CN117498845A

CN117498845A - Low leakage switch and chip

Info

Publication number: CN117498845A
Application number: CN202311577709.3A
Authority: CN
Inventors: 陈原; 王建
Original assignee: Shanghai Analog Semiconductor Technology Co ltd
Current assignee: Shanghai Analog Semiconductor Technology Co ltd
Priority date: 2023-11-23
Filing date: 2023-11-23
Publication date: 2024-02-02

Abstract

The embodiment of the application provides a low-leakage switch and a chip, wherein the low-leakage switch comprises a transistor and a voltage control module. The drain electrode of the transistor is electrically connected with the input end of the voltage control module and the output end of the low leakage switch, the source electrode of the transistor is electrically connected with the first output end of the voltage control module and the input end of the low leakage switch, the grid electrode of the transistor is electrically connected with the second output end of the voltage control module, and the voltage control module can control the grid electrode voltage and the source electrode voltage of the transistor so as to reduce the drain electrode current of the transistor. The low-leakage switch provided by the embodiment of the application can reduce leakage current in a circuit.

Description

Low leakage switch and chip

Technical Field

The embodiment of the application relates to the technical field of protection circuits, in particular to a low-leakage switch and a chip.

Background

With the use of electrical appliances in life, electrostatic discharge is also a common phenomenon. Electrostatic discharge (Electrostatic Discharge, ESD) can occur during manufacture or use of the appliance. Since the transient voltage of electrostatic discharge is usually very high (> several kilovolts), the damage of the components caused by electrostatic discharge is destructive and permanent, and can cause the integrated circuit to burn out directly. Thus, prevention of electrostatic damage is a first challenge in the design and manufacture of all integrated circuits.

The current solution to the electrostatic discharge phenomenon is to provide protection hardware for the circuit at the time of manufacturing the chip. The common protection hardware such as a diode is in a cut-off state when the diode normally works by using the circuit, the normal work of the circuit is not affected, when the circuit is abnormally over-voltage and reaches the breakdown voltage, the circuit is rapidly conducted to enable instantaneous current to flow out, and meanwhile, the abnormal high voltage is clamped within a safe level, so that the protected integrated circuit or circuit is protected.

However, the diode is not completely ideally turned off when it is turned off in the reverse direction, and leakage current still flows. Large leakage currents can cause significant losses to the circuit, particularly in high voltage applications. Therefore, how to reduce the leakage current in the circuit is a problem to be solved.

Disclosure of Invention

In view of the above, embodiments of the present application provide a low leakage switch and a chip, which can reduce leakage current in a circuit.

In a first aspect, embodiments of the present application provide a low leakage switch including a transistor and a voltage control module. The drain electrode of the transistor is electrically connected with the input end of the voltage control module and the output end of the low-leakage switch, the source electrode of the transistor is electrically connected with the first output end of the voltage control module and the input end of the low-leakage switch, and the grid electrode of the transistor is electrically connected with the second output end of the voltage control module.

The voltage control module is used for controlling the grid voltage and the source voltage of the transistor so as to reduce the drain current of the transistor.

In one possible implementation, the voltage control module is configured to control a gate-source voltage of the transistor to control an impedance of the transistor.

In one possible implementation, the voltage control module is configured to control a source-drain voltage of the transistor to control a degree of turn-off of the transistor.

In one possible implementation manner, the voltage control module is configured to control the transistor to be turned on when a voltage between an input terminal and an output terminal of the low leakage switch is greater than or equal to a preset threshold.

In one possible implementation, the voltage control module includes a first control unit, an input terminal of the first control unit is electrically connected to a drain electrode of the transistor, and an output terminal of the first control unit is electrically connected to a gate electrode of the transistor. The first control unit is used for controlling the grid voltage of the transistor to be larger than the drain voltage of the transistor.

