阅读说明：本技术 一种电流检测功率器件、锂电池保护器及电子设备 (Current detection power device, lithium battery protector and electronic equipment ) 是由 张子敏 宋利军 王宇澄 于 2020-12-01 设计创作，主要内容包括：本发明提供一种用于锂电保护的电流检测功率器件,该器件电性连接锂电池保护板、锂电池保护器及电子设备,该器件由多个结构相同的功率器件并联集成而成；该器件至少包括一颗主功率器件和至少一颗电流检测器件,其中,主功率器件和电流检测器件共用漏极作为输入端,且共用栅极作为控制端；主功率器件和电流检测器件各自有独立的源极作为输出端。本发明提供的用于锂电保护的电流检测功率器件密度高、面积小,用在锂电保护电路中能够解决取样电阻的电阻值影响回路中的总电阻值,而导致整机待机时间下降的问题。(The invention provides a current detection power device for lithium battery protection, which is electrically connected with a lithium battery protection board, a lithium battery protector and electronic equipment, and is formed by integrating a plurality of power devices with the same structure in parallel; the device at least comprises a main power device and at least one current detection device, wherein the main power device and the current detection device share a drain electrode as an input end and a grid electrode as a control end; the main power device and the current detection device respectively have independent source electrodes as output ends. The current detection power device for lithium battery protection provided by the invention has high density and small area, and can solve the problem that the whole machine standby time is reduced because the resistance value of the sampling resistor influences the total resistance value in a loop when being used in a lithium battery protection circuit.)

1. A current detection power device for lithium battery protection is characterized in that the device is formed by integrating a plurality of power devices with the same structure in parallel; the current detection power device for lithium battery protection at least comprises a main power device and at least one current detection device, wherein the main power device and the current detection device share a drain electrode as an input end and a grid electrode as a control end; the main power device and the current detection device respectively have independent source electrodes as output ends.

2. The current detection power device for lithium ion protection according to claim 1, wherein the plurality of power devices having the same structure are all surface electrode pull-down structures.

3. The current sensing power device for lithium electrical protection according to claim 2, wherein the surface electrode pull-down structure is a Body pull-down structure.

4. The current sensing power device for lithium electrical protection according to claim 3, wherein the power device of Body pull-down structure comprises:

a P-type substrate;

the grid electrode is respectively positioned on the source electrode and the drain electrode at two sides of the grid electrode;

a Body region located at the bottom of the P-type substrate;

wherein the gate, the source and the drain are drawn from a surface of the device; the Body region leads from the bottom of the device.

5. The current sensing power device for lithium electrical protection according to claim 2, wherein the surface electrode pull-down structure is a drain pull-down structure.

6. The current sensing power device for lithium electrical protection according to claim 5, wherein the power device of the drain pull-down structure comprises:

a BN region;

an N-type well region located above the BN region;

and the deep hole region is positioned in the N-type well region, is connected with the BN region, and is filled with metal to lead out a drain electrode, so that the N + region of the drain electrode is conducted with the BN region.

7. The current sensing power device for lithium electrical protection according to claim 1, wherein the plurality of structurally identical power devices are all gate Trench (Trench) structures.

8. The current sensing power device for lithium electrical protection according to claim 7, wherein the power device of gate Trench structure comprises:

a BN region;

an N-type well region located above the BN region;

the drain electrode is positioned in the middle of the N-type well region;

the first grid region and the second grid region are located on two sides of the drain electrode and are arranged opposite to the drain electrode, and the first grid region and the second grid region are both of Trench structures.

9. The current detection power device for lithium ion battery protection according to claim 7, wherein the device current flows from an active region N + region of the source electrode, then bypasses a gate of a two-side Trench structure, and is finally collected by an N-type source region N + of a drain region.

10. The current detection power device for lithium battery protection according to claim 9, wherein a source terminal of the current detection device is connected to a current detection VM terminal of a lithium battery protection board; when the main power device is conducted, the VM end carries out current detection through direct sampling of a source end of the current detection device.

11. A lithium battery protector, characterized in that it comprises a current sensing power device for lithium battery protection according to any one of claims 1 to 10.

12. An electronic device characterized in that the electronic device comprises the lithium battery protector according to claim 11.

Technical Field

The invention relates to the field of lithium battery protection, in particular to a current detection power device for lithium battery protection, a lithium battery protector and electronic equipment.

Background

A lithium battery charging protection circuit in the prior art, as shown in fig. 1, includes a lithium battery protection board, a resistor R2, a MOS transistor Q1, and a MOS transistor Q2. In fig. 1, the discharge control end DO of the lithium battery protection board is connected to the gate of the MOS transistor Q1, the source of the MOS transistor Q1 is connected to the negative electrode of the lithium battery, and the drain of the MOS transistor Q1 is connected to the drain of the MOS transistor Q2; the charging control end CO of the lithium battery protection board is connected with the grid electrode of the MOS tube Q2, and the source electrode of the MOS tube Q2 is connected with one end of a resistor R2 and the negative output VCC-of the charging circuit; the other end of the resistor R2 is connected with the first detection end VM of the lithium battery protection board.

