CN114498596A

CN114498596A - Electrostatic protection circuit, electrostatic protection method and integrated circuit

Info

Publication number: CN114498596A
Application number: CN202210319731.7A
Authority: CN
Inventors: 柯毅; 刘坤
Original assignee: Wuhan Silicon Integrated Co Ltd
Current assignee: Wuhan Silicon Integrated Co Ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2022-05-13

Abstract

The application discloses electrostatic protection circuit, electrostatic protection method and integrated circuit, this electrostatic protection circuit includes: the trigger module is configured to respond to the electrostatic discharge signal of the target circuit and output a voltage control signal to the leakage protection module and the pull-down protection module; the leakage protection module is configured to respond to the voltage control signal and form an electrostatic leakage path so as to discharge an electrostatic discharge signal of the target circuit through the electrostatic leakage path; the pull-down protection module is configured to output a shutdown signal to the target circuit in response to the voltage control signal to open the target circuit by the shutdown signal. The electrostatic protection circuit is simple in structure, can bear higher electrostatic voltage and/or electrostatic current, can be used for electrostatic discharge protection of a high-voltage system, ensures the electrostatic protection effect, improves the reliability of the circuit, prolongs the service life of a target circuit, and is wide in application range.

Description

Electrostatic protection circuit, electrostatic protection method and integrated circuit

Technical Field

The present disclosure relates to electrostatic protection technologies, and in particular, to an electrostatic protection circuit, an electrostatic protection method, and an integrated circuit.

Background

Electrostatic Discharge (ESD) is the major cause of damage to all electronic components or integrated circuit systems due to Electrical Over Stress (EOS). Because the static electricity is usually very high in instantaneous voltage, which can reach thousands of volts or even tens of thousands of volts, the damage caused by the static electricity discharge is destructive and permanent, and the circuit can be directly burned.

Static electricity is usually generated artificially, and may be accumulated in human bodies, instruments or equipment, even components and parts themselves may accumulate static electricity in the processes of production, assembly, testing, storage, transportation and the like, and when people unknowingly make contact with charged objects, a discharge path is formed, so that electronic components or systems are damaged by static electricity discharge instantly. Therefore, in order to protect an electronic component or an integrated circuit, electrostatic protection is generally performed to prolong the service life of the electronic component or the integrated circuit.

However, the electrostatic protection circuit in the prior art has a large structural area, a complex structure, and limited impact of electrostatic voltage and/or electrostatic current, and has a non-ideal electrostatic protection effect on the high-voltage system, and cannot effectively perform electrostatic protection on the high-voltage system when electrostatic discharge occurs in the high-voltage system, which results in damage to the system circuit.

Disclosure of Invention

The application provides an electrostatic protection circuit, an electrostatic protection method and an integrated circuit, and aims to solve the problems that in the prior art, the electrostatic protection circuit is large in framework area, complex in structure, limited in impact of bearable electrostatic voltage and/or electrostatic current and not ideal in electrostatic protection effect on a high-voltage system.

In a first aspect, the present application provides an electrostatic protection circuit, which includes a trigger module, a leakage protection module, and a pull-down protection module, where the trigger module is electrically connected to the leakage protection module, the pull-down protection module, and a target circuit, and the leakage protection module and the pull-down protection module are electrically connected to the target circuit, respectively;

a trigger module configured to output a voltage control signal to the bleed-off protection module and the pull-down protection module in response to an electrostatic discharge signal of the target circuit;

a leakage protection module configured to form an electrostatic leakage path in response to the voltage control signal to discharge an electrostatic discharge signal of the target circuit through the electrostatic leakage path;

and the pull-down protection module is configured to respond to the voltage control signal and output a shutdown signal to the target circuit so as to open the target circuit through the shutdown signal.

In one possible implementation manner of the present application, the trigger module includes a voltage reduction unit and a voltage stabilization unit, which are electrically connected, the voltage reduction unit is electrically connected with the target circuit, and the voltage stabilization unit is electrically connected with the leakage protection module and the pull-down protection module, respectively;

the voltage reduction unit is used for reducing the voltage amplitude of the electrostatic discharge signal to obtain an intermediate voltage signal and outputting the intermediate voltage signal to the voltage stabilization unit;

and the voltage stabilizing unit is used for clamping the voltage amplitude of the intermediate voltage signal at a preset voltage value to obtain a voltage control signal and outputting the voltage control signal to the discharge protection module and the pull-down protection module.

In one possible implementation manner of the present application, the voltage reduction unit includes at least one diode, and the voltage stabilization unit includes at least one zener diode;

the at least one diode is connected in reverse series with the at least one zener diode and responsive to the electrostatic discharge signal, the at least one diode conducts in a forward direction and the at least one zener diode breaks down the regulated voltage in a reverse direction.

In one possible implementation manner of the present application, the bleeding protection module is configured with a bleeding on state and a bleeding off state, and the bleeding protection module is configured to:

and responding to the voltage control signal, and converting from the leakage cut-off state to the leakage conducting state to form an electrostatic leakage path between the target circuit and the grounding electrode.

In one possible implementation manner of the present application, the bleeding protection module includes a first transistor, and the first transistor multiplexes a power transistor in a target circuit;

the grid electrode of the first transistor is electrically connected with the trigger module and used for receiving the voltage control signal, the drain electrode of the first transistor is electrically connected with the target circuit, and the source electrode of the first transistor is electrically connected with the grounding electrode.

In one possible implementation manner of the present application, the pull-down protection module is configured with a pull-down on state and a pull-down off state, and the pull-down protection module is configured to:

and responding to the voltage control signal, and converting the pull-down cut-off state into a pull-down conducting state so as to output a cut-off signal to cut off a target switching device electrically connected with the pull-down protection module in the target circuit.

In one possible implementation manner of the present application, the pull-down protection module includes a switching transistor, a gate of the switching transistor is electrically connected to the trigger module and configured to receive a voltage control signal, a source of the switching transistor is electrically connected to a ground, and a drain of the switching transistor is electrically connected to a target switching device in a target circuit.