In one possible implementation, the voltage control module includes a second control unit, an input terminal of the second control unit is electrically connected to a source of the transistor, and an output terminal of the second control unit is electrically connected to a drain of the transistor. The second control unit is used for controlling the source voltage of the transistor to be larger than the drain voltage of the transistor.

In one possible implementation, the low leakage switch further comprises a capacitor; the first electrode plate of the capacitor is electrically connected with the drain electrode of the transistor, and the second electrode plate of the capacitor is electrically connected with the grid electrode of the transistor.

In one possible implementation, the low leakage switch further comprises a resistor; the first end of the resistor is electrically connected with the grid electrode of the transistor, and the second end of the resistor is electrically connected with the source electrode of the transistor.

In a second aspect, embodiments of the present application provide a chip comprising the low leakage switch of any one of the first aspects.

In one possible implementation, the chip further includes an ESD protection circuit, the low leakage switch being in series with the ESD protection circuit.

According to the low-leakage switch and the low-leakage chip, the voltage control module is arranged on the basis of the transistor, and the grid voltage and the source voltage of the transistor are controlled through the voltage control module, so that the impedance of the transistor is increased, and the drain current of the transistor is reduced. In addition, the impedance of the transistor is changed through the voltage control module, so that leakage current can be reduced under the condition that the starting voltage of the transistor is not changed, the requirement on the model of the transistor is avoided, and the application range is wide.

The foregoing description is only an overview of the technical solutions of the embodiments of the present application, and may be implemented according to the content of the specification, so that the technical means of the embodiments of the present application can be more clearly understood, and the following detailed description of the present application will be presented in order to make the foregoing and other objects, features and advantages of the embodiments of the present application more understandable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a low leakage switch according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of another low leakage switch according to an embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a chip according to an embodiment of the present application.

Fig. 5 is a schematic structural diagram of another chip according to an embodiment of the present application.

Reference numerals:

100. a low leakage switch; m, a transistor; D. a drain electrode; s, a source electrode; G. a gate;

110. a voltage control module;

111. a first control unit; 112. a second control unit;

C. a capacitor; r, resistance;

210. an ESD protection circuit.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the applications herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the drawings are intended to cover a non-exclusive inclusion.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: there are three cases, a, B, a and B simultaneously. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

Furthermore, the terms first, second and the like in the description and in the claims of the present application or in the above-described figures, are used for distinguishing between different objects and not for describing a particular sequential order, and may be used to expressly or implicitly include one or more such features.

In the description of the present application, unless otherwise indicated, the meaning of "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two).

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, e.g., the terms "connected" or "coupled" of a mechanical structure may refer to a physical connection, e.g., the physical connection may be a fixed connection, e.g., by a fastener, such as a screw, bolt, or other fastener; the physical connection may also be a detachable connection, such as a snap-fit or snap-fit connection; the physical connection may also be an integral connection, such as a welded, glued or integrally formed connection. "connected" or "connected" of circuit structures may refer to physical connection, electrical connection or signal connection, for example, direct connection, i.e. physical connection, or indirect connection through at least one element in the middle, so long as circuit communication is achieved, or internal communication between two elements; signal connection may refer to signal connection through a medium such as radio waves, in addition to signal connection through a circuit. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

With the use of electrical appliances in life, static electricity is also a common phenomenon. In general, static electricity is usually generated by human beings, and may be accumulated in human bodies, instruments or equipment, even components and parts themselves during the processes of production, assembly, testing, storage, handling and the like.

Electrostatic discharge is a major contributor to excessive electrical stress failure by electronic components or integrated circuit systems. The instantaneous voltage of static electricity is usually very high (> several kilovolts), and the damage of static discharge to components is destructive and permanent, which can cause the integrated circuit to burn out directly. Thus, prevention of electrostatic damage is a first challenge in the design and manufacture of all integrated circuits. When one unknowingly touches these charged objects, a discharge path is formed, momentarily damaging the electronic component or integrated circuit from the electrostatic discharge.