In the prior art, the first detection end VM of the lithium battery protection board generally detects the charging current through the resistor R2, but the resistor R2 must adopt a high-precision resistor, the cost is high, and the current detection precision is limited by the precision of R2; and the response speed of such a circuit structure is not fast. And for a large-capacity battery, the resistance value of the sampling resistor can greatly increase the total resistance value in the whole loop, so that the power consumption of the system is increased, and the standby time of the whole machine is greatly reduced.

Disclosure of Invention

The invention provides a device for lithium battery protection, which solves the problem that the standby time of the whole machine is reduced because the resistance value of a sampling resistor influences the total resistance value in a loop in the prior art.

In order to solve the technical problems, the invention adopts a technical scheme that a current detection power device for lithium battery protection is provided, and is characterized in that the device is formed by integrating a plurality of power devices with the same structure in parallel; the current detection power device for lithium battery protection comprises

The current detection device comprises at least one main power device and at least one current detection device, wherein the main power device and the current detection device share a drain electrode as an input end and a grid electrode as a control end; the main power device and the current detection device respectively have independent source electrodes as output ends.

Furthermore, the power devices with the same structure are all surface electrode pull-down structures.

Further, the surface electrode pull-down structure is a Body pull-down structure.

Further, the power device of the Body pull-down structure comprises:

a P-type substrate;

the grid electrode is respectively positioned on the source electrode and the drain electrode at two sides of the grid electrode;

a Body region located at the bottom of the P-type substrate;

wherein the gate, the source and the drain are drawn from a surface of the device; the Body region leads from the bottom of the device.

Further, the surface electrode pull-down structure is a drain pull-down structure.

Further, the power device of the drain pull-down structure comprises:

a BN region;

an N-type well region located above the BN region;

and the deep hole region is positioned in the N-type well region, is connected with the BN region, and is filled with metal to lead out a drain electrode, so that the N + region of the drain electrode is conducted with the BN region.

Further, the plurality of power devices with the same structure are all of a grid groove (Trench) structure.

Further, the power device with the gate Trench structure comprises:

a BN region;

an N-type well region located above the BN region;

the drain electrode is positioned in the middle of the N-type well region;

the first grid region and the second grid region are located on two sides of the drain electrode and are arranged opposite to the drain electrode, and the first grid region and the second grid region are both of Trench structures.

Further, the device current flows in from the active region N + region of the source electrode, then bypasses the grids of the Trench structures on two sides, and is finally collected by the N-type source region N + of the drain region.

Furthermore, a source terminal of the current detection device is connected with a current detection VM terminal of the lithium battery protection board; when the main power device is conducted, the VM end carries out current detection through direct sampling of a source end of the current detection device.

In order to solve the technical problem, another technical solution adopted by the present invention is to provide a lithium battery protector, where the lithium battery protector includes the current detection power device for lithium battery protection.

In order to solve the technical problem, another technical solution adopted by the present invention is to provide an electronic device, where the electronic device includes the lithium battery protector.

The invention has the beneficial effects that: the invention provides a current detection power device for lithium battery protection, which integrates a plurality of MOS power devices into one power device, and the power device is used in a lithium battery protection circuit, so that a high-precision resistor is not used in the circuit, the maximum current precision requirement can be met, the cost is reduced, the current detection precision is improved, and the advantage of high reaction speed is achieved.

Drawings

FIG. 1 is a schematic diagram of a conventional lithium battery charging protection circuit;

FIG. 2 is a schematic diagram of a lithium battery charging protection circuit according to the present invention;

fig. 3 is a schematic structural diagram of a single device in the current detection power device for lithium electric protection in the invention;

fig. 4 is a schematic structural diagram of a current detection power device for lithium electric protection in the present invention;

fig. 5 is another schematic diagram of a single device in the current sensing power device for lithium battery protection according to the present invention;

fig. 6 is another schematic diagram of the current detection power device for lithium battery protection according to the present invention;

fig. 7 is another schematic diagram of a single device in the current sensing power device for lithium battery protection according to the present invention;

fig. 8 is another schematic diagram of the current detection power device for lithium battery protection according to the present invention.