In one possible implementation manner of the present application, a voltage regulator diode is electrically connected between a gate and a source of the switching transistor, a cathode of the voltage regulator diode is electrically connected to the gate of the switching transistor, and an anode of the voltage regulator diode is electrically connected to the source of the switching transistor;

and the voltage stabilizing diode is used for clamping the voltage amplitude between the grid electrode and the source electrode of the switching transistor so as to protect the switching transistor.

In a second aspect, the present application further provides an electrostatic protection method, including:

responding to an electrostatic discharge signal of a target circuit, and outputting a voltage control signal to the leakage protection module and the pull-down protection module by the trigger module;

in response to the voltage control signal, the leakage protection module forms an electrostatic leakage path to discharge an electrostatic discharge signal of the target circuit through the electrostatic leakage path;

in response to the voltage control signal, the pull-down protection module outputs a shutdown signal to the target circuit to open the target circuit through the shutdown signal.

In a third aspect, the present application further provides an integrated circuit, which includes a target circuit and the electrostatic protection circuit of the first aspect, and the electrostatic protection circuit is electrically connected to the target circuit to perform electrostatic discharge protection on the target circuit.

From the above, the present application has the following advantageous effects:

in the application, a trigger module electrically connected with a target circuit monitors an electrostatic discharge signal of the target circuit, when the target circuit has the electrostatic discharge signal, the trigger module outputs a voltage control signal to a leakage protection module and a pull-down protection module in response to the electrostatic discharge signal, so that the leakage protection module forms an electrostatic leakage path in response to the voltage control signal to discharge electrostatic discharge of the target circuit, and protects the target circuit from being damaged by static electricity, and meanwhile, the pull-down protection module outputs a turn-off signal to the target circuit in response to the voltage control signal, so that the target circuit is disconnected to further protect components in the target circuit; the electrostatic protection circuit framework of this application is simple, step down the electrostatic discharge signal through trigger module, output voltage control signal to the protection module of bleeding and drop-down protection module, drive the protection module of bleeding and drop-down protection module and carry out electrostatic discharge protection to the target circuit, compare in the electrostatic protection circuit among the prior art, can bear higher electrostatic voltage and/or electrostatic current, can be used to high voltage system's electrostatic discharge protection, the electrostatic protection effect has been ensured, the circuit reliability has been improved, the life of target circuit has been prolonged, and wide application scope.

Drawings

In order to more clearly illustrate the technical solutions in the present application, the drawings that are needed to be used in the description of the present application will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive effort.

FIG. 1 is a schematic diagram of an integrated circuit provided in an embodiment of the present application;

FIG. 2 is a functional block diagram of an ESD protection circuit provided in an embodiment of the present application;

fig. 3 is a schematic diagram of another functional block of the electrostatic protection circuit provided in the embodiment of the present application;

FIG. 4 is a schematic circuit diagram of an ESD protection circuit provided in an embodiment of the present application;

fig. 5 is a schematic circuit diagram of a pull-down protection module provided in an embodiment of the present application;

fig. 6 is another schematic circuit diagram of a pull-down protection module provided in an embodiment of the present application;

fig. 7 is a schematic flow chart of an electrostatic protection method provided in an embodiment of the present application.

Wherein: the circuit comprises a 10-integrated circuit, a 20-target circuit, a 30-electrostatic protection circuit, a 40-trigger module, a 41-voltage reduction unit, a 42-voltage stabilization unit, a 50-leakage protection module, a 60-pull-down protection module and a 70-time sequence control unit.

Detailed Description

The technical solutions in the present application will be described clearly and completely with reference to the accompanying drawings in the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be considered as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the application. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known structures and processes are not set forth in detail in order to avoid obscuring the description of the present application with unnecessary detail. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

The present application provides an electrostatic protection circuit, an electrostatic protection method, and an integrated circuit, which will be described in detail below.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an integrated circuit 10 according to an embodiment of the present disclosure, where the integrated circuit 10 may include a target circuit 20 and an electrostatic protection circuit 30, and the electrostatic protection circuit 30 is electrically connected to the target circuit 20 to perform electrostatic discharge protection on the target circuit 20.

It is understood that the target circuit 20 may be a main circuit, a main chip, etc. integrated with a plurality of electronic components, which may be an internal circuit of the integrated circuit 10, and the target circuit 20 may control and implement corresponding product functions, because static electricity may be accumulated in the target circuit 20 during the production, assembly, test, storage, etc. of the target circuit, if a human body or other charged objects contact the target circuit 20 in some cases, a discharge path may be formed, so that the electronic components in the target circuit 20 may be damaged by electrostatic discharge.

Therefore, in the embodiment of the present application, the electrostatic protection circuit 30 is electrically connected to the target circuit 20 to drain the electrostatic current, so as to prevent the electrostatic current from entering the target circuit 20 and damaging the electronic components therein.

In the embodiment of the present application, the electrostatic protection circuit 30 may be electrically connected to any Input/Output (I/O) port of the target circuit 20.

As shown in fig. 1, the target circuit 20 may be configured with a Pin, which is a connection or an interface between the target circuit 20 and a peripheral circuit of the integrated circuit 10, when a charged human body or an object contacts the Pin, an electrostatic discharge signal, i.e., an electrostatic current, may be generated on the Pin immediately, if the target circuit 20 is not electrically connected to the electrostatic protection circuit 30, the electrostatic current generated on the Pin may directly flow into the target circuit 20, and if the electrostatic protection circuit 30 is connected between the target circuit 20 and the Pin in fig. 1, the electrostatic current may be drained by the electrostatic protection circuit 30, so that the electrostatic current flows to a ground electrode through the electrostatic protection circuit rather than flowing into the target circuit 20, and thus the electrostatic discharge protection circuit 30 may perform electrostatic discharge protection on the target circuit 20.

It is understood that when there is no electrostatic current or electrostatic discharge signal, the electrostatic protection circuit 30 of the embodiment of the present application does not operate or is in a standby state to ensure that the normal operation of the target circuit 20 is not affected.

