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US 7,460,349 B2Granted
Protection of a power transistor
AssigneeSTMicroelectronics S.r.l.
InventorPietro Fichera
Life of this patent
Estimating the term…
Abstract
A method and a circuit for protecting a transistor that controls the supply of an at least partially inductive load, including lowering the demagnetization voltage of the inductive load with respect to a demagnetization voltage set by a break-over component connected between a conduction terminal and the control terminal of the transistor.
Claims25
A circuit for protecting a transistor coupled to a load, having a first conduction terminal and a control terminal, at least one break-over component in anti-series with a one-way conduction element, the protecting circuit comprising:
- a first resistive element in series with the break-over component;
- and
- a controllable current source connected to a terminal of the one-way conduction element opposite to the terminal coupled to said transistor and connected to a node between the second conduction terminal of the transistor and the load.
A circuit, comprising:
- first and second parallel-coupled transistors, each transistor having a first terminal coupled to a supply terminal, a second terminal coupled to a load terminal, and a control terminal to receive a control signal;
- and
- a protection circuit comprising a first diode coupled in series to a second diode between the first terminal of each transistor and the control terminal of each transistor, a first resistive element coupled in series between the first and second diodes, and a current source coupled to a first terminal of the resistive element and to the load terminal, the current source controlled by a current in the second terminal of the respective transistor.
A circuit, comprising:
- a power transistor having a first terminal coupled to a supply terminal and a second terminal coupled to a load terminal, and a control terminal configured to receive a control signal;
- and
- a protection circuit, comprising:
- an auxiliary transistor having a first terminal coupled to the supply terminal and a second terminal coupled to the control terminal of the power transistor;
- a first diode having a cathode coupled to the supply terminal and an anode coupled to the first terminal of the auxiliary transistor;
- a second diode having an anode coupled to a control terminal of the auxiliary transistor and a cathode coupled to the anode of the first diode;
- a first resistor coupled to the anode of the first diode and to the control terminal of the auxiliary transistor to be in parallel to the first diode;
- and
- a current source coupled to the control terminal of the auxiliary transistor and coupled to the load terminal, the current source including a line coupling a second terminal of the current source to an auxiliary terminal of the power transistor, the current source controlled by the current in the second terminal of the power transistor.
6 more elements
A circuit for protecting a transistor having first and second conduction terminals and a control terminal, and a load coupled to the second conduction terminal, the circuit comprising:
- a break-over component
- a one-way conduction element coupled in series with the break-over component between the first conduction terminal and the control terminal of the transistor, the one-way conduction element having a first conduction terminal coupled to the control terminal and a second conduction terminal coupled to the break-over component;
- a resistive element coupled between the break-over component and the one-way conduction element;
- and
- a controllable current source connected to the second conduction terminal of the one-way conduction element and connected to the second conduction terminal of the transistor, the controllable current source controlled by a current in the second conduction terminal of the transistor.
2 more elements
A circuit for supplying a load, the circuit comprising:
- a plurality of transistor legs connected in parallel between a supply voltage terminal and a load terminal of the load, each transistor leg including a respective transistor having a first conduction terminal, a second conduction terminal that is coupled to the load terminal, and a control terminal;
- and
- a plurality of protection circuits corresponding to the transistors of the transistor legs, respectively, each protection circuit including:
- a break-over component
- a one-way conduction element coupled with the break-over component between the first conduction terminal and the control terminal of the transistor, the one-way conduction element having a first conduction terminal coupled to the gate and a second conduction terminal coupled to the break-over component;
- a resistive element connected between the break-over component and the one-way conduction element;
- and
- a controllable current source connected to the second conduction terminal of the one-way conduction element and connected to the second conduction terminal of the transistor, the controllable current source controlled by a current in the second conduction terminal of the transistor.
5 more elements
Dependencies are inferred from the claim text.