阅读说明：本技术 一种过流保护电路、方法及电子设备 (Overcurrent protection circuit and method and electronic equipment ) 是由 不公告发明人 于 2021-10-20 设计创作，主要内容包括：本申请涉及一种过流保护电路,包括电流镜像模块、开关控制模块、高低压隔离模块、偏置电流输出模块、第二电流镜、基准电流输出模块：所述开关控制模块与所述电流镜像模块以及所述高低压隔离模块连接,所述高低压隔离模块与偏置电流输出模块以及所述第二电流镜的一端连接,所述第二电流镜的另一端与所述基准电流输出模块共同连接到比较电流输出端上。本申请的设计实现了高压下HSD驱动功率管的电压、电流检测和保护；包括对大功率管电流的采样和处理,高低电压转换和低压比较输出的控制电路。(The application relates to an overcurrent protection circuit, including current mirror module, on-off control module, high-low voltage isolation module, bias current output module, second current mirror, reference current output module: the switch control module is connected with the current mirror module and the high-low voltage isolation module, the high-low voltage isolation module is connected with the bias current output module and one end of the second current mirror, and the other end of the second current mirror and the reference current output module are connected to the comparison current output end together. The design of the application realizes the voltage and current detection and protection of the HSD driving power tube under high voltage; the control circuit comprises a sampling and processing circuit for the current of the high-power tube, a high-low voltage conversion circuit and a low-voltage comparison output circuit.)

1. The utility model provides an overcurrent protection circuit which characterized in that, includes current mirror module, on-off control module, high-low voltage isolation module, bias current output module, second current mirror, reference current output module:

the switch control module is connected with the current mirror module and the high-low voltage isolation module, the high-low voltage isolation module is connected with the bias current output module and one end of the second current mirror, and the other end of the second current mirror and the reference current output module are connected to the comparison current output end together.

2. The circuit of claim 1, wherein the current mirror module comprises:

a first current mirror;

a high-power output tube consisting of a fourth PMOS tube and a detection current sampling tube consisting of a fifth PMOS tube;

sampling a resistor; two ends of the sampling resistor are respectively connected with the first current mirror and the drain electrode of the detection current sampling tube;

the source electrode of the high-power output tube is connected with the source electrode of the detection current sampling tube;

and the grid of the high-power output tube is connected with the grid of the detection current sampling tube and is connected with a switching signal.

3. The circuit of claim 2, wherein the first current mirror is comprised of a first PMOS transistor and a second PMOS transistor;

the grid electrode of the first PMOS tube is connected with the grid electrode of the second PMOS tube, and the grid electrode of the first PMOS tube is also connected with the drain electrode of the first PMOS tube.

4. The circuit of claim 2, wherein the bias current output module comprises: a plurality of NMOS transistors biased with a first constant bias voltage;

the grid electrodes of the NMOS tubes biased by the first constant bias voltage are connected, and the drain electrodes of the NMOS tubes biased by the first constant bias voltage are connected in common.

5. The circuit of claim 4, wherein the high-low voltage isolation module comprises: an enable signal input end and a plurality of high-low voltage isolation tubes;

the grid electrodes of the high-voltage and low-voltage isolation tubes are connected and respectively connected to the input end of the enable signal;

the plurality of high and low pressure separator tubes comprises: a third NMOS transistor, a fourth NMOS transistor, and a fifth NMOS transistor.

6. The circuit of claim 5,

the switch control module includes: a comparison path switching-off control tube consisting of a third PMOS tube;

the drain electrode of the detection current sampling tube is connected with the source electrode of the comparison access disconnection control tube;

the reference current output module includes: a sixth PMOS tube biased by a second constant bias voltage;

the drain electrode of the sixth PMOS tube is connected with the second current mirror;

and the drain electrode of the sixth PMOS tube is also connected with the output end of the overcurrent protection circuit.

7. The circuit according to any one of claims 1-6, wherein the second current mirror is composed of a first NMOS transistor and a second NMOS transistor;

the grid electrode of the first NMOS tube is connected with the grid electrode of the second NMOS tube, and the grid electrode of the first NMOS tube is also connected with the source electrode of the first NMOS tube.