Next, a detailed description is given to the electrostatic protection circuit 30 of the present application, please refer to fig. 2, fig. 2 is a functional block diagram of the electrostatic protection circuit provided in the embodiment of the present application, the electrostatic protection circuit 30 may include a trigger module 40, a pull-down protection module 50, and a pull-down protection module 60, the trigger module 40 may be electrically connected to the pull-down protection module 50, the pull-down protection module 60, and the target circuit 20, respectively, and the pull-down protection module 50 and the pull-down protection module 60 may be electrically connected to the target circuit 20, respectively.

The triggering module 40 may be configured to output a voltage control signal to the bleed protection module 50 and the pull-down protection module 60 in response to the electrostatic discharge signal of the target circuit 20.

The leakage protection module 50 may be configured to form an electrostatic leakage path in response to the voltage control signal to discharge the electrostatic discharge signal of the target circuit 20 through the electrostatic leakage path.

The pull-down protection module 60 may be configured to output a shutdown signal to the target circuit 20 in response to the voltage control signal to trip the target circuit 20 through the shutdown signal.

In the embodiment of the present application, when the electrostatic discharge signal out _ p is present at the Pin of the target circuit 20, the triggering module 40 may generate a voltage control signal in response to the esd signal out _ p, and specifically, the triggering module 40 may perform a voltage reduction process on the esd signal out _ p, so that the voltage amplitude of the voltage control signal is smaller than the voltage amplitude of the electrostatic discharge signal out _ p, when the target circuit 20 is applied to a high voltage system, the voltage amplitude of the electrostatic discharge signal out _ p is high, the esd signal out _ p may be stepped down by the triggering module 40, so as to ensure that the esd protection circuit 30 can work normally, the target circuit 20 is protected by electrostatic discharge, and after the trigger module 40 drops the electrostatic discharge signal out _ p, a voltage control signal may be obtained for output to the bleed down protection module 50 and the pull down protection module 60.

It can be understood that when the esd signal out _ p is not present at the Pin, the triggering module 40 in the embodiment of the present application does not operate because there is no input signal or driving signal, and at this time, the bleeding protection module 50 and the pull-down protection module 60 also do not operate because there is no driving signal, such as the voltage control signal.

Since the esd protection circuit 30 needs to drain the esd signal out _ p generated at the Pin to prevent the esd signal out _ p from being input to the target circuit 20, when the leakage protection module 50 receives the voltage control signal from the trigger module 40, it may be determined that the esd signal exists in the circuit at this time, and the leakage protection module 50 may form an esd path in response to the received voltage control signal, so that the esd signal out _ p generated at the Pin may be discharged through the esd path to prevent the esd signal out _ p from being input to the target circuit 20, thereby implementing esd protection on the target circuit 20.

In order to further ensure the safety of the target circuit 20 while the leakage protection module 50 is leaking the electrostatic discharge signal out _ p through the electrostatic leakage path, in the embodiment of the present application, the pull-down protection module 60 may generate a shutdown signal to be output to the target circuit 20 in response to the voltage control signal output by the trigger module 40, so as to open the target circuit 20 through the shutdown signal, thereby ensuring that no current flows through the target circuit 20 at this time, and ensuring the absolute safety of the target circuit 20.

In the present application, the trigger module 40 electrically connected to the target circuit 20 monitors the electrostatic discharge signal out _ p at the Pin of the target circuit 20, and when there is an electrostatic discharge signal, the trigger module 40 outputs a voltage control signal to the bleeding protection module 50 and the pull-down protection module 60 in response to the electrostatic discharge signal out _ p, so that the bleeding protection module 50 forms an electrostatic bleeding path in response to the voltage control signal to bleed off the electrostatic discharge signal out _ p, thereby protecting the target circuit 20 from being damaged by static electricity, and at the same time, the pull-down protection module 60 outputs a shutdown signal to the target circuit 20 in response to the voltage control signal, so that the target circuit 20 is disconnected to further protect the components in the target circuit 20; the electrostatic protection circuit 30 of the present application has a simple structure, step down the electrostatic discharge signal out _ p through the trigger module 40, output the voltage control signal with the voltage amplitude smaller than the electrostatic discharge signal to the discharge protection module 50 and the pull-down protection module 60, drive the discharge protection module 50 and the pull-down protection module 60 to perform electrostatic discharge protection on the target circuit 20, compared with the electrostatic protection circuit in the prior art, the electrostatic protection circuit can bear higher electrostatic voltage and/or electrostatic current, can be used for electrostatic discharge protection of a high-voltage system, ensure an electrostatic protection effect, improve circuit reliability, prolong service life of the target circuit, and has a wide application range.

It should be noted that, in some application scenarios, if there is no component with electrostatic breakdown risk in the target circuit 20, the trigger module 40 may only output a voltage control signal to the leakage protection module 50, and at this time, the pull-down protection module 60 may not operate, and only the leakage protection module 50 leaks an electrostatic discharge signal generated in the target circuit 20, so as to perform electrostatic discharge protection on the target circuit 20.

If there are components in the target circuit 20 that have electrostatic breakdown risks, the trigger module 40 may output voltage control signals to the bleeding protection module 50 and the pull-down protection module 60 at the same time, so that the bleeding protection module 50 and the pull-down protection module 60 respectively respond to the voltage control signals to operate, and perform electrostatic discharge protection on the target circuit 20.

Referring to fig. 3, fig. 3 is a schematic diagram of another functional block of the esd protection circuit provided in the embodiment of the present application, in some embodiments of the present application, the trigger module 40 may include a voltage-reducing unit 41 and a voltage-stabilizing unit 42 electrically connected, the voltage-reducing unit 41 is electrically connected to the target circuit 20, and the voltage-stabilizing unit 42 is electrically connected to the leakage protection module 50 and the pull-down protection module 60, respectively.

The voltage reducing unit 41 may be configured to reduce a voltage amplitude of the electrostatic discharge signal, obtain an intermediate voltage signal, and output the intermediate voltage signal to the voltage stabilizing unit 42; the voltage stabilizing unit 42 may be configured to clamp the voltage amplitude of the intermediate voltage signal at a preset voltage value, and output a voltage control signal to the bleeding protection module 50 and the pull-down protection module 60.