The current solution to the electrostatic discharge phenomenon is to provide hardware protection to the circuit when manufacturing the device. The principle of the ESD diode is that the ESD electrostatic protection diode is connected in parallel in the circuit, when the circuit works normally, the diode is in a cut-off state (high-resistance state) and does not influence the normal work of the circuit, when the circuit has abnormal overvoltage and reaches the breakdown voltage, the circuit changes from the high-resistance state to the low-resistance state rapidly, a low-resistance conduction path is provided for instant current, and meanwhile, the abnormal high voltage is clamped within a safe level, so that the protected integrated circuit or the circuit is protected. When the abnormal overvoltage disappears, the diode is restored to a high-resistance state, and the circuit works normally.

But the diode is not perfectly turned off when it is turned off in the reverse direction. The internal structure of the semiconductor material is that the reverse electric field generated by applying reverse voltage to the PN junction barrier region is larger than the electric field formed by diffusing charges in the barrier region, so that the reverse leakage current passing through the PN junction exists. The thickness of the barrier region, and the magnitude of the applied reverse voltage, together determine the magnitude of the leakage current. When subjected to back pressure, some slight current will leak from the cathode to the anode, which is usually small, but the higher the back pressure, the greater the leakage current, and the leakage current will increase with increasing temperature. Large leakage currents can cause large losses, especially in high voltage applications. Therefore, how to reduce the leakage current in the circuit is a problem to be solved.

In order to better understand the technical solutions of the present application, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings. It should be noted that, in the case of no conflict, different technical features may be combined with each other.

Fig. 1 is a schematic diagram of an application scenario provided in the embodiment of the present application, as shown in fig. 1, an input end of a low leakage switch 100 is used for receiving an electrostatic current, and an output end of the low leakage switch 100 is connected with a PAD. Or the output of the low leakage switch 100 is grounded.

Specifically, no current passes when low leakage switch 100 is off. However, in practical applications, since the PN junction exists inside the low-leakage switch 100, the low-leakage switch 100 is reverse biased during operation, and a reverse biased leakage current occurs in the low-leakage switch 100. That is, even if the low leakage switch 100 does not form a conductive channel, leakage occurs due to the existing reverse saturation current.

In this embodiment, the scenario shown in fig. 1 is taken as an example, and the low leakage switch 100 is described as an example.

Fig. 2 is a schematic structural diagram of a low leakage switch according to an embodiment of the present application, and as shown in fig. 2, the low leakage switch 100 includes a transistor M and a voltage control module 110. The drain D of the transistor M is electrically connected to the input terminal of the voltage control module 110 and the output terminal of the low leakage switch 100, the source S of the transistor M is electrically connected to the first output terminal of the voltage control module 110 and the input terminal of the low leakage switch 100, and the gate G of the transistor M is electrically connected to the second output terminal of the voltage control module 110.

The voltage control module 110 is used for controlling the gate voltage V of the transistor M _G And the source voltage V of transistor M _S To reduce the drain current I of the transistor M _D 。

The transistor M is a P-type MOS transistor, which is a switching element turned on by voltage control. The turn-on voltage of the transistor M is also called threshold voltage V _th Refers to the source-drain voltage V of the transistor M _DS At a certain value, the transistor M starts to have drain current I _D Gate-source voltage V of (2) _GS Is a value of (2). The conduction principle of the transistor M can be briefly summarized as: gate-source voltage V of transistor M _GS Greater than threshold voltage V _th After that, i.e. V _GS ≥V _th A conductive channel is formed between the source S and the drain D of the transistor M, and electrons of the substrate pass through the conductive channel to form a drain current I of the transistor M _D . Wherein the gate-source voltage V of the transistor M _GS The larger the drain current I _D The larger. Threshold voltage V of different types of transistors M _th Different, it is generally 3 to 5 volts.

