Voltage isolation buffer with hall effect magnetic field sensor

• US 6,879,145 B1
• Filed: 02/15/2002
• Issued: 04/12/2005
• Est. Priority Date: 02/15/2002
• Status: Active Grant

• Current Assignee: OL Security LLC (Intellectual Ventures LLC)
• Original Assignee: Larry L. Harris
• Inventors: Harris, Larry L.
• Primary Examiner(s): Nguyen, Vinh P.
• Application Number:
  US10/076,951
• Time in Patent Office: 1,152 Days
• Field of Search: 324/117.R, 324/117.H, 324/126, 324/127, 324251-252, 324/73.1, 324/158.1
• US Class Current: 324/117.00H
• CPC Class Codes: G01D 18/006 Intermittent recalibration
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown

Abstract

A voltage isolation buffer, comprising a pilot channel having a first Hall effect element and a data channel having a second Hall effect element is disclosed. The pilot channel is preferably AC coupled, and the data channel is preferably DC coupled. The voltage isolation buffer may comprise a means for calibration, which may be configurable to calibrate the voltage generated by the second Hall effect element based on the information from the first Hall effect element. A bi-directional voltage isolation buffer is also disclosed, comprising a first integrated circuit and a second integrated circuit. The first integrated circuit comprises a DC coupled Hall effect sensor and an AC coupled Hall effect sensor. The second integrated circuit comprises an AC coupled Hall effect sensor and a DC coupled Hall effect sensor. A method for transmitting data across a voltage isolation barrier is also disclosed comprising the steps of generating a first Hall voltage signal, AC coupling the first Hall voltage signal, generating a second Hall voltage signal, DC coupling the second Hall voltage signal, and calibrating the second Hall voltage signal, wherein the step of calibrating is controlled by the first Hall voltage signal.

Claims

1. A voltage isolation buffer, comprising:

a pilot channel comprising a first Hall effect element;

a data channel comprising a second Hall effect element; and

a means for calibration operatively coupled to the second Hall effect element;

wherein the pilot channel is operatively coupled to the data channel;

wherein first hall effect element is AC coupled.

2. The voltage isolation buffer of claim 1, wherein the second Hall effect element is DC coupled.

3. The voltage isolation buffer of claim 2, wherein the first Hall effect element is composed of semiconductive material.

4. The voltage isolation buffer of claim 3, wherein the first Hall effect element is composed of silicon.

5. The voltage isolation buffer of claim 2, wherein the second Hall effect element is composed of semiconductive material.

6. The voltage isolation buffer of claim 5, wherein the second Hall effect element is composed of silicon.

7. The voltage isolation buffer of claim 1, wherein the means for calibration is operatively coupled to the first Hall effect element.

8. The voltage isolation buffer of claim 7, wherein the means for calibration is configurable to receive information from the first Hall effect element.

9. The voltage isolation buffer of claim 8, wherein the means for calibration is configurable to calibrate the voltage generated by the second Hall effect element based on the information from the first Hall effect element.

10. The voltage isolation buffer of claim 1, wherein the pilot channel further comprises a first comparator operatively coupled to the means for calibration.

11. The voltage isolation buffer of claim 10, wherein the pilot channel further comprises a band-pass filter operatively coupled to the first comparator.

12. The voltage isolation buffer of claim 11, wherein the pilot channel further comprises an amplifier operatively coupled to the band-pass filter.

13. The voltage isolation buffer of claim 10, wherein the data channel further comprises a second comparator operatively coupled to the means for calibration.

14. A voltage isolation buffer, comprising:

a pilot channel comprising an AC coupled Hall effect sensor; and

a data channel comprising a DC coupled Hall effect sensor, and further comprising a means for calibration operatively coupled to the AC coupled Hall effect sensor;

wherein the voltage isolation buffer allows data to be transmitted across the voltage isolation buffer via a magnetic field; and

wherein the means for calibration is operatively coupled to the DC coupled Hall effect sensor; and

wherein the means for calibration is configurable to receive information from the AC coupled Hall effect sensor; and

wherein the means for calibration is configurable to calibrate the DC coupled Hall effect sensor based on the information from the AC coupled Hall effect sensor.

15. The voltage isolation buffer of claim 14, wherein the pilot channel further comprises a first comparator operatively coupled to the means for calibration.

16. The voltage isolation buffer of claim 15, wherein the pilot channel further comprises a band-pass filter operatively coupled to the first comparator.

17. The voltage isolation buffer of claim 16, wherein the pilot channel further comprises an amplifier operatively coupled to the band-pass filter.

18. The voltage isolation buffer of claim 15, wherein the data channel further comprises a second comparator operatively coupled to the means for calibration.

19. An integrated circuit comprising:

an AC coupled Hall effect sensor;

a DC coupled Hall effect sensor; and

a means for calibration coupled to the DC coupled Hall effect sensor;

wherein the AC coupled Hall effect sensor is operatively coupled to the DC coupled Hall effect sensor.

20. A method for transmitting data across a voltage isolation barrier, the method comprising the steps of:

generating a first Hall voltage signal;

AC coupling the first Hall voltage signal;

generating a second Hall voltage signal;

DC coupling the second Hall voltage signal; and

calibrating the second Hall voltage signal;

wherein the step of calibrating is controlled by the first Hall voltage signal.

21. The method of claim 20, further comprising the step of amplifying the first Hall voltage signal.

22. The method of claim 20, further comprising the step of amplifying the second Hall voltage signal.

23. The method of claim 20, further comprising the step of converting the first Hall voltage signal from an analog signal to a digital signal.

24. The method of claim 20, further comprising the step of converting the second Hall voltage signal from an analog signal to a digital signal.