8. The circuit of claim 7,

the drain electrode of the first PMOS tube is connected with the source electrode of the third NMOS tube;

the source electrode of the second PMOS tube is connected with the grid electrode of the comparison access on-off control tube, and the drain electrode of the second PMOS tube is also connected with the source electrode of the fourth NMOS tube;

the plurality of NMOS tubes biased with a first constant bias voltage comprises:

a sixth NMOS transistor and the seventh NMOS transistor;

a reference voltage is added to the drain electrode of the sixth PMOS tube biased by the second constant bias voltage;

the drain electrode of the third NMOS tube is connected with the source electrode of the sixth NMOS tube;

and the drain electrode of the fourth NMOS tube is connected with the source electrode of the seventh NMOS tube.

9. The circuit of claim 7, wherein the sampling resistor is a digitally adjustable resistor.

10. An electronic device equipped with the overcurrent protection circuit according to any one of claims 1 to 9.

11. An overcurrent protection method applied to the overcurrent protection circuit according to any one of claims 1 to 9, comprising:

collecting the current intensity output by the high-power output tube based on the current mirror module, and carrying out current mirror copy and working state judgment on the current intensity, wherein the working state judgment comprises the judgment of whether the collected current exceeds a preset threshold value;

when the current flowing through the current mirror module does not exceed a preset threshold value, the switch control module is closed, the current branch of the switch control module cannot flow to a subsequent circuit through the switch control module, the second current mirror cannot be opened and presents a high-resistance state, the current input to the comparison output end by the second current mirror and the reference current output module is shared, and the result after comparison and judgment is a high level;

when the current flowing through the current mirror module exceeds the preset threshold value, the comparison switch control module is opened, the current branch of the comparison switch control module flows into the second current mirror through the switch control module, the second current mirror is opened at the moment, current mirror image copying is carried out on the current branch, the current which is output to the comparison output end through the reference output module and the second current mirror together at the moment is carried out, and the result after comparison and judgment is low level.

Technical Field

The present disclosure relates to the field of power management chip technologies, and more particularly, to an overcurrent protection circuit, method and electronic device.

Background

In industrial production, any device with a determined width has a specific safe operating voltage and safe operating current range according to the safe operating characteristics of circuit components. Under a high-voltage working environment, if the HSD power tube needs to realize normal work, the HSD power tube is required to have certain capacity of flowing large current, and meanwhile, the voltage and the current are also required to be in a safe working range.

In order to achieve the purpose, in the working process of the circuit, the current flowing through the HSD power tube needs to be synchronously detected, and when the current exceeds the safe working range of the component, the high-voltage power tube can be switched off so as to protect the switching tube from being damaged. However, the prior art lacks an effective technical means for detecting the current of the HSD driving power tube at high voltage.

Disclosure of Invention

For solving prior art and can't solve the technical problem to the current detection and the protection of HSD drive power tube under high pressure, this application provides an overcurrent protection circuit, including current mirror module, on-off control module, high-low voltage isolation module, bias current output module, second current mirror, reference current output module:

the switch control module is connected with the current mirror module and the high-low voltage isolation module, the high-low voltage isolation module is connected with the bias current output module and one end of the second current mirror, and the other end of the second current mirror and the reference current output module are connected to the comparison current output end together.

Further, the current mirror module includes:

a first current mirror;

a high-power output tube consisting of a fourth PMOS tube and a detection current sampling tube consisting of a fifth PMOS tube;

sampling a resistor; two ends of the sampling resistor are respectively connected with the first current mirror and the drain electrode of the detection current sampling tube;

the source electrode of the high-power output tube is connected with the source electrode of the detection current sampling tube;

and the grid of the high-power output tube is connected with the grid of the detection current sampling tube and is connected with a switching signal.

Further, the first current mirror is composed of a first PMOS tube and a second PMOS tube;

the grid electrode of the first PMOS tube is connected with the grid electrode of the second PMOS tube, and the grid electrode of the first PMOS tube is also connected with the drain electrode of the first PMOS tube.

Further, the bias current output module includes: a plurality of NMOS transistors biased with a first constant bias voltage;

the grid electrodes of the NMOS tubes biased by the first constant bias voltage are connected, and the drain electrodes of the NMOS tubes biased by the first constant bias voltage are connected in common.