Ideally, no current passes when transistor M is off. In practice, however, the reverse biased leakage current occurs in the transistor M due to the reverse bias of the PN junction between the source S of the transistor M and the substrate, and the PN junction between the drain D and the substrate during operation of the transistor M. That is, even if the transistor M does not form a conductive channel, leakage occurs due to the reverse saturation current existing between the drain D and the source S.

Specifically, as shown in fig. 2, the input terminal of the voltage control module 110 is electrically connected to the drain D of the transistor M, so as to receive the drain voltage V of the transistor M _D . The voltage control module 110 can control the drain voltage V of the transistor M according to different conversion coefficients _D And converting to obtain first output voltages and second output voltages with different magnitudes. Then, the first output voltage is transmitted to the source S of the transistor M through the first output terminal to make the source voltage V of the transistor M _S Increasing to the first output voltage. Transmitting a second output voltage to the gate G of the transistor M via the second output terminal to make the gate voltage V of the transistor M _G Increasing to the second output voltage. Thus, the voltage control module 110 can control the drain voltage V of the transistor M _D Processing to obtain gate voltage V of transistor M _G And the source voltage V of transistor M _S 。

For example, the drain voltage V of the transistor M _D At 0 volts, the voltage control module 110 inputs a drain voltage V of 0 volts _D A voltage converted to 1V is input to the gate G of the transistor M to make the gate voltage V of the transistor M _G 1V, while the drain voltage V is 0V _D Converted to 20 mV source voltage V _S The source voltage V of the transistor M _S 20 millivolts.

By voltage control module 110 by voltage V to drain _D Different treatments can be performed on the gate voltage V of the transistor M _G And source voltage V _S Control is performed such that the gate voltage V of the transistor M _G Greater than the source voltage V _S I.e. the voltage control module 110 can control the gate-source voltage V of the transistor M _GS . So that the impedance of the transistor M can be increased and the drain current I of the transistor M can be reduced under the condition of a certain closing degree _D I.e. reducing leakage currents. In addition, the impedance of the transistor M is changed by the voltage control module 110, and the transistor can be unchangedM self threshold voltage V _th In the case of (2), the leakage current is reduced, that is, transistors of different types are not required to be replaced as the transistor M, so that the limitation and the use requirement on the transistor M are reduced, and the application range of the transistors of the unified type specification is wider.

In particular, the degree of turn-off may be positively correlated to the voltage difference required by the transistor M from turn-off to turn-on. That is, the voltage control module 110 controls the source-drain voltage V of the transistor M _DS The larger the difference between the on voltage and the transistor M, the tighter the turn-off, and the smaller the leakage current. When the source-drain voltage V of the transistor M _DS After being larger than the turn-off level, the transistor M is turned on, and the current passes through the transistor M.

The voltage control module 110 controls the source voltage V of the transistor M _S The source-drain voltage V of the transistor M can be controlled _DS And further, the closing degree of the transistor M is controlled, so that the closing degree of the transistor M is set according to the requirement of discharging static current, and the transistor M can meet different static current discharging requirements.

In the embodiment of the present application, the transistor M is exemplified by a P-type transistor. The transistor M may also be an N-type transistor, and when the transistor M is an N-type transistor, the scheme changes accordingly with the properties and properties of the N-type transistor. For example, when the transistor M is an N transistor, V _GS Greater than a threshold voltage V _th Conducting later; when the transistor M is a P transistor, V _GS Less than a negative threshold voltage V _th And then conducting.

According to the low-leakage switch 100 provided by the embodiment of the application, the voltage control module 110 is arranged on the basis of the transistor M, and the grid voltage and the source voltage of the transistor M are controlled through the voltage control module 110, so that the impedance of the transistor M is increased, and the drain current of the transistor M is reduced. In addition, by changing the impedance of the transistor M through the voltage control module 110, the leakage current can be reduced without changing the turn-on voltage of the transistor M, and the use limit of the transistor M can be reduced, so that the application range of the transistors M of the same model is wider.

