a pair of cascode-configured transistors, the one of the bipolar type and the other of the MOS type, and the driving network is of the type comprising a driving block for respective conduction terminals and of said pair of transistors. The driving network () further comprises sensor means in the driving block suitable for measuring a voltage to be compared with a reference value in a first comparator block. A negative feedback network between the output of the comparator and the driving block to provides a voltage value to said driving block to bias the conduction terminal of the bipolar transistor of the emitter-switching circuit in order to regulate the storage time thereof.

Emitter switching driving network to control the storage time

A driving circuit is provided for a control terminal of a bipolar transistor in an emitter-switching configuration. The emitter-switching configuration is between first and second voltage references. The driving circuit includes at least one first resistive element connected to the control terminal of the bipolar transistor and a first capacitor connected to the resistive element with respect to a first circuit node and to the second voltage reference. The driving circuit further includes a Zener diode connected between the first circuit node and a second circuit node, and a second capacitor between the second circuit node and the second voltage reference.

Driving circuit for a control terminal of a bipolar transistor in an emitter-switching configuration and corresponding method for reducing the VCESAT dynamic phenomenon

A driving circuit is provided for a control terminal of a bipolar transistor in an emitter-switching configuration. The emitter-switching configuration is between a resonant load and a voltage reference. The driving circuit includes at least one capacitor between the control terminal of the bipolar transistor and the voltage reference. The driving circuit further includes an additional resonance capacitor between a collector terminal of the bipolar transistor and a circuit node, a first diode between the circuit node and the control terminal, and a second diode between the circuit node and the voltage reference.

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Augusta, Italy

Simone Buonomo