Further, the high-low voltage isolation module comprises: an enable signal input end and a plurality of high-low voltage isolation tubes;

the grid electrodes of the high-voltage and low-voltage isolation tubes are connected and respectively connected to the input end of the enable signal;

the plurality of high and low pressure separator tubes comprises: a third NMOS transistor, a fourth NMOS transistor, and a fifth NMOS transistor.

Further, in the present invention,

the switch control module includes: a comparison path switching-off control tube consisting of a third PMOS tube;

the drain electrode of the detection current sampling tube is connected with the source electrode of the comparison access disconnection control tube;

the reference current output module includes: a sixth PMOS tube biased by a second constant bias voltage;

the drain electrode of the sixth PMOS tube is connected with the second current mirror;

and the drain electrode of the sixth PMOS tube is also connected with the output end of the overcurrent protection circuit.

Further, the second current mirror is composed of a first NMOS tube and a second NMOS tube;

the grid electrode of the first NMOS tube is connected with the grid electrode of the second NMOS tube, and the grid electrode of the first NMOS tube is also connected with the source electrode of the first NMOS tube.

Further, it is characterized in that the first and second light-emitting diodes are arranged in a matrix,

the drain electrode of the first PMOS tube is connected with the source electrode of the third NMOS tube;

the source electrode of the second PMOS tube is connected with the grid electrode of the comparison access on-off control tube, and the drain electrode of the second PMOS tube is also connected with the source electrode of the fourth NMOS tube;

the plurality of NMOS tubes biased with a first constant bias voltage comprises:

a sixth NMOS transistor and the seventh NMOS transistor;

a reference voltage is added to the drain electrode of the sixth PMOS tube biased by the second constant bias voltage;

the drain electrode of the third NMOS tube is connected with the source electrode of the sixth NMOS tube;

and the drain electrode of the fourth NMOS tube is connected with the source electrode of the seventh NMOS tube.

Further, the sampling resistor is a digital adjustable resistor.

In order to achieve the above technical object, the present application can also provide an electronic device, where the electronic device carries the above overcurrent protection circuit.

In order to achieve the above technical object, the present application can also provide an overcurrent protection method applied to the above overcurrent protection circuit, including:

collecting the current intensity output by the high-power output tube based on the current mirror module, and carrying out current mirror copy and working state judgment on the current intensity, wherein the working state judgment comprises the judgment of whether the collected current exceeds a preset threshold value;

when the current flowing through the current mirror module does not exceed a preset threshold value, the switch control module is closed, the current branch of the switch control module cannot flow to a subsequent circuit through the switch control module, the second current mirror cannot be opened and presents a high-resistance state, the current input to the comparison output end by the second current mirror and the reference current output module is shared, and the result after comparison and judgment is a high level;

when the current flowing through the current mirror module exceeds the preset threshold value, the comparison switch control module is opened, the current branch of the comparison switch control module can flow into the second current mirror through the switch control module, the second current mirror is opened at the moment, current mirror image copying is carried out on the current branch, the current which is output to the comparison output end through the reference output module and the second current mirror together at the moment is carried out, and the result after comparison and judgment is low level.

The beneficial effect of this application does:

the application designs a circuit structure and detects the electric current that flows through HSD power tube, through the sampling to HSD power tube electric current, with the current mirror image of corresponding proportion to the conversion through the level is handled the electric current conversion of high-pressure workspace to the low pressure part, reduces the design degree of difficulty of circuit, provides the detection control signal of a low pressure for back level circuit, realizes the control operation of digital control module to the circuit.

The design of the application realizes the voltage and current detection and protection of the HSD driving power tube under high voltage; the control circuit comprises a sampling and processing circuit for the current of the high-power tube, a high-low voltage conversion circuit and a low-voltage comparison output circuit.

Drawings

Fig. 1 shows a schematic structural diagram of a circuit according to a first embodiment of the present application;

fig. 2 shows a schematic diagram of a preferred implementation of the circuit of the first embodiment of the present application.

Detailed Description

Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It is to be understood that such description is merely illustrative and not intended to limit the scope of the present application. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present application.

Various structural schematics according to embodiments of the present application are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers, and relative sizes and positional relationships therebetween shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, as actually required.

