DEVICE FOR CONTROLLING AT LEAST ONE TRANSISTOR

• US 20150180462A1
• Filed: 07/11/2013
• Published: 06/25/2015
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Valeo Siemens eAutomotive France SAS (Valeo SE)
• Original Assignee: Valeo Systemes De Controle Moteur (Valeo SE)
• Inventors: Bouchez, Boris, Grenier, Mathieu
• Granted Patent: US 9,484,907 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03K 17/0822 in field-effect transistor switches
• CPC Class Codes: H03K 17/0828 in composite switches
• CPC Class Codes: H03K 17/166 Soft switching
• CPC Class Codes: H03K 17/168 in composite switches
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors

Abstract

A device for controlling at least one transistor is disclosed. The device includes the transistor, which includes a control electrode and two other electrodes, a main control circuit connected to the control electrode of the transistor and configured to control the state of the transistor in a main operating mode, and an auxiliary control circuit configured to inject, in an auxiliary operating mode. An auxiliary current opposed to the current flows between the main control circuit and, the control electrode of the transistor.

Claims

1. A device for controlling at least one transistor, comprising:

said at least one transistor comprising a control electrode and two other electrodes;

a main control circuit connected to the control electrode of the transistor and configured so as to control the state of the transistor in a main operating mode;

an auxiliary control circuit configured to inject, in an auxiliary operating mode, an auxiliary current opposed to the current flowing between the main control circuit and the control electrode of the transistor; and

a power amplifier circuit, notably of the “

push-pull”

type, positioned between the main control circuit and the control electrode of the transistor, the auxiliary control circuit being arranged in such a way that the injected current flows through the power amplifier circuit when the auxiliary operating mode is used.

2. The device as claimed in claim 1, the auxiliary operating mode being used when a predetermined condition is present.

3. The device as claimed in claim 2, the predetermined condition relating to the value of the time derivative of the current flowing between the electrodes of the transistor other than the control electrode.

4. The device as claimed in claim 3, further comprising an element for detecting the presence of the predetermined condition, the element being configured to measure the voltage at the terminals of the parasitic inductance of one of the electrodes of the transistor other than the control electrode of the transistor.

5. The device as claimed in claim 1, comprising a control resistance interposed between the control electrode of the transistor and the main control circuit, the auxiliary control circuit being arranged so as to inject the auxiliary current into a node interposed between the control resistance and the control electrode of the transistor.

6. The device as claimed in claim 1, the auxiliary control circuit being configured to lock the value of the time derivative of the current flowing between the electrodes of the transistor other than the control electrode around a setpoint value.

7. The device as claimed in claim 4, the auxiliary control circuit comprising:

a first resistance in series between one of the other electrodes of the transistor and a transistor forming part of the element for detecting the presence of the predetermined condition, and

a second resistance in series between said transistor forming part of the element for detecting the presence of the predetermined condition and a voltage source, the terminal of this second resistance connected to the transistor of the element for detecting the presence of the predetermined condition being additionally connected to the control electrode of a transistor through which the auxiliary current flows when the latter is injected,

the locking being achieved by the choice of the value of the ratio between the first and the second resistance.

8. A method for controlling a transistor comprising a control electrode and two other electrodes, by a device comprising, in addition to the transistor:

a main control circuit connected to the control electrode of the transistor and configured to control the state of the transistor in a main operating mode, an auxiliary control circuit and a power amplifier circuit, the method comprising;

injecting, by the auxiliary control circuit, in an auxiliary operating mode, an auxiliary current into the control electrode of the transistor to oppose the current flowing between the main control circuit and the control electrode of the transistor, wherein

the power amplifier circuit, of a “

push-pull”

type, is positioned between the main control circuit and the control electrode of the transistor, the auxiliary control circuit being arranged so that the injected current flows through this power amplifier circuit when the auxiliary operating mode is used,

the auxiliary operating mode being used when a predetermined condition is detected.

9. The method as claimed in claim 8, the predetermined condition relating to the value of the time derivative of the current flowing between the electrodes of the transistor other than the control electrode.

10. The method as claimed in claim 9, the transistor belonging to a branch of a static converter, said arm additionally comprising at least a switching cell in series with the transistor, in which method the predetermined condition makes it possible to determine whether the transistor is cut off when a short circuit has previously developed in the branch.

11. The device as claimed in claim 9, wherein the presence of the predetermined condition is detected by measuring the voltage at the terminals of the parasitic inductance of one of the electrodes of the transistor other than the control electrode.