In the embodiment of the present application, the voltage reduction unit 41 may reduce the voltage amplitude of the electrostatic discharge signal out _ p, and the voltage reduction unit 41 may be an electronic component having a voltage drop, and performs voltage reduction processing on the electrostatic discharge signal out _ p through the voltage drop of the electronic component itself; or may be an existing voltage converter, by which the electrostatic discharge signal out _ p of a certain voltage magnitude is stepped down to an intermediate voltage signal of another voltage magnitude.

In the embodiment of the present application, the voltage stabilizing unit 42 may clamp the voltage amplitude of the intermediate voltage signal at a preset voltage value, and as can be understood, the voltage stabilizing unit 42 may be an electronic component with a clamping or voltage stabilizing effect, so as to reduce the voltage of the intermediate voltage signal with a relatively high voltage amplitude into a voltage control signal through the voltage stabilizing unit 42, and then the voltage control signal drives the discharging protection module 50 and the pull-down protection module 60 to work.

In a specific implementation, the voltage dropping unit 41 may include a voltage converter, and the voltage converter may be configured to drop the electrostatic discharge signal with a higher voltage amplitude, for example, 15000V, into an intermediate voltage signal with a lower voltage amplitude, and output the intermediate voltage signal to the voltage stabilizing unit 42.

In one specific implementation, the voltage dropping unit 41 may include at least one diode, and the voltage stabilizing unit 42 may include at least one zener diode; wherein the at least one diode is connected in reverse series with the at least one zener diode and responsive to the electrostatic discharge signal, the at least one diode conducts in a forward direction and the at least one zener diode breaks down the regulated voltage in a reverse direction. Referring to fig. 4, fig. 4 is a schematic circuit diagram of an electrostatic protection circuit provided in the embodiment of the present application, in the embodiment, the voltage-reducing unit 41 includes three diodes connected in series in the same direction, that is, a first diode D1, a second diode D2, and a third diode D3, the voltage-stabilizing unit 42 includes two zener diodes connected in series in the same direction, that is, a fourth zener diode D4 and a fifth zener diode D5, wherein an anode of the first diode D1 is electrically connected to a Pin of the target circuit 20, a cathode of the third diode D3 is electrically connected to a cathode of the fourth zener diode D4, an anode of the fifth zener diode D5 is connected to a first resistor R1 connected to ground, and an anode of the fifth zener diode D5 is further connected to the bleeder protection module 50 and the pull-down protection module 60.

When the electrostatic discharge signal out _ p exists at the Pin of the target circuit 20, since the voltage amplitude of the electrostatic discharge signal out _ p is high, at this time, the fourth zener diode D4 and the fifth zener diode D5 break down in the reverse direction, the first diode D1, the second diode D2 and the third diode D3 are all turned on in the forward direction, and when the electrostatic discharge signal out _ p passes through the first diode D1, the second diode D2 and the third diode D3, since the first diode D1, the second diode D2 and the third diode D3 have a voltage drop, the voltage amplitude of the intermediate voltage signal output from the cathode of the third diode D3 is a value obtained by subtracting the voltage drops of the first diode D1, the second diode D2 and the third diode D3 from the voltage amplitude of the electrostatic discharge signal out _ p, at this time, since the fourth zener diode D4 and the fifth zener diode D5 break down in the reverse direction, based on the operating principle of the zener diodes, the voltage amplitude of the intermediate voltage signal is stable, specifically, the voltage amplitude is related to the breakdown voltages of the fourth zener diode D4 and the fifth zener diode D5, that is, the preset voltage value is related to the breakdown voltages of the fourth zener diode D4 and the fifth zener diode D5, the anode of the fifth zener diode D5 outputs the voltage control signal to the bleeder protection module 50 and the pull-down protection module 60, and the potential of the upper end of the first resistor R1, that is, the point a, rises.

It should be noted that, the voltage dropping unit 41 of the present application may further include more or less diodes than those shown in fig. 4, and the voltage stabilizing unit 42 may further include more or less zener diodes than those shown in fig. 4, and the number of diodes of the voltage dropping unit 41 and the number of zener diodes of the voltage stabilizing unit 42 may be selected according to practical application scenarios, and is not limited herein.

Continuing to refer to fig. 3, in some embodiments of the present application, the bleed protection module 50 may be configured with a bleed on state and a bleed off state, and the bleed protection module 50 may be configured to: the leakage off state is converted to the leakage on state in response to the voltage control signal to form an electrostatic leakage path between the target circuit 20 and the ground electrode.

In the embodiment of the present application, when the electrostatic discharge signal out _ p does not exist in the circuit, the voltage control signal does not exist correspondingly, and the leakage protection module 50 may be in a leakage off state without driving the voltage control signal, when the esd signal out _ p exists at the Pin of the target circuit 20, the trigger module 40 outputs a voltage control signal to the bleeding protection module 50, and the bleeding protection module 50 can switch from a bleeding off state to a bleeding on state in response to the voltage control signal, at this time, since the leakage protection module 50 is also electrically connected to the target circuit 20, the leakage protection module 50 in the leakage conducting state may form an electrostatic leakage path between the target circuit 20 and the ground electrode, so as to drain and discharge the electrostatic discharge signal out _ p at the Pin of the target circuit 20, thereby preventing the electrostatic discharge signal out _ p from being input into the target circuit 20.

With continued reference to fig. 4, in one implementation, the bleeder protection module 50 may include a first transistor M1, the first transistor M1 multiplexing a power transistor in the target circuit 20; the gate of the first transistor M1 is electrically connected to the trigger module 40 for receiving the voltage control signal, the drain of the first transistor M1 is electrically connected to the target circuit, and the source of the first transistor M1 is electrically connected to the ground GND.

Specifically, in the embodiment of the present application, the first transistor M1 may multiplex an existing switching power transistor in the target circuit 20, for example, a power transistor in a class D power amplifier, that is, a field effect transistor, at this time, a unidirectional conducting unit may be electrically connected between the bleeding protection module 50 and the trigger module 40, the unidirectional conducting unit may include a sixth diode D6, wherein an anode of the sixth diode D6 is electrically connected to an anode of the fifth zener diode D5, a voltage control signal output by the anode of the fifth zener diode D5 is input to the sixth diode D6 to be conducted, a voltage driving signal Vdrv _ n is output to the gate of the first transistor M1 after being stepped down by the sixth diode D6, the gate of the first transistor M1 is responsive to the voltage driving signal Vdrv _ n to make the drain of the first transistor M1 and the source conduct, and since the drain of the first transistor M1 is electrically connected to the target circuit 20, the source of the first transistor M1 is electrically connected to the ground GND, the turned-on first transistor M1 grounds the Pin of the target circuit 20 to form an electrostatic discharge path, and the electrostatic discharge signal out _ p at the Pin of the target circuit 20 flows into the ground GND through the turned-on first transistor M1 to perform an electrostatic discharge protection function on the target circuit 20.

