METHOD AND APPARATUS FOR HIGH CURRENT MEASUREMENT

• US 20090284248A1
• Filed: 05/15/2008
• Published: 11/19/2009
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Etter, Brett E., Alfano, Donald E., Dupuis, Timothy J., Coffey, Donald K.
• Granted Patent: US 7,728,578 B2
• Time in Patent Office: Days
• US Class Current: 324/126
• CPC Class Codes: G01R 1/203 Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R
• CPC Class Codes: G01R 15/181 using coils without a magnetic core, e.g. Rogowski coils

Abstract

In order to extend the measurement range of a current sensor, a current divider is formed by a first conductor formed in a current sensor that is mounted on a printed circuit board and a second conductor on the printed circuit board that electrically shorts at least one input terminal of the current sensor to at least one output terminal of the current sensor. The input terminal of the current sensor supplies the current to be measured to the first conductor and the output terminal supplies the measured current back to the printed circuit board.

Claims

1. An apparatus comprises:

a printed circuit board;

a current sensor coupled to the printed circuit board, the current sensor including a first conductor portion to carry a first current to be measured by the current sensor;

a second conductor portion to carry a second current;

wherein the first conductor portion and the second conductor portion form a current divider to divide a third current.

2. The apparatus as recited in claim 1 wherein the current sensor further comprises:

one or more input terminals to receive the first current from the PCB and one or more output terminals to supply the first current to the PCB; and

wherein the second conductor is electrically coupled to at least one of the one or more input terminals and at least one of the one or more output terminals.

3. The apparatus as recited in claim 1, wherein the third current is larger than the first current.

4. The apparatus as recited in claim 1, wherein the first current is from about 1 to about 20 A.

5. The apparatus as recited in claim 1, wherein the second conductor is a conductive trace on the printed circuit board.

6. The apparatus as recited in claim 1, wherein the first and second conductor portions are formed of a substantially similar conductive material.

7. The apparatus as recited in claim 6, wherein the first and second conductor portions are formed substantially of copper.

8. The apparatus as recited in claim 1 wherein the first and second current combine into a third current of from about 30A to about 100A.

9. The apparatus as recited in claim 1 wherein the current sensor includes a package in which the first conductor portion is formed.

10. A method for measuring a current comprising:

dividing a first current in a current divider formed by a first conductor of a current sensor and a second conductor of a printed circuit board, the first conductor receiving current from at least one input terminal of the current sensor and supplying current to at least one output terminal of the current sensor, the second conductor coupling the at least one input terminal and the at least one output terminal of the current sensor; and

measuring a second current in the first conductor of the current sensor formed by the current division.

11. The method as recited in claim 10 further comprising adjusting the measured current to reflect the current divider.

12. The method as recited in claim 10, wherein the first current is larger than the second current by at least about 60 percent.

13. The method as recited in claim 10, wherein the first current is from about 1 to about 20A.

14. The method as recited in claim 10 wherein the first current is from about 30A to about 100A.

15. An apparatus comprising:

a current divider formed by a first conductor in a current sensor and a second conductor on a printed circuit board that electrically shorts at least one input terminal of the current sensor to at least one output terminal of the current sensor.

16. The apparatus as recited in claim 15, wherein the at least one input terminal of the current sensor is coupled to supply current to be measured to the first conductor and the at least one output terminal is coupled to supply the measured current to the printed circuit board.

17. The apparatus as recited in claim 15 wherein the current sensor further comprises:

an integrated circuit die; and

a package in which the first conductor is formed adjacent to the integrated circuit die.

18. The apparatus as recited in claim 15, wherein the first and second conductors are formed of a substantially similar conductive material.

19. The apparatus as recited in claim 15, wherein the first and second conductors are formed substantially of copper.