Methods and apparatus for sensor diagnostics

Patent metadata

Field	Value
Publication number	US-10488458-B2
Application number	US-201414578800-A
Country	US
Kind code	B2
Filing date	Dec 22, 2014
Priority date	Dec 26, 2013
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

Methods and apparatus for providing an integrated circuit having a drive current source, a magnetic sensing element coupled to the drive current source, the magnetic sensing element having first and second differential outputs, and first and second current elements to provide respective currents in relation to the drive current source, wherein the first current element is coupled to the first differential output and the second current element is coupled to the second differential output. In illustrative embodiments, an IC output can output a voltage corresponding to the currents of the first and second current elements.

First claim

What is claimed is:

1. An integrated circuit, comprising:
a drive current source having a drive current;
a magnetic sensing element coupled to the drive current source, the magnetic sensing element having first and second differential outputs;
first and second current elements to provide respective first and second currents in proportion to a constant K to the drive current, wherein the magnetic sensing element is coupled to the first and second current elements, wherein the first current element provides the first current flowing into the first differential output and the second current element receives the second current flowing from the second differential output, wherein the drive current source, the first current element, the first differential output, the second differential output, and the second current element form a series circuit path loop, wherein the first and second current elements comprise respective current replicators;
an amplifier configured to receive the first and second differential outputs of the magnetic sensing element; and
an IC output to receive an output of the amplifier and to output a voltage corresponding to the first current into the first differential output, the second current from the second differential output, and the drive current into the magnetic sensing element.

2. The integrated circuit according to claim 1 , wherein the magnetic sensing element comprises a Hall element.

3. The integrated circuit according to claim 1 , wherein the magnetic sensing element comprises a magnetoresistive element.

4. The integrated circuit according to claim 1 , further including a signal path that includes a voltage divider having a first resistive element, a second resistive element, and third resistive element coupled in series, wherein the second resistive element comprises the magnetic sensing element.

5. The integrated circuit according to claim 1 , wherein the integrated circuit provides an output voltage on the IC output that is proportional to an applied magnetic field.

6. A method, comprising:
employing a drive current source;
coupling a magnetic sensing element to the drive current source, the magnetic sensing element having first and second differential outputs;
employing first and second current elements to provide respective first and second currents in proportion to a constant K to the drive current, wherein the magnetic sensing element is coupled to the first and second current elements, wherein the first current element provides the first current flowing into the first differential output and the second current element receives the second current flowing from the second differential output, wherein the drive current source, the first current element, the first differential output, the second differential output, and the second current element form a series circuit path loop, wherein the first and second current elements comprise respective current replicators;
employing an amplifier configured to receive the first and second differential outputs of the magnetic sensing element and
providing an IC output to receive an output of the amplifier and to output a voltage corresponding to the first current into the first differential output, the second current from the second differential output, and the drive current into the magnetic sensing element.

7. The method according to claim 6 , wherein the magnetic sensing element comprises a Hall element.

8. The method according to claim 6 , wherein the magnetic sensing element comprises a magnetoresistive element.

9. The method according to claim 6 , further including a signal path that includes a voltage divider having a first resistive element, a second resistive element, and third resistive element coupled in series, wherein the second resistive element comprises the magnetic sensing element.

10. The method according to claim 6 , wherein the integrated circuit provides an output voltage on the IC output that is proportional to an applied magnetic field.

Assignees

• Allegro Microsystems Llc

Inventors

• Milano Shaun D
• El Bacha Georges
• Doogue Michael C
• Haas David J
• Delmain Gregory
• Gaboury Michael
• Taylor William P

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• G01R31/2884 Primary

  using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence) · CPC title

• G01R31/3187

  Built-in tests · CPC title

• G01R33/0023 Primary

  Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration (G01R33/0017 takes precedence) · CPC title