It can be understood that, if the first transistor M1 is multiplexed with the existing switching power transistor in the target circuit 20, when the target circuit 20 normally operates, the first transistor M1 may normally operate, and at this time, because no esd signal is generated in the target circuit 20 and the esd protection circuit 30 does not operate, in this embodiment of the present application, the gate of the first transistor M1 is isolated from the ground GND by the sixth diode D6, so as to avoid that when no esd signal is generated in the target circuit 20, the gate of the first transistor M1 is directly connected to the ground GND, so that the gate of the first transistor M1 is always pulled low, which causes the first transistor M1 not to normally operate, and through the unidirectional conduction characteristic of the sixth diode D6, when no esd signal is generated in the target circuit 20, the first transistor M1 can be ensured to be normally turned on and off, and at the same time, when an esd signal is present in the target circuit 20, the sixth diode D6 is ensured to be capable of conducting and outputting the voltage driving signal Vdrv _ n to the gate of the first transistor M1, so that the first transistor M1 is conducted to form an electrostatic discharge path.

It should be noted that, if the first transistor M1 is an independent switching power transistor, instead of an existing switching power transistor in the multiplexing target circuit 20, it is no longer necessary to isolate the gate of the first transistor M1 from the ground GND through the sixth diode D6, and therefore, the arrangement of the sixth diode D6 may be determined according to an actual application scenario.

It can be understood that, when the power switch tube exists in the target circuit 20, multiplexing the power switch tube therein can save a large amount of chip area, simplify circuit routing, and implement electrostatic discharge protection for the target circuit 20, and because the crystal source is expensive, multiplexing the power switch tube saves chip area and can also save cost to a great extent; if the power switch tube is not present in the target circuit 20, the electrostatic discharge protection of the target circuit 20 can be realized by the first transistor M1 alone in the electrostatic protection circuit 30, that is, the electrostatic protection circuit 30 of the embodiment of the present application is not limited by the structure of the target circuit 20, and the electrostatic discharge protection of the target circuit 20 can be realized.

As shown in fig. 4, in some embodiments of the present application, the voltage control signal output by the anode of the fifth zener diode D5 may be further filtered by an RC filter, specifically, the RC filter may include a second resistor R2 and a first capacitor C1 to ground, wherein one end of the second resistor R2 is electrically connected to the anode of the fifth zener diode D5, and the other end is electrically connected to the first capacitor C1, and meanwhile, if the sixth diode D6 exists, the other end is also electrically connected to the anode of the sixth diode D6, and if the sixth diode D6 does not exist, the other end is also electrically connected to the gate of the first transistor M1, so as to filter out noise included in the voltage control signal.

In this embodiment, the electrostatic discharge signal out _ P is a pulse signal, the first Transistor M1 is an N-channel Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET), which is referred to as an NMOS Transistor for short, and in some other application scenarios, the first Transistor M1 may also be a P-channel MOS Transistor, an Insulated Gate Bipolar Transistor (IGBT), a thyristor, a triode, or other controllable switching devices, and the type of the first Transistor M1 may be selected according to an actual application scenario, and is not limited herein. As shown in fig. 3, in some embodiments of the present application, the pull-down protection module 60 may be configured with a pull-down on state and a pull-down off state, and the pull-down protection module 60 may be configured to: the pull-down off state is converted into the pull-down on state in response to the voltage control signal to output an off signal to turn off a target switching device of the target circuit 20 electrically connected to the pull-down protection module 60.

In this embodiment, when there is no electrostatic discharge signal out _ p in the circuit, there is no corresponding voltage control signal, and there is no driving of the voltage control signal, the pull-down protection module 60 does not operate, the pull-down protection module 60 may be in a pull-down off state, and when there is an electrostatic discharge signal out _ p at the Pin of the target circuit 20, the trigger module 40 outputs a voltage control signal to the pull-down protection module 60, and the pull-down protection module 60 may be switched from the pull-down off state to a pull-down on state in response to the voltage control signal, at this time, because the pull-down protection module 60 is also electrically connected to the target switching device in the target circuit 20, the pull-down protection module 60 in the pull-down on state may output a turn-off signal to the target switching device in the target circuit 20 to drive the target switching device to turn off, so as to make the branch where the target switching device is located open, protecting the target switching device and its electronic components in the branch of the target circuit 20.

In one implementation, the pull-down protection module 60 may include a switching transistor having a gate electrically connected to the trigger module 40 for receiving the voltage control signal, a source electrically connected to ground, and a drain electrically connected to a target switching device in the target circuit 20.

Specifically, as shown in fig. 4, the pull-down protection module 60 may include a switch transistor M2, wherein the gate of the switch transistor M2 is electrically connected to the output terminal of the trigger module 40, for example, a point a, the source of the switch transistor M2 is electrically connected to the ground GND, the drain of the switch transistor M2 is electrically connected to the gate of the target switch device P1 in the target circuit 20, and when there is no esd signal out _ P, since there is no voltage control signal output at the point a, the switch transistor M2 is in an off state, and the drain and the source of the switch transistor M2 are disconnected; when the electrostatic discharge signal out _ P exists, the voltage control signal is outputted to the gate of the switching transistor M2 at the point a, the switching transistor M2 makes the drain and the source thereof conductive in response to the voltage control signal, since the source of the switching transistor M2 is electrically connected to the ground GND, the drain of the switching transistor M2 is equivalent to the ground after being conductive, and since the drain of the switching transistor M2 is electrically connected to the gate of the target switching device P1 in the target circuit 20, the gate of the target switching device P1 is equivalent to the ground at this time, that is, the off signal outputted from the drain of the switching transistor M2 to the target switching device P1 is a signal for pulling down the potential of the gate of the target switching device P1 to the ground GND, the target switching device P1 is immediately turned off in response to the off signal, and the branch of the target switching device P1 in the target circuit 20 is opened at this time, in this way, no current flows through the electronic components of the branch where the target switching device P1 is located, and the safety of the target circuit 20 is further ensured.