Optionally, the voltage control module 110 is configured to control the transistor M to be turned on when the voltage between the input terminal and the output terminal of the low leakage switch 100 is greater than or equal to a preset threshold.

Specifically, the preset threshold may be determined according to the blocking resistance of the low leakage switch 1 and the magnitude of the electrostatic current that needs to be discharged. When the voltage between the input terminal and the output terminal of the low leakage switch 100 is greater than or equal to the preset threshold, it indicates that the electrostatic current flowing into the low leakage switch 100 is greater. For example, the preset threshold may be 600 mV, and the voltage control module 110 controls the source voltage V _S 1V, control gate voltage V _G 20 mV gate-source voltage V of transistor M _GS 980 millivolts, i.e. greater than a preset threshold.

At this time, the control transistor M is turned on, and the transistor M can guide the static current to flow in from the input terminal of the low leakage switch 100 and flow out from the output terminal of the low leakage switch 100, so as to prevent the static current from accumulating in the circuit to cause damage. In addition, the resistance of the transistor M becomes low when the transistor M is turned on, and the transistor M can quickly discharge a larger static current from the output end of the low leakage switch 100 to the outside of the circuit, so that the static current is prevented from flowing into the chip to damage the circuit.

In this embodiment, when the voltage between the input end and the output end of the low leakage switch 100 is greater than or equal to the preset threshold value, the voltage control module 110 controls the transistor M to be turned on, so that the transistor M is turned on when the voltage of the electrostatic current is greater, and the electrostatic current is led to flow out of the circuit from the output end of the low leakage switch 100. In addition, in the on state, the resistance of the transistor M is reduced, so that the static current can be rapidly discharged from the output terminal of the low leakage switch 100 to the outside of the circuit, and the static current is prevented from flowing into the chip to damage the circuit.

Optionally, fig. 3 is a schematic structural diagram of another low leakage switch according to an embodiment of the present application. Fig. 3 is a schematic diagram of the embodiment shown in fig. 2, where the voltage control module 110 may include a first control unit 111, an input terminal of the first control unit 111 is electrically connected to the drain D of the transistor M, and an output terminal of the first control unit 111 is electrically connected to the gate G of the transistor M.

The first control unit 111 is used for controlling the gate electricity of the transistor MPressure V _G Greater than the drain voltage V of transistor M _D 。

Specifically, the input terminal of the first control unit 111 is electrically connected to the drain D of the transistor M for receiving the drain voltage V of the transistor M _D . The first control unit 111 may also receive the drain voltage V of the transistor M _D Processing to obtain gate voltage V of transistor M _G . The drain D and the gate G of the transistor M are electrically connected by a single first control unit 111 for the gate voltage V of the transistor M _G One-to-one control is carried out, and the control is not influenced by other circuits, so that the control is simple and effective.

The first control unit 111 may be a control loop, which is always dependent on the drain voltage V _D Control gate voltage V _G To make the gate voltage V _G And drain voltage V _D A stable difference is maintained. For example, the first control unit 111 may include an operational amplifier circuit. The input end of the operational amplifier circuit is electrically connected with the drain electrode D of the transistor M, and the output end of the operational amplifier circuit is electrically connected with the grid electrode G of the transistor M. Drain voltage V of operational amplifier circuit to transistor M _D Amplifying to obtain gate voltage V of transistor M _G . For example, the drain voltage is 0V, and the operational amplifier circuit amplifies the 0V voltage to 1V voltage to obtain the gate voltage V _G 。

Optionally, as shown in fig. 3, the voltage control module 110 further includes a second control unit 112, an input terminal of the second control unit 112 is electrically connected to the source S of the transistor M, and an output terminal of the second control unit 112 is electrically connected to the drain D of the transistor M.