The first embodiment is as follows:

as shown in fig. 1:

the application provides an overcurrent protection circuit, include:

the current mirror module 101, the switch control module 102, the high-low voltage isolation module 103, the bias current output module 105, the second current mirror 106, and the reference current output module 104:

the switch control module 102 is connected to the current mirror module 101 and the high-low voltage isolation module 103, the high-low voltage isolation module 103 is connected to the bias current output module 105 and one end of the second current mirror 106, and the other end of the second current mirror 106 and the reference current output module 104 are connected to the comparison current output end.

As shown in fig. 2:

as preferred embodiments of the present application:

an overcurrent protection circuit comprising:

the current mirror module 101, the current mirror module 101 is connected with the switch signal SW; the current mirror module 101 specifically includes:

a high-power output tube consisting of a fourth PMOS tube M12 and a detection current sampling tube consisting of a fifth PMOS tube M13;

the high-power output tube is connected with the source electrode of the detection current sampling tube; the drain electrode of the detection current sampling tube is connected with the source electrode of the comparison access cut-off control tube; the high-power output tube is connected with the grid electrode of the detection current sampling tube and is connected with the switch signal SW.

A first current mirror and a second current mirror; the first current mirror is composed of a first PMOS tube M1 and a second PMOS tube M2; the grid electrode of the first PMOS transistor M1 is connected with the grid electrode of the second PMOS transistor M2, and is connected with the drain electrode of the first PMOS transistor M1. The second current mirror is composed of a first NMOS transistor M6 and a second NMOS transistor M7; the grid electrode of the first NMOS transistor M6 is connected with the grid electrode of the second NMOS transistor M7, and the grid electrode of the first NMOS transistor M6 is also connected with the source electrode of the first NMOS transistor M6.

A sampling resistor R1; two ends of the sampling resistor R1 are respectively connected with the first current mirror and the drain electrode of the detection current sampling tube; the sampling resistor R1 is a digitally adjustable resistor.

Comparing the path breaking control tube; the comparison channel breaking control tube consists of a third PMOS tube M5.

A high-low voltage isolation module 103 for isolating a high-voltage region and a low-voltage region of the circuit; the high-low pressure isolation module 103 is composed of a plurality of high-low pressure isolation pipes; the grid electrodes of the high-voltage and low-voltage isolation tubes are connected and are connected with an enable signal EN; the plurality of high and low pressure isolation tube bodies comprises: a third NMOS transistor M9, a fourth NMOS transistor M10, and a fifth NMOS transistor M11; the drain electrode of the comparison path cut-off control tube is connected with the drain electrode of the fifth NMOS tube M11; the source of the fifth NMOS transistor M11 is connected to the drain of the first NMOS transistor M6.

The drain electrode of the first PMOS pipe M1 is connected with the drain electrode of the third NMOS pipe M9;

the drain of the second PMOS transistor M2 is connected to the gate of the comparison-path-breaking control transistor, and the drain of the second PMOS transistor M2 is also connected to the drain of the fourth NMOS transistor M10.

The second current mirror is connected with the comparison access cut-off control tube through the high-low voltage isolation module;

the overcurrent protection circuit of this application still includes:

a bias current output module 105 composed of a plurality of NMOS transistors biased by a first constant bias voltage, and a sixth PMOS transistor M8 biased by a second constant bias voltage;

the grids of the NMOS tubes biased by the first constant bias voltage of the bias current output module 105 are connected;

the plurality of NMOS tubes biased with a first constant bias voltage includes:

a sixth NMOS transistor M3 and a seventh NMOS transistor M4;

the drain electrode of the sixth PMOS pipe M8 biased by the second constant bias voltage is added with the reference voltage VREF; the source electrode of the third NMOS tube M9 is connected with the drain electrode of the sixth NMOS tube M3;

the source electrode of the fourth NMOS tube M10 is connected with the drain electrode of the seventh NMOS tube M4;

the sources of the sixth NMOS transistor M3, the seventh NMOS transistor M4, the first NMOS transistor M6 and the second NMOS transistor M7 are connected to the ground.

The source electrodes of the NMOS tubes biased by the first constant bias voltage are grounded in common;

the drain electrode of the sixth PMOS tube M8 is connected with the second current mirror;

the drain of the sixth PMOS transistor M8 is also connected to the output terminal of the overcurrent protection circuit of the present application.

