Current sensor, system and method

Patent metadata

Field	Value
Publication number	US-2016291059-A1
Application number	US-201615080747-A
Country	US
Kind code	A1
Filing date	Mar 25, 2016
Priority date	Apr 1, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

Current sensors, systems and methods are provided. A test current is injected via a pair of force terminals into a conductor and a pair of sense terminals are configured to provide an input signal that corresponds to a voltage drop across the conductor. Based on the test current in the conductor and based on the input signal, a contribution to the voltage drop due to the test current and a contribution to the voltage drop due to a primary current through the conductor may be determined. In addition, at least one of a reference resistance of the conductor and the primary current in the conductor may be further determined.

First claim

What is claimed is:

1 . A system, comprising:
a conductor; at least one first electrical contact coupled to the conductor at a first position; at least one second electrical contact coupled to the conductor at a second position, the first position and the second position being arranged at a distance with respect to each other; and a pair of force terminals configured to inject, via the at least one first electrical contact and the at least one second electrical contact, a test current into the conductor; and a device, comprising:
a microelectronic package;
a memory configured to store a predefined reference resistance associated with the conductor;
a pair of sense terminals configured to provide an input signal related to a voltage drop across the conductor between the at least one first electrical contact and the at least one second electrical contact, wherein the pair of sense terminals is at least partly accessible from outside the microelectronic package; and
at least one processor configured to determine a primary current through the conductor based on the input signal and the predefined reference resistance.

2 . The system of claim 1 , further comprising:
wiring coupling a first one of the pair of sense terminals and a first one of the pair of force terminals with the at least one first electrical contact and further coupling a second one of the pair of sense terminals and a second one of the pair of force terminals with the at least one second electrical contact.

3 . The system of claim 2 , further comprising a plurality of first electrical contacts and a plurality of second electrical contacts,
wherein the wiring couples a first one of the plurality of first electrical contacts with a first one of the pair of sense terminals, wherein the wiring couples a first one of the plurality of second electrical contacts with a second one of the pair of sense terminals, wherein the wiring couples a second one of the plurality of first electrical contacts with a first one of the pair of force terminals, wherein the wiring couples a second one of the plurality of second electrical contacts with a second one of the pair of force terminals.

4 . The system of claim 2 , wherein the wiring comprises a common connector coupling a first one of the pair of sense terminals and a first one of the pair of force terminals with the at least one first electrical contact.

5 . The system of claim 1 , further comprising a substrate having a first conductive layer and a second conductive layer, the second conductive layer contiguously forming the conductor in-between the first position and the second position.

6 . The system of claim 5 , wherein the first conductive layer has a first thickness and the second conductive layer has a second thickness, wherein the first thickness is less than the second thickness,
wherein the wiring comprises traces in the first conductive layer.

7 . The system of claim 5 , wherein the microelectronic package is attached to an outer surface of the substrate adjacent to the second conductive layer, and the substrate further comprises a thermal coupling between the second conductive layer forming the conductor and the outer surface.

8 . A device, comprising:
a microelectronic package; a pair of sense terminals configured to provide an input signal related to a voltage drop across a conductor; and at least one processor configured to determine, based on a test current in the conductor and based on the input signal, a contribution to the voltage drop due to the test current, to determine a contribution to the voltage drop due to a primary current through the conductor, and to determine the primary current.

9 . The device of claim 8 , further comprising a pair of force terminals configured to inject the test current into the conductor.

10 . The device of claim 8 , further comprising:
a temperature sensor configured to measure a temperature signal indicative of a temperature, wherein the at least one processor is configured to determine the primary current based on the temperature signal.

11 . The device of claim 10 , wherein the temperature sensor is arranged in the microelectronic package such that a sensitive region of the temperature sensor is thermally coupled with an exterior of the microelectronic package.

12 . The device of claim 8 , further comprising:
a control interface configured to receive a control signal indicating a current transient of the primary current, wherein the pair of sense terminals is configured to selectively provide the input signal depending on the received control signal.

13 . The device of claim 12 , further comprising a protection circuit configured to suppress a transient of the input signal based on the received control signal and includes at least one of a series-connected capacitor, a galvanically isolated inductive coupling, a series-connected resistor, and a clamping diode.

14 . The device of claim 8 , further comprising:
a current source coupled to the pair of force terminals and configured to generate the test current.

15 . A method, comprising:
injecting, via a pair of force terminals, a test current into a conductor; receiving, via a pair of sense terminals, an input signal related to a voltage drop across the conductor; determining, via at least one processor, based on the test current and the input signal, a contribution to the voltage drop due to the test current; determining, via the at least one processor, a contribution to the voltage drop due to a primary current; and determining, via the at least one processor, at least one of a reference resistance of the conductor and the primary current.

16 . The method of claim 15 ,
wherein determining the at least one of the reference resistance of the conductor and the primary current is executed at a plurality of temperatures, and wherein the determined reference resistance includes a temperature coefficient of resistivity.

17 . The method of claim 15 , further comprising:
writing, to a memory, the reference resistance of the conductor.

18 . The method of claim 15 ,
wherein the test current is injected into the conductor having a spectral distribution, and wherein said determining of the contribution to the voltage drop due to the test current is based on at least one of a lock-in technique and a spread-spectrum technique sensitive to the spectral distribution of the test current.

19 . The method of claim 18 , wherein the spectral distribution resides in a frequency band of 0 Hz-1 MHz.

20 . The method of claim 15 , wherein the test current is selectively injected into the conductor in intermitted time intervals.

21 . The method of claim 15 , wherein the test current comprises an alternating current.

22 . The method of claim 15 , wherein the test current is injected into the conductor via at least one first electrical contact coupled to the conductor at a first position and via at least one second electrical contact coupled to the conductor at a second position, the first position and the second position being arranged at a distance with respect to each other, wherein the input signal corresponds to the voltage drop across the conductor between the at least one first position and the at least one second position.

Assignees

• Infineon Technologies Ag

Inventors

• Ausserlechner Udo

Classifications

• G01R15/146 Primary

  Measuring arrangements for current not covered by other subgroups of G01R15/14, e.g. using current dividers, shunts, or measuring a voltage drop (if no voltage isolation is involved G01R1/203 or G01R19/0092) · CPC title

• G01R19/32 Primary

  Compensating for temperature change · CPC title

• G01R27/08

  Measuring resistance by measuring both voltage and current · CPC title

• G01R1/203

  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 title

• G01R27/16

  Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line · CPC title