TMR near-field magnetic communication system

Patent metadata

Field	Value
Publication number	US-10277992-B2
Application number	US-201515326587-A
Country	US
Kind code	B2
Filing date	Jul 7, 2015
Priority date	Jul 14, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

This invention discloses a TMR near-field magnetic communication system, which is used for detecting AC and DC magnetic fields generated by a near-field magnetic communication system, and inputting AC and DC magnetic field signal to an audio electroacoustic taking the same as input signals thereof. The audio electroacoustic device comprises a hearing aid, an earphone of a home entertainment system, a public hearing loop system with an embedded hearing device, etc. The TMR near-field magnetic communication system comprises one or more TMR sensor bridges for detecting AC and DC magnetic field signals, an analog-signal circuit containing a filter which is used for separating components of AC and DC signals output by a TMR sensor, an amplifier which is used for amplifying an AC electrical signal, and an analog output used for transmitting the AC electrical signal to the audio electroacoustic device. The TMR sensor can be a linear or nonlinear TMR sensor, and the TMR sensor is designed to have an optimal signal to noise ratio in a specific DC magnetic field.

First claim

The invention claimed is:

1. A tunneling magnetoresistance (TMR) near-field magnetic communication system used for detecting AC and DC magnetic fields generated by a near-field magnetic communication system, and converting magnetic signals into electrical signals received by an audio electroacoustic device, the TMR near-field magnetic communication system comprising:
a TMR sensor bridge TMR[A] for detecting a magnetic field;
an analog signal circuit connected to an output of the TMR sensor bridge TMR[A], the analog signal circuit comprising a filter and an amplifier, the filter separating AC and DC electrical signals output by the TMR sensor bridge TMR[A], the amplifier amplifying the AC electrical signal, and an analog signal output transmitting the amplified AC electrical signal to the audio electroacoustic device; and
a power circuit connected to the TMR sensor bridge TMR[A] and the analog signal circuit, and a power input for providing power supply for the power circuit;
wherein the TMR sensor bridge TMR[A] is a low-sensitive linear TMR sensor, a high-sensitive linear TMR sensor, or a non-linear TMR sensor.

2. The TMR near-field magnetic communication system according to claim 1 , comprising:
a digital signal circuit connected to the TMR sensor bridge TMR[A], the digital signal circuit processing a DC component of the electrical signal output by the TMR sensor TMR[A]; and
a digital signal output for transmitting information of the DC component output by the TMR sensor bridge TMR[A] to the audio electroacoustic device.

3. The TMR near-field magnetic communication system according to claim 2 ,
wherein the power circuit comprises a duty cycle controller for controlling a high-level duty cycle of the TMR sensor bridge TMR[A];
wherein the digital signal circuit comprises a comparator for detecting the existence of a larger DC electrical signal in the signals output by the TMR sensor bridge TMR[A]; and
wherein, when the comparator detects the larger DC electrical signal in the output of the TMR sensor bridge [A], the duty cycle controller stops working, but an output thereof is still a DC bias voltage.

4. The TMR near-field magnetic communication system according to claim 3 , wherein the power circuit comprises a voltage doubler, and when the comparator detects the larger DC electrical signal in the output of the TMR sensor bridge TMR[A], the voltage doubler is turned on to increase the bias voltage of the TMR sensor bridge TMR[A].

5. The TMR near-field magnetic communication system according to claim 1 , comprising a TMR sensor bridge TMR[B] connected to the power circuit.

6. The TMR near-field magnetic communication system according to claim 5 , comprising:
a digital signal circuit connected to the TMR sensor bridge TMR[B] for processing a DC electrical signal from the TMR sensor bridge TMR[B], the digital signal circuit comprising:
a comparator for detecting a larger DC component in an output of the TMR sensor bridge TMR[B], and when the comparator detects the DC electrical signal in signals output by the TMR sensor bridge TMR[B], the comparator sending a signal to enable the bias voltage of the TMR sensor bridge TMR[A]; and
a digital output for transmitting information of the DC component output by the TMR sensor bridge TMR[B] to the audio electroacoustic device;

wherein the resistance of the TMR sensor bridge TMR[B] being greater than the resistance of the TMR sensor bridge TMR[A].

