MOS power transistor device with temperature compensation
AssigneeSGS-Thomson Microelectronics S.A.
InventorsGuido Brasca, Edoardo Botti
Life of this patent
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Abstract
A device including a MOS power transistor, and a temperature sensor including a bipolar transistor integrated in the MOS transistor and having its emitter and collector connected directly to the source and gate terminals respectively of the MOS transistor. Parallel to the base-emitter junction of the bipolar transistor, there is connected a voltage source for biasing the junction to such a value that the bipolar transistor remains off at room temperature, and absorbs the maximum current supplied by a drive circuit of the MOS transistor at the maximum permissible temperature TUM. At temperature TUM, the bipolar transistor takes over control of the gate-source voltage of the MOS transistor for maintaining thermal feedback of the device at maximum temperature TUM.
Claims25
An MOS power transistor device, comprising:
- an MOS power transistor having source, gate, and drain regions connected to respective source, gate, and drain terminals, the source and drain regions being formed in a chip portion of semiconducting material;
- and
- a temperature sensor including a bipolar transistor integrated in the chip portion, surrounded at least partially by the MOS power transistor, and having an emitter region connected directly to the source region, and a base region connected to a separate fourth terminal of the device.
An MOS power transistor integrated circuit, comprising:
- an MOS power transistor;
- and
- a temperature sensor including a bipolar transistor having a first terminal coupled to a first terminal of the MOS power transistor and a second terminal coupled to a first external terminal on the integrated circuit.
A method of regulating a gate-source voltage drop in an MOS transistor to control a temperature of the MOS transistor, comprising the steps of:
- coupling a gate region of the MOS transistor to a collector region of a bipolar transistor and a source region of the MOS transistor to an emitter region of the bipolar transistor;
- and
- biasing the bipolar transistor so that the bipolar transistor is off at a first predetermined temperature, conducts a maximum current at a second predetermined temperature, and conducts a current in a range between the first and second predetermined temperature as a function of a temperature of the bipolar transistor.
Dependencies are inferred from the claim text.