Example two:

the present application can also provide an electronic device, where the electronic device carries the overcurrent protection circuit described in the first embodiment.

Example three:

the present application can also provide an overcurrent protection method, applied to the overcurrent protection circuit in the first embodiment, including:

collecting and acquiring the current intensity output by a high-power output tube based on a current mirror module, and carrying out current mirror copy and working state judgment on the current intensity, wherein the working state judgment comprises the step of judging whether the collected current exceeds a preset threshold value;

when the current flowing through the current mirror module does not exceed the preset threshold value, the switch control module is closed, the current branch of the switch control module cannot flow to a subsequent circuit through the switch control module, the second current mirror cannot be opened and is in a high-resistance state, the current input to the comparison output end by the second current mirror and the reference current output module is shared at the moment, and the result after comparison and judgment is a high level;

when the current flowing through the current mirror module exceeds a preset threshold value, the comparison switch control module is opened, the current branch can flow into the second current mirror through the switch control module, the second current mirror is opened at the moment, current mirror image copying is carried out on the current branch, the current which is output to the comparison output end through the reference output module and the second current mirror is carried out together at the moment, and the result after comparison and judgment is a low level.

Specifically, the current sampling module collects the intensity of the current flowing through and judges the working state,

if the current flowing through the current sampling module is normal and not overcurrent, the voltage drop on the sampling resistor R1 is small, the first current mirror is normally opened, the grid voltage of the comparison path cut-off control tube is pulled high, so that the first current mirror cannot be opened, the current branch cannot flow to a subsequent circuit through the comparison path cut-off control tube, the second current mirror cannot be opened, a high-resistance state is presented, and the output OUT of the circuit is pulled to a high level by VREF through a sixth PMOS tube M8;

if the current flowing through the current sampling module is large, the voltage drop on the sampling resistor R1 is increased, the first current mirror cannot be normally opened, the comparison path on-off control tube is opened, the current flowing through the current sampling module does not pass through the sampling resistor R1 but flows to the second current mirror through the comparison path on-off control tube, and the current after passing through the second current mirror is compared with the reference current at the drain end of the sixth PMOS tube M8 to output a low level.

When the chip starts to work normally when the VBUS is powered, when the SW switch control signal is pulled low, the M12 and M13 PMOS transistors are turned on, and because this circuit is used in the charging path, the current flowing through the M12 transistor is large, which is in ampere level, so an overcurrent detection circuit needs to be added to avoid burning the chip due to the excessive current.

In the circuit, the drain current voltage of M3 and M4 is the same, M9 and M10 have the same bias generation, the drain current voltage is also the same, M1 and M2 are current mirrors, M1 is diode-connected and is in a saturation region, but whether the M2 is opened or not is influenced by the drain voltage, and the drain voltage is influenced by the M13 tube current. The specific effects and work are described as follows:

when the M12 tube is opened, a large current is generated on the M12 tube, the M12 tube and the M13 tube have a mirror image relationship, and the M13 tube current is about one thousandth of the M12 current.

When the current of the M12 tube and the M13 tube is normal and not overcurrent, the voltage drop of a resistor R1 is small, the VSG of the M2 tube is enough to normally open the M2 tube, the grid voltage of the M5 tube is pulled high, so that the M5 tube cannot be opened, a current branch cannot flow to a subsequent circuit through an M5 path, the M6 tube M7 tube cannot be opened, a high-resistance state is presented, the output OUT is pulled to a high level through the M8 tube by the VREF, and the high level of the output OUT represents that the current circuit is overcurrent;

however, when the currents of the M12 and M13 tubes are larger, the voltage drop on the R1 resistor is increased, which causes the source voltage of the M2 tube to be lower, the VSG of the M2 tube is lower, so that the M2 cannot be opened, the gate of the M5 tube is pulled down by GND through the conductive M10M 4 tube, the M5 tube is opened, the M13 current does not flow to the M5 through the R1, flows to the M11, is mirrored by the M6M 7, and then outputs a low level after being compared with the reference current at the drain terminal of the M8, and the low level of the output OUT indicates that the current circuit is not overcurrent.

The embodiments of the present application are described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present application. The scope of the application is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the present application, and such alternatives and modifications are intended to be within the scope of the present application.