7. The TMR near-field magnetic communication system according to claim 6 , wherein the power circuit comprises a voltage doubler, and when the comparator detects the DC electrical signal in the output of the TMR sensor bridge TMR[B], the voltage doubler is turned on to increase the bias voltage of the TMR sensor bridge TMR[A].

8. The TMR near-field magnetic communication system according to claim 5 , comprising a TMR sensor bridge TMR[C], the TMR sensor bridge TMR[C] and the TMR sensor TMR[B] respectively detecting two magnetic field components in directions perpendicular to each other, and the TMR sensor TMR[C] being a high-sensitive linear TMR sensor for detecting the AC magnetic field.

9. The TMR near-field magnetic communication system according to claim 8 , wherein the analog signal circuit is connected to an output of the TMR sensor bridge TMR[C], the analog signal circuit separates and amplifies an AC electrical signal output by the TMR sensor bridge TMR[C], and transmits the processed AC electrical signal to the analog signal output of the TMR near-field magnetic communication system.

10. The TMR near-field magnetic communication system according to claim 1 , wherein the TMR sensor bridge TMR[A] and the TMR sensor bridge TMR[B] are half bridges, full bridges, push-pull bridges, or any combination thereof; the TMR near-field magnetic communication system is packaged into a chip-on-flex package, a multi-chip package, or a chip-on-board package; and the TMR sensor bridge TMR[A] and the TMR sensor bridge TMR[B] are manufactured by using a flip die process.

11. The TMR near-field magnetic communication system according to claim 8 , wherein the TMR sensor bridge is a half bridge, a full bridge, a push-pull bridge, or any combination thereof; the TMR near-field magnetic communication system is packaged into a chip-on-flex package, a multi-chip package, or a chip-on-board package; and the TMR sensor bridge is manufactured by using a flip die process.

12. The TMR near-field magnetic communication system according to claim 10 , wherein the TMR sensor bridge TMR[A] is a non-linear TMR sensor manufactured by using a flip die process, a bias magnetic field of each bridge arm is greater than a saturation magnetic field thereof, and a sum of the bias magnetic field and the saturation magnetic field is equal to the maximum DC magnetic field operated by the TMR sensor bridge TMR[A].

13. The TMR near-field magnetic communication system according to claim 11 , wherein the TMR sensor bridge TMR[A] is a non-linear TMR sensor manufactured by using a flip die process, a bias magnetic field of each bridge arm is greater than a saturation magnetic field thereof, and a sum of the bias magnetic field and the saturation magnetic field is equal to the maximum DC magnetic field operated by the TMR sensor bridge TMR[A].

14. The TMR near-field magnetic communication according to claim 1 , comprising a digital input for manually switching the TMR near-field magnetic communication system between a hearing loop system mode, a T-coil mode, and a standby mode, wherein in the standby mode, the TMR sensor bridge TMR[A] does not work.

15. The TMR near-field magnetic communication system according to claim 8 , comprising a digital input for manually switching the TMR near-field magnetic communication system between a hearing loop system mode, a T-coil mode, and a standby mode, wherein, in the standby mode, the TMR sensor bridge TMR[A] does not work.

16. The TMR near-field magnetic communication system according to claim 1 , comprising a TMR sensor bridge TMR[C], the TMR sensor bridge TMR[C] and the TMR sensor bridge TMR[A] respectively detecting components of two magnetic fields perpendicular to each other, the TMR sensor TMR[C] being a high-sensitive linear TMR sensor for detecting an AC magnetic field, and an output of the TMR sensor bridge TMR[C] being buffered and AC-coupled to the audio amplifier in the analog signal circuit.

17. The TMR near-field magnetic communication system according to claim 16 , comprising a digital signal circuit, the digital signal circuit comprising a comparator, the comparator receiving a DC ele

Assignees

• Multidimension Technology Co Ltd

Inventors

• Deak James Geza
• Guo Haiping
• Xue Songsheng

Classifications

• H04R25/00

  Electric hearing aids · CPC title

• H04W4/80

  Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication · CPC title

• G01R33/098 Primary

  comprising tunnel junctions, e.g. tunnel magnetoresistance sensors · CPC title

• H04R25/554 Primary

  using a wireless connection, e.g. between microphone and amplifier or using Tcoils · CPC title

• H04R25/305

  Self-monitoring or self-testing · CPC title