Electronic Circuit with a Reverse Conducting Transistor Device

• US 20140091839A1
• Filed: 09/28/2012
• Published: 04/03/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Peters, Dethard, Siemieniec, Ralf, Friedrichs, Peter
• Granted Patent: US 8,854,087 B2
• Time in Patent Office: Days
• US Class Current: 327/109
• CPC Class Codes: H01L 27/085 including field-effect components only
• CPC Class Codes: H01L 27/098 the components being PN junction gate field-effect transistors
• CPC Class Codes: H01L 29/1066 Gate region of field-effect devices with PN junction gate
• CPC Class Codes: H01L 29/42316 for field-effect transistors
• CPC Class Codes: H01L 29/8083 Vertical transistors SIT H01L29/7722
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 2017/307 circuits simulating a diode, e.g. threshold zero

Abstract

An electronic circuit includes a first transistor device with a control terminal and a load path. A drive circuit includes an input terminal and an output terminal. The output terminal is coupled to the control terminal of the first transistor device. The drive circuit is operable to drive the first transistor device dependent on an input signal received at the input terminal. A polarity detector is coupled in parallel with the load path of the first transistor device. The polarity detector includes a second transistor device and a current detector. The second transistor device includes a load path connected to the load path of the first transistor device. The current detector includes a sense path in series with the load path of the second transistor device and an output connected to the input terminal of the drive circuit.

Claims

1. An electronic circuit, comprising:

a first transistor device comprising a control terminal and a load path;

a drive circuit comprising an input terminal and an output terminal, the output terminal coupled to the control terminal of the first transistor device and the drive circuit operable to drive the first transistor device dependent on an input signal received at the input terminal; and

a polarity detector coupled in parallel with the load path of the first transistor device, the polarity detector comprising a second transistor device and a current detector, wherein

the second transistor device comprises a load path coupled to the load path of the first transistor device, and

the current detector comprises a sense path in series with the load path of the second transistor device and an output coupled to the input terminal of the drive circuit, the current detector operable to detect a current direction of a current through the second transistor device, to generate an on-level of the input signal when the current through the second transistor device has a predefined current direction, and not to affect a signal level of the input signal when the current through the second transistor has a current direction opposite the predefined current direction.

2. The electronic circuit of claim 1, wherein the second transistor device further comprises a control terminal coupled to the load path of the second transistor device.

3. The electronic circuit of claim 1, wherein the first transistor device and the second transistor device are transistors of the same transistor type.

4. The electronic circuit of claim 3, wherein the first transistor device is a JFET and the second transistor device is a JFET.

5. The electronic circuit of claim 4, wherein the first transistor device is an n-type JFET and the second transistor device is an n-type JFET.

6. The electronic circuit of claim 3, wherein the first transistor device is a HEMT and wherein the second transistor device is a HEMT.

7. The electronic circuit of claim 5,

wherein both the first transistor device and the second transistor device comprise a gate terminal, a source terminal and a drain terminal;

and

wherein the gate terminal of the second transistor device is coupled to the source terminal of the second transistor device and wherein the drain terminal of the second transistor device is coupled to the drain terminal of the first transistor device.

8. The electronic circuit of claim 1, wherein the first transistor device and the second transistor device are integrated in a common semiconductor body.

9. The electronic circuit of claim 1, wherein the current detector comprises a third transistor device with a control current path and a load current path, the control current path coupled in series with the load path of the second transistor device and the load current path coupled between the input terminal of the drive circuit and a terminal for an on-level.

10. The electronic circuit of claim 9, wherein the terminal for the on-level is a first load terminal of the first transistor device or a terminal of a voltage source coupled to the first load terminal of the first transistor device.

11. The electronic circuit of claim 9,

wherein the third transistor device is a bipolar junction transistor;

and

wherein the control current path is a base-emitter path and the load current path is a collector-emitter path of the bipolar junction transistor.

12. The electronic circuit of claim 11, wherein the bipolar junction transistor is a PNP transistor.

13. A method of operating an electronic circuit, the method comprising:

switching a conduction transistor with a first conduction path on and off in order to control current flowing in a first direction through the first conduction path using a drive circuit;

detecting a reverse polarity in the first conduction path using a polarity detector, wherein the polarity detector has a second conduction path in parallel with the first conduction path; and

overriding an input to the drive circuit to switch the conduction transistor on when a reverse polarity is detected, wherein the reverse polarity comprises a voltage opposite to a voltage inducing the current flowing in the first direction.

14. The method of claim 13, wherein the method further comprises conducting a current in a second direction through the first conduction path when the input to the drive circuit is overridden.

15. The method of claim 13, wherein the polarity detector comprises a second transistor coupled in series with a current detector, and wherein the current detector is configured to detect the reverse polarity and override the input to the drive circuit.

16. An electronic circuit comprising:

a first transistor comprising a gate, a first conduction terminal coupled to a first load terminal, and a second conduction terminal coupled to a second load terminal;

a drive circuit comprising an input terminal configured to receive a control signal from a control circuit and an output terminal coupled to the gate of the first transistor;

a second transistor comprising a first conduction terminal coupled to the first conduction terminal of the first transistor, a second conduction terminal, and a gate coupled to the second conduction terminal; and

a current detector comprising a first conduction terminal coupled to the second conduction terminal of the second transistor, a second conduction terminal coupled to the second conduction terminal of the first transistor, and a control signal terminal coupled to the input terminal of the drive circuit.

17. The electronic circuit of claim 16, wherein the drive circuit comprises a third transistor and a fourth transistor, wherein control terminals of the third transistor and the fourth transistor are coupled to the input terminal of the drive circuit and conduction paths of the third transistor and the fourth transistor are coupled in series between a first supply voltage and a second supply voltage.

18. The electronic circuit of claim 16, wherein the current detector comprises a bipolar junction transistor (BJT) having a primary conduction path coupled between the input terminal of the drive circuit and a reference voltage and having a base terminal coupled to the second conduction terminal of the second transistor.

19. The electronic circuit of claim 18, wherein the BJT of the current detector has an emitter coupled to the reference voltage and a collector coupled to the input terminal of the drive circuit.

20. The electronic circuit of claim 16, wherein the first and second transistors are JFETs.

21. The electronic circuit of claim 16, wherein first and the second transistors are integrated in a common semiconductor body.

22. An electronic circuit, comprising:

a first transistor device comprising a control terminal and a load path;

a drive circuit comprising an input terminal and an output terminal, the output terminal coupled to the control terminal of the first transistor device and the drive circuit operable to drive the first transistor device dependent on an input signal received at the input terminal; and

a polarity detector coupled in parallel with the load path of the first transistor device, the polarity detector comprising a second transistor device and a current detector, wherein

the second transistor device comprises a load path coupled to the load path of the first transistor device and a control terminal electrically coupled to the load path of the second transistor device, and

the current detector comprises a sense path in series with the load path of the second transistor device and an output coupled to the input terminal of the drive circuit, the current detector operable to generate an on-level of the input signal when a current through the second transistor device has a predefined current direction.