In this embodiment, the switch Transistor M2 is an N-channel MOS Transistor, and it should be noted that in some other application scenarios, the switch Transistor M2 may also be a controllable switch device such as a PMOS Transistor, an Insulated Gate Bipolar Transistor (IGBT), a thyristor, a triode, and the like, and the type of the switch Transistor M2 may be selected according to an actual application scenario, and is not limited herein.

It should be noted that only one switching transistor M2 is shown in fig. 4, and it is understood that the pull-down protection module 60 according to the embodiment of the present application may further include more switching transistors than those shown in fig. 4, each of the switching transistors may be correspondingly connected to the gate of the switching device in the target circuit 20, so that the state of the corresponding switching device may be controlled by each of the switching transistors, and in some other application scenarios, one switching transistor may also be electrically connected to the gates of a plurality of switching devices in the target circuit 20, so that the states of the plurality of switching devices may be controlled simultaneously by the one switching transistor.

With continued reference to fig. 3, in some embodiments of the present application, the electrostatic protection circuit 30 may further include a timing control unit 70, the timing control unit 70 may be electrically connected to a target switching device in the target circuit 20, and the timing control unit 70 may be configured to output a timing control signal to the target switching device in response to an operation signal of the target circuit 20 so as to operate the target switching device.

In this embodiment, when the target circuit 20 normally operates, that is, when there is no electrostatic discharge signal in the target circuit 20, the timing control unit 70 may output a timing control signal to the target switching device in response to an operating signal of the target circuit 20, so that the target switching device may be switched to a conducting state according to the timing control signal, and the target switching device and the branch where the target switching device is located may normally operate.

Referring to fig. 5, fig. 5 is a schematic circuit diagram of a pull-down protection module provided in the embodiment of the present application, and in a specific implementation, the target switch device P1 may be a first N-channel transistor M4, and the switch transistor M2 is an NMOS transistor, it can be understood that, for an N-channel transistor, when a voltage difference between a gate voltage and a source voltage of the N-channel transistor is higher than a predetermined threshold voltage, the N-channel transistor is turned on, and conversely, the N-channel transistor is turned off.

The output terminal of the timing control unit 70 may be electrically connected to the gate of the first N-channel transistor M4, the source of the first N-channel transistor M4 is electrically connected to the ground GND, and the timing control signal output by the timing control unit 70 may be a high level signal which may be directly input to the gate of the first N-channel transistor M4 to put the first N-channel transistor M4 in a target on state when the target circuit 20 normally operates.

It is understood that the timing control signal outputted by the timing control unit 70 may also be a low level signal, as shown in fig. 4, the low level signal may be inverted into a high level signal by the not logic circuit U1, and then inputted to the gate of the first N-channel transistor M4 via the fifth resistor R5, so that the first N-channel transistor M4 is in a target on state.

When the target circuit 20 is normally operated, the state of the first N-channel type transistor M4 should be controlled by the timing control signal output from the timing control unit 70, and the switching transistor M2 should be in an off state at this time; when there is an esd signal in the target circuit 20, if the target branch where the first N-channel transistor M4 is located is a branch having a safety risk, for example, if there is a component easily broken down by static electricity, the target branch needs to be opened when an esd event occurs, so as to prevent current from flowing through the target branch.

In the embodiment of the present application, when there is an esd signal in the target circuit 20, the triggering module 40 outputs a voltage control signal to the switching transistor M2 in response to the esd signal, at this time, the voltage control signal is a high level signal, the switching transistor M2 switches from an off state to an on state in response to the high level signal, at this time, the drain and the source of the switching transistor M2 are turned on, since the source of the switching transistor M2 is electrically connected to the ground GND, the potential of the gate of the first N-channel transistor M4 is pulled low, so that the first N-channel transistor M4 is switched from the target on state to the target off state, and the first N-channel transistor M4 is ensured to be turned off, and the target branch where the first N-channel transistor M4 is located is disconnected when the first N-channel transistor M4 is turned off, thereby preventing a current from flowing through the target branch, thereby playing the role of electrostatic discharge protection.

Referring to fig. 6, fig. 6 is another schematic circuit diagram of the pull-down protection module provided in the embodiment of the present application, in one specific implementation, the target switch device P1 is a first P-channel transistor M3, and the switch transistor M2 is a PMOS transistor, it can be understood that, for the P-channel transistor, when a voltage difference between a gate voltage and a source voltage of the P-channel transistor is lower than a predetermined threshold voltage, the P-channel transistor is turned on, and otherwise, the P-channel transistor is turned off.

The output terminal of the timing control unit 70 may be electrically connected to the gate of the first P-channel transistor M3, the source of the first P-channel transistor M3 may be electrically connected to the power supply terminal PVDD, the drain of the first P-channel transistor M3 is electrically connected to the ground GND through the second zener diode D9, and when the target circuit 20 normally operates, the timing control signal output by the timing control unit 70 may be a low-level signal, which may be directly input to the gate of the first P-channel transistor M3, so that the first P-channel transistor M3 is in a target on state.

It is understood that the timing control signal outputted by the timing control unit 70 may also be a high level signal, as shown in fig. 6, the high level signal may be inverted into a low level signal by the not logic circuit U2, and then inputted to the gate of the first P-channel transistor M3 via the sixth resistor R6, so that the first P-channel transistor M3 is in a target on state.

When the target circuit 20 is normally operated, the state of the first P-channel type transistor M3 should be controlled by the timing control signal output from the timing control unit 70, and the switching transistor M2 should be in an off state at this time; when there is an esd signal in the target circuit 20, if the target branch where the first P-channel transistor M3 is located is a branch having a safety risk, the target branch needs to be disconnected when an esd event occurs, so as to prevent a current from flowing through the target branch.