Detailed Description

In order to facilitate an understanding of the invention, the invention is described in more detail below with reference to the accompanying drawings and specific examples. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It is to be noted that, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 2, in the present embodiment, the current detection power device for lithium battery protection is electrically connected to the lithium battery protection board, and the power device is formed by integrating a plurality of power devices with the same structure in parallel; in this embodiment, the current detection power device for lithium battery protection is formed by connecting and integrating a main power device FET1 and a current detection device FET2 in parallel, wherein the drains of the main power device FET1 and the current detection device FET2 are connected, the drains of the main power device FET1 and the current detection device FET2 share the drains as input terminals, and the gates of the main power device FET1 and the current detection device FET2 share the gates as control terminals, wherein the gate of the main power device FET1 is connected to the DO terminal of the lithium battery protection board, and the gate of the current detection device FET2 is connected to the; the main power device FET1 and the current detection device FET2 each have an independent source as an output terminal, wherein the source S1 of the main power device FET1 is connected to the negative electrode of the battery, the source CS of the current detection device FET2 is connected to the current detection VM terminal of the lithium battery protection board, and when the main power device FET1 is turned on, the VM terminal performs current detection by directly sampling the source CS terminal of the current detection device FET 2.

The current detection power device for lithium battery protection in the embodiment is formed by integrating a plurality of power devices with the same structure in parallel, wherein each power device with the same structure is a surface electrode pull-down structure and comprises a Body pull-down structure and a drain pull-down structure.

As shown in fig. 3 and 4, fig. 3 is a schematic structural diagram of a single device in a current detection power device for lithium electric protection; fig. 4 is a schematic diagram of a current sensing power device for lithium battery protection.

In fig. 3, a single device includes a P-type substrate, a gate, a source and a drain led out from the surface of the device, wherein the source and the drain are located at two sides of the gate; the Body region is located at the bottom of the P-type substrate, and the Body region is led out from the bottom of the device. And the Body region is led out from the bottom of the device, and the source electrode and the drain electrode are led out from the surface of the device, so that the reliability of the device is improved on one hand, and the area of the device is reduced on the other hand.

Further, the device in this embodiment includes a first N-type well region 101 and a second N-type well region 102, where the first N-type well region is provided with a first N + contact region 103, and the second N-type well region is provided with a second N + contact region 104; wherein the drain leads from a first N + contact region 103 and the source leads from a second N + contact region 104.

The device further includes a first STI region 105 and a second STI region 106, where the first STI region 105 is located on the other side of the first N-type well region 101 and the second STI region 106 is located on the other side of the second N-type well region 102.

The current flow path in the device is: current flows in from the Drain terminal of each device, down through the Body region, and up out from the Source terminal.

In the device in the embodiment, the Body region is led out from the surface of the device instead of being led out from the bottom of the device, the Body region is flush with the two side edges of the P-type substrate of the device, and the source electrode and the drain electrode are led out from the surface of the device, so that the reliability of the device is improved, the area of the device is reduced, and a condition is provided for integration of a plurality of devices.

Referring to fig. 4, a plurality of devices are integrated on the same chip, and each device is composed of a gate in the middle, and a drain and a source on both sides of the gate; when a plurality of devices are connected in parallel, if the drains of the two devices are adjacent, the drains of the two devices are combined into one drain; and if the sources of the two devices are adjacent, the sources of the two devices are merged into one source.

In the device for lithium battery protection in the embodiment, the plurality of devices are integrated on the same chip, and the Body of the plurality of devices is pulled down and is connected out from the bottom of the device, so that the area of the device is reduced; when a plurality of devices are connected in parallel, the homopolarity of the adjacent devices is combined, the area of the devices is further reduced, and the requirement of continuously improved density is met.

As shown in fig. 5 and 6, fig. 5 is another schematic structural diagram of a single device in the current detection power device for lithium electric protection; fig. 6 is another schematic diagram of a current sensing power device for lithium battery protection.

As shown in fig. 5, a single device includes a BN region, and a final N-type well region is formed by injecting and diffusing an N-type well region through a thermal process, where the N-type well region is located above the BN region; the device further comprises a Drain region arranged on the N-type well region, a deep hole region is opened in the Drain region and connected with the BN region, and metal is filled in the deep hole region to be led out, so that current flows into the BN end directly after flowing out of the N + PB, and then is led out through the Drain hole of the BN end.

The device in this embodiment includes a first P-type well region 201 and a second P-type well region 202, where the first P-type well region 201 and the second P-type well region 201 are respectively located at two sides of the deep hole region. The first P-type well region 201 comprises a first N-type source region 203 and a first P + -type contact region 204, wherein the first N-type source region 203 and the first P + -type contact region 204 are arranged side by side; the second P well region 202 includes a second N source region 205 and a second P + contact region 206, wherein the second N source region 205 and the second P + contact region 206 are arranged side by side.

The device further comprises a first source 207, the first source 207 leading from the first N-type source region 203 and the first P + -type contact region 204; and a second source electrode 208, the second source electrode 208 being led out from the second N-type source region 205 and the second P + -type contact region 206. A first gate 209, the first gate 209 being located between the first source 207 and the drain; a second gate 210, the second gate 210 being located between the second source 208 and the drain.

