Push-pull flipped-die half-bridge magnetoresistive switch

Patent metadata

Field	Value
Publication number	US-9739850-B2
Application number	US-201414781877-A
Country	US
Kind code	B2
Filing date	Apr 1, 2014
Priority date	Apr 1, 2013
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

Push-pull half-bridge magnetoresistive switch, comprising two magnetic sensor chips, each magnetic sensor chip having a magnetic induction resistor and a magnetic induction resistor electrical connection pad. The two magnetic sensor chips are electrically interconnected and have opposite and parallel directions of induction, thus forming the push-pull half-bridge circuit. The magnetic induction resistor comprises one or a plurality of magnetoresistive elements connected in series. The magnetic induction resistor pads are located at adjacent edges of the magnetic sensor chips, and each pad may accommodate the welding of at least two bonding wires. The magnetoresistive switch may improve the sensitivity of a sensor, and decrease output voltage deviation and output voltage temperature drift, which is beneficial for decreasing the volume and increasing the performance of the switch sensor.

First claim

The invention claimed is:

1. A push-pull half-bridge magnetoresistive switch sensor, comprising:
a case;
a leadframe-based chip paddle with a protrusion to form a ground terminal extending from inside to outside of the case, a first pin to form a VCC terminal extending from inside to outside of the case, and a second pin to form an output terminal extending from inside to outside of the case;
two magnetic sensor chips within the case, including a first magnetoresistive sensor chip with at least one magnetoresistive element and a first pinned layer magnetization vector and a second magnetoresistive sensor chip with at least one magnetoresistive element and a second pinned layer magnetization vector, the first and second magnetoresistive sensor chips being attached to the chip paddle and arranged for the first and second pinned layer magnetization vectors to be at a 180 degree rotational angle relative to each other, wherein each of the magnetic sensor chips has bond pads adjacent to magnetic sensor chip edges for electrical connection, and each of the bond pads can accommodate at least two wire bonds, and the two magnetic sensor chips are electrically interconnected via wire bonds to provide series-connected magnetoresistive elements to form a push-pull half-bridge circuit, the push-pull half-bridge circuitry including a half-bridge Vbias terminal, a half-bridge output terminal (Vbridge) and a half-bridge ground terminal;
an Application-Specific Integrated Circuit (ASIC) within the case and attached to the chip paddle, the ASIC including:
a VOUT bond pad;
a VCC bond pad;
a GND bond pad; and
bond pads for connecting to the push-pull half bridge circuit including a half bridge Vbias bond pad, a half bridge GND bond pad, and a half-bridge output (Vbridge) bond pad; and

a plurality of wire bonds, including:
a wire bond electrically connecting the VOUT bond pad of the ASIC to the output terminal;
a wire bond electrically connecting the VCC bond pad to the VCC terminal;
a wire bond electrically connecting the GND bond pad to the ground terminal;
a wire bond electrically connecting the half-bridge Vbias bond pad to the half-bridge Vbias terminal;
a wire bond electrically connecting the half-bridge GND bond pad to the half-bridge ground terminal; and
a wire bond electrically connecting the half-bridge output (Vbridge) to the half-bridge output terminal (Vbridge).

2. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the ASIC is configured to convert a signal at the half-bridge output terminal into a switching signal.

3. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the magnetoresistive elements include magnetic tunnel junction (MTJ) elements.

4. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the magnetoresistive elements include a giant magnetoresistive (GMR) elements.

5. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the magnetoresistive elements include an anisotropic magnetoresistive (AMR) elements.

6. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the magnetoresistive elements use on-chip permanent magnet bias.

7. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the magnetoresistive elements use in-stack magnet bias.

8. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the magnetoresistive elements use shape anisotropy for magnet bias.

9. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the two magnetic sensor chips are arranged such that their sensing axes are the same, and the sensing axis direction is parallel to the line through the center of both magnetic sensor chips.

10. The push-pull half-bridge magnetoresistive switch sensor according to claim 1 , wherein the two magnetic sensor chips are arranged such that their sensing axes are the same, and the sensing axis direction is perpendicular to the line through the center of both magnetic sensor chips.

11. A push-pull half-bridge magnetoresistive switch sensor, comprising:
a case;
a leadframe-based chip paddle with a protrusion to form a ground terminal extending from inside to outside of the case, a first pin to form a VCC terminal extending from inside to outside of the case, and a second pin to form an output terminal extending from inside to outside of the case;
two magnetic sensor chips within the case, including a first magnetoresistive sensor chip with at least one magnetoresistive element and a first pinned layer magnetization vector and a second magnetoresistive sensor chip with at least one magnetoresistive element and a second pinned layer magnetization vector, the first and second magnetoresistive sensor chips being attached to the chip paddle and arranged for the first and second pinned layer magnetization vectors to be at a 180 degree rotational angle relative to each other, wherein each of the magnetic sensor chips has corners and bond pads located in the corners for electrical connection, and the magnetic sensor chips are electrically connected via wire bonds to provide series-connected magnetoresistive elements to form a push-pull half-bridge circuit, the push-pull half-bridge circuitry including a half-bridge Vbias terminal, a half-bridge output terminal (Vbridge) and a half-bridge ground terminal;
an Application-Specific Integrated Circuit (ASIC) within the case and attached to the chip paddle, the ASIC including:
a VOUT bond pad;
a VCC bond pad;
a GND bond pad; and
bond pads for connecting to the push-pull half bridge circuit including a half bridge Vbias bond pad, a half bridge GND bond pad, and a half-bridge output (Vbridge) bond pad; and

a plurality of wire bonds, including:
a wire bond electrically connecting the VOUT bond pad of the ASIC to the output terminal;
a wire bond electrically connecting the VCC bond pad to the VCC terminal;
a wire bond electrically connecting the GND bond pad to the ground terminal;
a wire bond electrically connecting the half-bridge Vbias bond pad to the half-bridge Vbias terminal;
a wire bond electrically connecting the half-bridge GND bond pad to the half-bridge ground terminal; and
a wire bond electrically connecting the half-bridge output (Vbridge) to the half-bridge output terminal (Vbridge).

12. The push-pull half-bridge magnetoresistive switch sensor according to claim 5 , wherein the ASIC is configured to convert a signal at the half-bridge output terminal into a switching signal.

13. The push-pull half-bridge magnetoresistive switch sensor according to claim 11 , wherein the magnetoresistive elements include magnetic tunnel junction (MTJ) elements.

14. The push-pull half-bridge magnetoresistive switch sensor according to claim 11 , wherein the magnetoresistive elements include giant magnetoresistive (GMR) elements.

15. The push-pull half-bridge magnetoresistive switch sensor according to claim 11 , wherein the magnetoresistive elements include an anisotropic magnetoresistive (AMR) elements.

16. The push-pull half-bridge magnetoresistive switch sensor according to claim 11 , wherein the magnetoresistive elements use on-chip permanent magnet bias.

17. The push-pull half-bridge magnetoresistive switch sensor according to claim 11 , wherein the magnetoresistive elements use in-stack magnet bias.

18. The push-pull half-bridge magnetoresistive switch sensor according to claim 11 , wherein the magnetoresis

Assignees

• Multidimension Technology Co Ltd

Inventors

• Bai Jianmin
• Shen Weifeng
• Lei Xiaofeng
• Zhang Xiaojun
• Zhong Xiaojun

Classifications

• H03K17/9517

  using galvanomagnetic devices · CPC title

• G01R33/098 Primary

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

• G01R33/093

  using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00) · CPC title

• H03K17/97 Primary

  using a magnetic movable element · CPC title