In the embodiment of the present application, when there is an esd signal in the target circuit 20, the trigger module 40 outputs a voltage control signal to the switch transistor M2 in response to the esd signal, and at this time, the voltage control signal may be a low level signal, for example, an inverter is disposed between the trigger module 40 and the switch transistor M2, and the inverter inverts the high level voltage control signal output at the point a in fig. 3 into a low level signal, the switch transistor M2 switches from an off state to an on state in response to the low level signal, and at this time, the drain and the source of the switch transistor M2 are turned on, and since the source of the switch transistor M2 is electrically connected to the power supply terminal PVDD, the potential of the gate of the first P-channel transistor M3 is raised, so that the first P-channel transistor M3 is switched from the target on state to the target off state, and the first P-channel transistor M3 is ensured to be turned off, and when the first P-channel transistor M3 is turned off, the target branch where the first P-channel transistor M3 is located is open-circuited, so as to prevent current from flowing through the target branch, thereby performing the electrostatic discharge protection function.

It should be understood that the circuit structure within the dashed line frame in fig. 5 and fig. 6 is an internal circuit structure of the target circuit 20, and is not a focus of the present application, and therefore, it is not described in detail herein in the embodiment of the present application, and it should be noted that the internal circuit structure of the target circuit 20 shown in fig. 5 and fig. 6 does not constitute a limitation to the circuit structure of the target circuit 20 of the present application, and the target circuit 20 of the present application may also be another circuit structure, and is not limited herein.

In some embodiments of the present application, the target circuit 20 may include at least one power domain, and the target switching device is connected in series between the at least one power domain and the ground, please refer to fig. 5 and fig. 6, in which the target circuit 20 may include three power domains, namely, a power source terminal PVDD, a second power source terminal PVDDM5V and a third power source terminal VCLIP5V, in the embodiments of the present application, the electrostatic protection circuit 30 may be disposed between the power source terminal PVDD and the third power source terminal VCLIP5V and between the PVDDM5V and the ground GND, and it is understood that, when other power domains exist in the target circuit 20, the electrostatic protection circuit 30 in the embodiments of the present application may also be disposed between the other power domains and the ground GND to perform electrostatic discharge protection on the target circuit 20 through the electrostatic protection circuit 30.

In addition, as shown in fig. 5, the drain of the first N-channel transistor M4 is electrically connected to a first zener diode D8, when an electrostatic discharge event occurs in the target circuit 20, the first zener diode D8 breaks down the zener voltage in the reverse direction, and at the same time, as shown by an arrow in fig. 5, the target branch formed by the first zener diode D8 and the first N-channel transistor M4 has a safety risk, and the electrostatic protection circuit 30 according to the embodiment of the present application turns off the first N-channel transistor M4, thereby ensuring the safety of the target branch.

Similarly, as shown in fig. 6, the drain of the first P-channel transistor M3 is electrically connected to the second zener diode D9, when an esd event occurs in the target circuit 20, the second zener diode D9 breaks down the regulated voltage in the reverse direction, and at the same time, the target branch formed by the second zener diode D9 and the first P-channel transistor M3 is as shown by the arrow in fig. 6, which has a safety risk, and the electrostatic protection circuit 30 according to the embodiment of the present application turns off the first P-channel transistor M3, so as to ensure the safety of the target branch.

In the prior art, a Resistor-capacitor (RC) type electrostatic clamp circuit and/or a Silicon-Controlled Rectifier (SCR) are generally arranged to discharge an electrostatic current existing in a high-voltage circuit, so as to protect the high-voltage circuit.

However, due to the existence of the high-power device in the high-voltage circuit, when the circuit normally works, due to the existence of parasitic parameters in the circuit, such as parasitic resistance and/or parasitic capacitance, large voltage jitter exists at the power end and the ground end, and the voltage jitter can cause the RC-type electrostatic clamp circuit and the silicon controlled rectifier to be triggered by mistake, so that the RC-type electrostatic clamp circuit and the branch where the silicon controlled rectifier is located are short-circuited, and the high-voltage circuit is burned out.

The electrostatic protection circuit 30 of the embodiment of the application can realize 15000V high-voltage electrostatic protection through different types of components in the circuit, and the target branch circuit in the target circuit 20 is controlled to be open-circuited through the pull-down protection module 60, thereby further performing electrostatic discharge protection on the target circuit 20, voltage jitter caused by parasitic parameters in the circuit can be avoided, further, the circuit is prevented from being triggered by mistake, the reliability and the electrostatic protection effect of the electrostatic protection circuit 30 are ensured, and due to no time delay, the electrostatic discharge signal in the target circuit 20 can be responded in time, the response speed is increased, and the service life of the target circuit 20 is prolonged.

With continued reference to fig. 4, in some embodiments of the present application, a zener diode D7 may be electrically connected between the gate and the source of the switching transistor M2, the cathode of the zener diode D7 is electrically connected to the gate of the switching transistor M2, and the anode of the zener diode D7 is electrically connected to the source of the switching transistor M2; the zener diode D7 may be used to clamp the magnitude of the voltage between the gate and source of the switch transistor M2 to protect the switch transistor M2.

It can be understood that when the esd signal out _ p exists in the circuit, the potential at the point a may be higher than the tolerable voltage of the gate of the switch transistor M2, and at this time, the gate of the switch transistor M2 may be damaged due to overvoltage, so in the embodiment of the present application, the potential at the gate of the switch transistor M2 is clamped by the zener diode D7 whose anode is grounded, so that the magnitude of the voltage between the gate and the source of the switch transistor M2 is maintained at a certain value, and the switch transistor M2 is prevented from being damaged.

Specifically, the clamping voltage, i.e., the magnitude of the voltage between the gate and the source of the switching transistor M2, may be determined according to the performance parameters of the zener diode D7, since the zener diode is made by using the characteristic that when the PN junction is reverse-broken, the current can be varied over a wide range while the voltage is substantially maintained, therefore, when the reverse voltage of the zener diode D7 is higher than the reverse voltage critical value, the zener diode D7 breaks down in the reverse direction, and at this time, the voltage across the zener diode D7 may be stabilized around the breakdown voltage, that is, the magnitude of the voltage between the gate and the source of the switching transistor M2 can be determined according to the breakdown voltage of the zener diode D7, if the breakdown voltage of the zener diode D7 is 5.5V, the voltage at point a or the gate of the switching transistor M2 can be stabilized at about 5.5V by the zener diode D7 to avoid over-voltage on the gate of the switching transistor M2.