The second control unit 112 is used for controlling the source voltage V of the transistor M _S Greater than the drain voltage V of transistor M _D 。

Specifically, the input terminal of the second control unit 112 is electrically connected to the drain D of the transistor M for receiving the drain voltage V of the transistor M _D . The second control unit 112 can also receive the drain voltage V of the transistor M _D Processing to obtain source voltage V of transistor M _S . The drain D and the source S of the transistor M are electrically connected by a separate second control unit 112 for the transistor MSource voltage V of (2) _S One-to-one control is carried out, and the control is not influenced by other circuits, so that the control is simple and effective.

The second control unit 112 is similar to the first control unit 111 in structure and principle, and the second control unit 112 may be another control loop, which is always based on the drain voltage V _D Controlling the source voltage V _S To make the source voltage V _S And drain voltage V _D A stable difference is maintained. For example, the second control unit 112 may include an operational amplifier circuit. The input end of the operational amplifier circuit is electrically connected with the drain electrode D of the transistor M, and the output end of the operational amplifier circuit is electrically connected with the source electrode S of the transistor M. Drain voltage V of operational amplifier circuit to transistor M _D Amplifying to obtain source voltage V of transistor M _S . For example, drain voltage V _D The operational amplifier circuit amplifies the 0V voltage to 20 mV voltage to obtain a source voltage V _S 。

Optionally, the low leakage switch 100 provided in the embodiment of the present application may further include a capacitor C, where a first plate of the capacitor C is electrically connected to the drain D of the transistor M, and a second plate of the capacitor C is electrically connected to the gate G of the transistor M.

Specifically, the effect of stabilizing voltage can be realized by virtue of the charge-discharge characteristic of the capacitor, and the effect of protecting the grid electrode G of the transistor M can be also realized during electrostatic discharge and voltage surge. When the circuit works normally, the output end of the low leakage switch 100 has stable voltage, the capacitor C is connected with the low leakage switch 100 and the grid electrode G of the transistor M, and the grid electrode voltage V of the transistor M can be further maintained by utilizing the self charge-discharge characteristic on the basis of the stable voltage of the output end of the low leakage switch 100 _G And (3) stability.

Optionally, the low leakage switch 100 provided in the embodiment of the present application may further include a resistor R, where a first end of the resistor R is electrically connected to the gate G of the transistor M, and a second end of the resistor R is electrically connected to the source S of the transistor M.

Specifically, the resistor R controls the gate voltage V of the transistor M by voltage division _G The breakdown voltage of the transistor M is reduced, so that the transistor M can be recovered after being broken down, and the grid G of the transistor M are preventedThe source S is shorted, or the gate G and drain D of the transistor M are shorted.

Embodiments of the present application also provide a chip comprising a low leakage switch 100 as in any of the above embodiments.

Fig. 4 is a schematic structural diagram of a chip according to an embodiment of the present application. As shown in fig. 4, the chip includes a low leakage switch 100.

The chip provided in this embodiment of the present application includes the low leakage switch 100 provided in any one of the embodiments described above, and has the same functional modules and beneficial effects as the low leakage switch 100, and will not be described herein again.

Optionally, fig. 5 is a schematic structural diagram of another chip provided in the embodiment of the present application, and fig. 5 is a schematic structural diagram of the embodiment shown in fig. 4, where the chip further includes an ESD protection circuit 210, and the low leakage switch 100 is connected in series with the ESD protection circuit 210.

Illustratively, the low leakage switch 100 is connected in series with the ESD protection circuit 210. It is understood that the output terminal of the ESD protection circuit 210 is electrically connected to the input terminal of the low leakage switch 100, the input terminal of the ESD protection circuit 210 is electrically connected to the power supply voltage VCC, and the output terminal of the low leakage switch 100 is electrically connected to the PAD terminal, as shown in fig. 5. Alternatively, it may be understood that the output terminal of the low leakage switch 100 is electrically connected to the input terminal of the ESD protection circuit 210, the input terminal of the low leakage switch 100 is electrically connected to the power supply voltage VCC, and the output terminal of the ESD protection circuit 210 is electrically connected to the PAD terminal.

