Circuit for an active diode and method for operating an active diode

Patent metadata

Field	Value
Publication number	US-9577629-B2
Application number	US-23948208-A
Country	US
Kind code	B2
Filing date	Sep 26, 2008
Priority date	Sep 28, 2007
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

Embodiments of the invention relate to a circuit for an active diode, a method for operating an active diode, and, based thereon, an integrated active diode system, a rectifier, and a system for voltage conversion and/or regulation, comprising at least one transistor by which a current defined as positive from a first connection to a second connection of the transistor can be controlled, and at least one measuring/control circuit (for determining the current by means of which the at least one transistor can be switched on for currents under and at most up to a predetermined, non-positive threshold value (i1<=ith<=0), and can otherwise be switched off.

First claim

What is claimed is:

1. A circuit comprising:
at least one transistor, wherein a current that flows from a first connection to a second connection of the transistor can be controlled;
at least one first measuring/control circuit for determining the current and causing the at least one transistor to be switched on when the current is below and at most up to a predetermined, non-positive threshold value, and otherwise to be switched off when the current is above the predetermined, non-positive threshold value, wherein the at least one first measuring/control circuit comprises
a current input coupled to the at least one transistor, and
an amplifier having an amplifier input, an amplifier output, and a resistance coupled between the amplifier input and the amplifier output, the amplifier output producing an output signal that is inverted with respect to the amplifier input; and

a second measuring/control circuit parallel to the at least one first measuring/control circuit, the second measuring/control circuit comprising a second amplifier to amplify at least a portion of the current input into the at least one first measuring/control circuit, the second amplifier connected to a gate of a shutdown device for switching off the at least one transistor faster than the at least one first measuring/control circuit in case of an emergency if the current is a positive current of an opposite polarity of the non-positive threshold value.

2. The circuit according to claim 1 , wherein:
the at least one transistor comprises a first transistor and the current comprises a first current;
the circuit further comprises at least one second transistor for mirroring the first current in a second current; and
wherein the at least one first measuring/control circuit measures the second current and generates a control signal, wherein control connections of the at least one transistor and the second transistor can be controlled by the control signal such that the at least one transistor and the at least one second transistor are switched on when the current is below and at most up to a predetermined, non-positive threshold value, and otherwise to be switched off.

3. The circuit according to claim 2 , wherein the at least one transistor, the at least one second transistor and the at least one first measuring/control circuit are monolithically integrated on a single substrate.

4. The circuit according to claim 2 , wherein the at least one transistor and the at least one second transistor comprise transistors selected from the group consisting of n-channel MOSFET transistors, planar MOSFET transistors, trench MOSFET transistors, field-plate trench MOSFET transistors, superjunction transistors, p-channel MOSFET transistors, bipolar transistors and Insulated Gate Bipolar Transistors (IGBTs).

5. The circuit according to claim 3 , wherein the at least one transistor and the at least one second transistor each comprise a plurality of individual transistor cells with spatially separated gates and source regions.

6. The circuit according to claim 3 , wherein the at least one transistor and the at least one second transistor correspond to each other in their structures.

7. The circuit according to claim 3 , wherein the first connection of the at least one transistor and a first connection of the at least one second transistor comprise a joint drain region.

8. The circuit according to claim 3 , wherein the second connection of the at least one transistor and a second connection of the at least one second transistor comprise n+-doped regions in p-doped wells, and wherein the control connections of the at least one transistor and the at least one second transistor comprise planar or vertical gates in whose regions the p-doped wells are separated from each other.

9. The circuit according to claim 3 , wherein the at least one first measuring/control circuit comprises at least one operational amplifier.

10. The circuit according to claim 3 , wherein the at least one first measuring/control circuit comprises at least one driver-compatible p-channel MOSFET transistor for controlling the control connection of the at least one transistor.

11. The circuit according to claim 10 , wherein the circuit comprises a rectifier comprising at least one active diode.

12. An integrated active diode system comprising:
at least one MOSFET transistor wherein a current flows between a source connection and a drain connection of the at least one MOSFET transistor;
a first external connection that is coupled to the drain connection of the at least one MOSFET transistor;
a second external connection that is coupled to the source connection of the at least one MOSFET transistor;
a first measuring/control circuit for determining the current and causing the at least one MOSFET transistor to be switched on when the current is below and at most up to a predetermined, non-positive threshold value, and otherwise to be switched off, wherein the first measuring/control circuit comprises
a current input coupled to the at least one MOSFET transistor, and
an amplifier having a first amplifier input, a second amplifier input, an amplifier output, and a resistance coupled between the first amplifier input and the amplifier output, the amplifier output producing an output signal that is inverted with respect to the first amplifier input;

a second measuring/control circuit parallel to the first measuring/control circuit, the second measuring/control circuit comprising a second amplifier to amplify at least a portion of the current input into the first measuring/control circuit, the second amplifier connected to a gate of a shutdown MOSFET for switching off the at least one MOSFET transistor faster than the first measuring/control circuit in case of an emergency if the current is a positive current of an opposite polarity of the non-positive threshold value; and
a third external connection that is coupled to the second amplifier input of the first measuring/control circuit.

13. The integrated active diode system according to claim 12 , wherein the integrated active diode system comprises a rectifier.

14. A system for voltage conversion and/or regulation with at least one rectifier according to claim 13 .

15. A method for operating an active diode in the form of at least one transistor, the method comprising:
determining a first current defined as positive from a first connection to a second connection of a transistor, determining comprising
mirroring the first current in a second current with a second transistor;
measuring the second current with a first circuit comprising an inverting amplifier having an input coupled to a current measurement input and a resistance coupled between an output of the inverting amplifier and the input of the inverting amplifier;

controlling the transistor, controlling comprising
switching on the transistor when the current is below and at most up to a predetermined non-positive threshold value,
switching-off the transistor when the current is above the predetermined non-positive threshold value, and
generating a control signal related to the second current; and

shutting-off the transistor at a turn-off rate that is faster than the step of switching-off the transistor if the first current is a positive current of an opposite polarity of the non-positive threshold value, shutting-off the transistor comprising using a second circuit comprising a second amplifier having an output coupled to a gate of a shutdown MOSFET to amplify at least a portion of the first current to produce an amplified signal, and switching off the transistor using the amplified si

Assignees

• Deboy Gerald
• Infineon Technologies Austria Ag

Inventors

• Deboy Gerald

Classifications

• H03K17/302

  in field-effect transistor switches · CPC title

• H03K17/166 Primary

  Soft switching · CPC title