Referring to fig. 7, fig. 7 is a schematic flow chart of an electrostatic protection method provided in an embodiment of the present application, and based on the electrostatic protection circuit, an embodiment of the present application further provides an electrostatic protection method, where an execution subject of the electrostatic protection method may be an electrostatic protection circuit, and the electrostatic protection method may include the following steps:

step S701, responding to an electrostatic discharge signal of a target circuit, and outputting a voltage control signal to a leakage protection module and a pull-down protection module by a trigger module;

step S702, in response to the voltage control signal, the leakage protection module forms an electrostatic leakage path to discharge an electrostatic discharge signal of the target circuit through the electrostatic leakage path;

step S703, in response to the voltage control signal, the pull-down protection module outputs a shutdown signal to the target circuit to open the target circuit through the shutdown signal.

It should be noted that, although a logical order is shown in the flow chart, in some cases, the steps shown or described may be executed in an order different from that here, for example, step S502 and step S503 may be executed simultaneously or may be executed before or after a certain delay.

In addition, in the present application, the relevant contents of the electrostatic protection methods described in steps S701 to S703 correspond to the electrostatic protection circuits one to one, and it can be clearly understood by those skilled in the art that, for convenience and simplicity of description, the specific working processes of the corresponding unit modules in the electrostatic protection methods described above may refer to the descriptions of the electrostatic protection circuits in any embodiment corresponding to fig. 1 to 6, and are not described herein again in detail.

It should be understood that the circuits shown in fig. 1 to 6 and the units and modules thereof may be implemented in various ways. For example, in some embodiments, a module and its elements may be implemented in hardware, software, or a combination of software and hardware. Wherein the hardware portion may be implemented using dedicated logic circuitry; the software portions may be stored in a memory for execution by a suitable instruction execution system, such as a microprocessor or specially designed hardware.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and parts that are not described in detail in a certain embodiment may refer to the above detailed descriptions of other embodiments, and are not described herein again.

In a specific implementation, each unit or structure may be implemented as an independent entity, or may be combined arbitrarily to be implemented as one or several entities, and the specific implementation of each unit or structure may refer to the foregoing embodiments, which are not described herein again.

The electrostatic protection circuit, the electrostatic protection method, and the integrated circuit provided in the present application are described in detail above, and specific examples are applied in the present application to explain the principles and embodiments of the present application, and the above description is only used to help understand the circuit, method, and core ideas of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. The electrostatic protection circuit is characterized by comprising a trigger module, a leakage protection module and a pull-down protection module, wherein the trigger module is respectively and electrically connected with the leakage protection module, the pull-down protection module and a target circuit;

the trigger module is configured to respond to an electrostatic discharge signal of the target circuit and output a voltage control signal to the leakage protection module and the pull-down protection module;

the leakage protection module is configured to respond to the voltage control signal and form an electrostatic leakage path so as to discharge an electrostatic discharge signal of the target circuit through the electrostatic leakage path;

the pull-down protection module is configured to respond to the voltage control signal and output a shutdown signal to the target circuit so as to open the target circuit through the shutdown signal.

2. The electrostatic protection circuit according to claim 1, wherein the trigger module comprises a voltage reduction unit and a voltage stabilization unit which are electrically connected, the voltage reduction unit is electrically connected with the target circuit, and the voltage stabilization unit is electrically connected with the leakage protection module and the pull-down protection module respectively;

the voltage stabilizing unit is configured to clamp the voltage amplitude of the intermediate voltage signal at a preset voltage value, obtain the voltage control signal, and output the voltage control signal to the bleeding protection module and the pull-down protection module.

3. The ESD protection circuit of claim 2 wherein the voltage-reducing unit comprises at least one diode, and the voltage-stabilizing unit comprises at least one Zener diode;

the at least one diode is connected in reverse series with the at least one zener diode and is forward conducting in response to the electrostatic discharge signal, the at least one zener diode breakdown in reverse to a regulated voltage.

4. The electrostatic protection circuit of claim 1, wherein the bleed protection module is configured with a bleed on state and a bleed off state, the bleed protection module configured to:

and responding to the voltage control signal, and converting the leakage cut-off state into the leakage conducting state to form an electrostatic leakage path between the target circuit and a grounding electrode.

5. The ESD protection circuit of claim 4 wherein the leakage protection module includes a first transistor that multiplexes a power transistor in the target circuit;

6. The electrostatic protection circuit of claim 1, wherein the pull-down protection module is configured with a pull-down on state and a pull-down off state, the pull-down protection module configured to:

and responding to the voltage control signal, converting the pull-down cut-off state into the pull-down conducting state to output the turn-off signal so as to turn off a target switching device in the target circuit, which is electrically connected with the pull-down protection module.

7. The ESD protection circuit of claim 6 wherein the pull-down protection module comprises a switching transistor, a gate of the switching transistor is electrically connected to the trigger module for receiving the voltage control signal, a source of the switching transistor is electrically connected to ground, and a drain of the switching transistor is electrically connected to the target switching device in the target circuit.

8. The electrostatic protection circuit according to claim 7, wherein a zener diode is electrically connected between the gate and the source of the switching transistor, a cathode of the zener diode is electrically connected to the gate of the switching transistor, and an anode of the zener diode is electrically connected to the source of the switching transistor;

the voltage stabilizing diode is used for clamping the voltage amplitude between the grid electrode and the source electrode of the switch transistor so as to protect the switch transistor.

9. An electrostatic protection method, comprising:

in response to the voltage control signal, the leakage protection module forms an electrostatic leakage path to leak an electrostatic discharge signal of the target circuit through the electrostatic leakage path;

10. An integrated circuit comprising a target circuit and the electrostatic protection circuit of any of claims 1-8, the electrostatic protection circuit being electrically connected to the target circuit for electrostatic discharge protection of the target circuit.