It should be noted that fig. 5 is a schematic diagram illustrating a chip when the transistor in the low-leakage switch 100 is a P-type MOS transistor. In practical applications, if the transistor in the low leakage switch 100 is an N-type MOS transistor, the low leakage switch 100 and the ESD protection circuit 210 are connected in series between PAD and ground.

The ESD protection circuit 210 is in an off state when the protected circuit is operating normally. The ESD protection circuit 210 is usually implemented by a diode, a triode or a MOS transistor, and has a drain current I due to structural characteristics _D Therefore, the low leakage switch 100 is connected in series to the ESD protection circuit 210, and the drain current I flowing from the ESD protection circuit 210 can be prevented _D And flows out to further realize the low leakage function.

When an ESD event occurs, the ESD protection circuit 210 is turned on, and at the same time, the low leakage switch 100 is turned on, so that when the static electricity in the protected circuit is too large, the static electricity current is led out of the chip through the ESD protection circuit 210 and the low leakage switch 100, and the chip is prevented from being damaged by the static electricity, so that the chip is protected by the static electricity.

In summary, according to the low leakage switch 100 and the chip provided in the embodiments of the present application, the voltage control module 110 is provided on the basis of the transistor M, and the voltage control module 110 controls the gate voltage and the source voltage of the transistor M, so as to increase the impedance of the transistor M and reduce the drain D current of the transistor M. In addition, the voltage control module 110 changes the impedance of the transistor M, so that the leakage current can be reduced without changing the turn-on voltage of the transistor M, the requirement on the model of the transistor M is avoided, and the application range is wide.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The functional units or modules in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in part or all or part of the technical solution contributing to the prior art or in the form of a software product stored in a storage medium, including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to perform all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The application may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of first, second, third, etc. does not denote any order, and the words are to be interpreted as names. The steps in the above embodiments should not be construed as limiting the order of execution unless specifically stated.

The above embodiments are merely for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. A low leakage switch, comprising: a transistor and a voltage control module;

the drain electrode of the transistor is electrically connected with the input end of the voltage control module and the output end of the low-leakage switch, the source electrode of the transistor is electrically connected with the first output end of the voltage control module and the input end of the low-leakage switch, and the grid electrode of the transistor is electrically connected with the second output end of the voltage control module;

2. The low leakage switch of claim 1, wherein the voltage control module is configured to control a gate-source voltage of the transistor to control an impedance of the transistor.

3. The low leakage switch according to claim 1 or 2, wherein the voltage control module is configured to control a source-drain voltage of the transistor to control a degree of turn-off of the transistor.

4. A low leakage switch according to claim 3, wherein the voltage control module is configured to control the transistor to be turned on when a voltage between the input terminal and the output terminal of the low leakage switch is greater than or equal to a preset threshold.

5. The low leakage switch according to claim 1 or 2, wherein the voltage control module comprises a first control unit, an input terminal of the first control unit being electrically connected to a drain of the transistor, an output terminal of the first control unit being electrically connected to a gate of the transistor;

the first control unit is used for controlling the grid voltage of the transistor to be larger than the drain voltage of the transistor.

6. The low leakage switch of claim 5, wherein the voltage control module comprises a second control unit having an input electrically connected to the drain of the transistor and an output electrically connected to the source of the transistor;

the second control unit is configured to control the source voltage of the transistor to be greater than the drain voltage of the transistor.

7. The low leakage switch according to claim 1 or 2, further comprising a capacitor, a first plate of the capacitor being electrically connected to a drain of the transistor, a second plate of the capacitor being electrically connected to a gate of the transistor.

8. The low leakage switch according to claim 1 or 2, further comprising a resistor, a first terminal of the resistor being electrically connected to the gate of the transistor, and a second terminal of the resistor being electrically connected to the source of the transistor.

9. A chip comprising a low leakage switch according to any one of claims 1 to 8.

10. The chip of claim 9, further comprising an ESD protection circuit, the low leakage switch being in series with the ESD protection circuit.