Inductor current measurement probe

Patent metadata

Field	Value
Publication number	US-2018143264-A1
Application number	US-201715803309-A
Country	US
Kind code	A1
Filing date	Nov 3, 2017
Priority date	Nov 22, 2016
Publication date	May 24, 2018
Grant date	—

Abstract

An inductor current measurement probe apparatus and system are described herein. In an embodiment, a system comprises a probe interconnect including a first connector that couples to a positive terminal of the inductor and a second connector that couples to a negative terminal of the inductor. The system further comprises an RC filter that is coupled to the probe interconnect and that includes at least one resistor and at least one capacitor in an arrangement that converts a voltage of the inductor to a differential capacitor voltage. The system further comprises a differential active probe input circuitry including a positive terminal and a negative terminal that are coupled to the RC filter and arranged to convert the differential capacitor voltage to a single-ended capacitor voltage. In other embodiments, the RC filter may be coupled directly to the inductor. The system may further convert the capacitor voltage to inductor current.

First claim

What is claimed is:

1 . A system for measuring at least one parameter related to an inductor, the system comprising:
a probe interconnect including a first connection that connects to a first terminal of the inductor and a second connection that connects to a second terminal of the inductor; an RC filter that is connected to the probe interconnect and that includes at least one RC network resistor and at least one RC network capacitor in an arrangement that converts a voltage across the inductor to a differential capacitor voltage; and differential probe input circuitry including a first terminal and a second terminal that are connected to the RC filter and arranged to convert the differential capacitor voltage to a single-ended voltage, wherein the single-ended voltage is indicative of the at least one parameter related to the inductor.

2 . The system of claim 1 , wherein the at least one parameter includes a current flowing in the inductor.

3 . The system of claim 1 , further comprising a waveform processor that converts the single-ended voltage to the at least one parameter.

4 . The system of claim 3 , wherein the waveform processor is included in a digital storage oscilloscope.

5 . The system of claim 1 , the system further comprising a compensation resistor.

6 . The system of claim 5 , wherein a compensation capacitor is added across the compensation resistor.

7 . The system of claim 6 , wherein a parallel combination of the compensation resistor and the compensation capacitor are placed between the at least one RC network capacitor and the differential probe input circuitry.

8 . The system of claim 1 , further comprising a ground wire for connection between a measurement reference ground and a device under test (DUT) reference ground.

9 . The system of claim 8 , wherein the DUT reference ground is not connected to earth ground.

10 . The system of claim 1 , wherein the voltage across the inductor is a voltage between a switch node and a non-switched node.

11 . The system of claim 10 , wherein the at least one RC network resistor is connected directly to the switch node.

12 . The system of claim 1 , further comprising a series resistor connected to the at least one RC network capacitor.

13 . The system of claim 12 , further comprising a signal processing element that converts the single-ended voltage to the at least one parameter.

14 . The system of claim 12 , wherein the series resistor is incorporated or inherent within the at least one RC network capacitor.

15 . A method comprising for measuring at least one parameter related to an inductor, the method comprising:
measuring, by a probe interconnector that includes a first connection to a first terminal of the inductor and a second connection to a second terminal of the inductor, a voltage across the inductor; converting, by an RC filter that includes at least one RC network resistor and at least one RC network capacitor, the voltage across the inductor to a differential capacitor voltage; and converting the differential capacitor voltage to a single-ended voltage that is indicative of the at least one parameter related to the inductor.

16 . The method of claim 15 , wherein the at least one parameter includes a current flowing in the inductor, the method further comprising converting the single-ended voltage to the current flowing in the inductor.

17 . The method of claim 15 , further comprising generating and outputting, based on the single-ended voltage, a waveform that represents current flowing in the inductor.

18 . The method of claim 15 , wherein the RC filter further includes a compensation resistor.

19 . The method of claim 18 , the method further comprising adding a compensation capacitor across the compensation resistor.

20 . The method of claim 15 , further comprising connecting a ground wire between a measurement reference ground and a device under test (DUT) reference ground.

Assignees

• Oracle Int Corp

Inventors

• Novak Istvan
• Pupalaikis Peter J
• Jacobs Lawrence W

Classifications

• G01R19/0092

  Measuring current only · CPC title

• G01R31/40 Primary

  Testing power supplies (testing photovoltaic devices H02S50/10) · CPC title

• G01R19/2509

  Details concerning sampling, digitizing or waveform capturing · CPC title

• G01R31/086

  in power transmission or distribution networks, i.e. with interconnected conductors · CPC title

• G01R19/2513 Primary

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title