In the device in this embodiment, a deep hole region is opened in the Drain region of the device, and the deep hole region is filled with metal to be led out, so that the current flows out of N + PB and then directly flows into the BN terminal, and then is led out through the Drain hole of the BN terminal, thereby reducing the area of the device, but for the BN region led out by the Drain, the area of the led out current is enlarged instead, and the on-resistance is reduced.

Referring to fig. 6, a plurality of devices are integrated on the same chip, adjacent devices merge adjacent sources and share the same source, and a PB region of the shared source is provided with a P + and an N + on each side of the P + to lead out respective sources. Therefore, a plurality of devices are integrated in parallel on the same chip, and the area of the devices is greatly reduced.

In the device for lithium battery protection in this embodiment, the plurality of devices are integrated on the same chip, and the drains of the plurality of devices are pulled down, so that the current flows out of N + PB and then directly flows into the BN terminal, and is then led out through the Drain hole of the BN terminal, thereby reducing the area of the device, but for the BN region led out by the Drain, the area led out by the current is enlarged, and the on-resistance is reduced.

The plurality of devices with the same structure, which form the current detection power device for lithium battery protection in the embodiment, may also be devices with a gate Trench structure. Fig. 7 is another schematic structural view of a single device in a current detection power device for lithium electric protection, as shown in fig. 7 and 8; fig. 8 is another schematic diagram of a current sensing power device for lithium battery protection.

As shown in fig. 7, a single device includes a BN region, and a final N-type well region is formed by injecting and diffusing an N-type well region through a thermal process, where the N-type well region is located above the BN region; the device further comprises a drain region arranged in the middle of the N-type well region, wherein the drain region comprises an N + contact region and a drain electrode led out from the N + contact region. And a first grid region 30 and a second grid region 40 are respectively arranged at two sides of the drain N + contact region, and the first grid region 30 and the second grid region 40 are both of Trench structures.

The device in this embodiment includes a first P-type well region 101 and a second P-type well region 201, where the first P-type well region 101 is located on the other side of the first gate region 307, and the second P-type well region 302 is located on the other side of the second gate region 308. In the first P-type well region 301, a first N-type Source region 304 and a first P + -type contact region 303 are provided, and a first Source1 is drawn out at the first N-type Source region 304 and the first P + -type contact region 303; in the second P-type well region 302, a second N-type Source region 306 and a second P + type contact region 305 are disposed, and a second Source2 is led out from the second N-type Source region 306 and the second P + contact region 305.

The current of the device in this embodiment flows out from the first N-type source region 304 and the second N-type source region 306 of the first P-type well region 301 and the second P-type well region 302, respectively, then bypasses the gates of the Trench structures on both sides, and is finally collected by the N-type source region N + of the drain region.

In the device in the embodiment, the gate of the device is changed into the Trench structure, so that the voltage-resistant region and the current region of the whole device are turned to the vertical direction from the horizontal direction, the whole area of the device is greatly reduced, and the on-resistance of the device is also improved.

Referring to fig. 8, a plurality of devices are assembled in parallel on the same chip, and the original package of each device is composed of a middle Drain and sources on two sides of the Drain; when a plurality of devices are arranged side by side, each device and an adjacent device share the P + of a Source end, and the shared Source end comprises a middle P + and two sides of N +; the edgemost Source terminal contains one P + and one N +.

The current of the device in this embodiment respectively flows out from the N-type Source region N + of the P-type well region at the Source end on both sides of the Drain end, then bypasses the gates of the Trench structures on both sides, and is finally collected by the N-type Source region N + of the Drain region Drain.

In the device for lithium battery protection in this embodiment, the plurality of devices are integrated on the same chip, and the gate regions of the plurality of devices are set to the Trench structure, so that the whole withstand voltage region and the whole current region of the device are turned to the vertical direction from the horizontal direction, the whole area of the device is greatly reduced, and the on-resistance of the device is also improved.

According to the current detection power device for lithium battery protection in the embodiment of the invention, a plurality of MOS power devices are integrated in one power device, so that the area of the device is greatly reduced; in addition, the power device is used in the lithium battery protection circuit, a high-precision resistor is not used in the circuit, the requirement of maximum current precision can be met, the cost is reduced, the current detection precision is improved, and the power device has the advantage of high reaction speed.

The embodiment of the invention also provides a lithium battery protector, and the lithium battery protector in the embodiment comprises the current detection power device for lithium battery protection in the embodiment.

The embodiment of the invention also provides electronic equipment, and the electronic equipment in the embodiment comprises the lithium battery protector in the embodiment. The electronic device in this embodiment may be any device that includes the lithium battery protector in the foregoing embodiments.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.