CN109283992A

CN109283992A - A kind of bidirectional power supply protection circuit

Info

Publication number: CN109283992A
Application number: CN201710602479.XA
Authority: CN
Inventors: 汪会
Original assignee: Huawei Device Dongguan Co Ltd
Current assignee: Huawei Device Co Ltd
Priority date: 2017-07-21
Filing date: 2017-07-21
Publication date: 2019-01-29
Anticipated expiration: 2037-07-21
Also published as: CN109283992B

Abstract

The embodiment of the present application discloses a kind of bidirectional power supply protection circuit; it is related to the communications field; it solves and accessory is formerly connected to handheld device and then in the case where power supply unit is connected to handheld device again, the problem of voltage handheld device of power supply unit output interferes.The specific scheme is that bidirectional power supply protection circuit includes control module and first switch module; the first end of control module is connect with the first end of first switch module; the second end of control module is connect with the second end of first switch module; the third end of control module is connect with the third end of first switch module; the first end of first switch module is for connecting handheld device; the third end of first switch module is for connecting power supply unit; if the first end of control module detects high level, control module controls first switch module and closes.During the embodiment of the present application is powered simultaneously for dual power supply.

Description

A kind of bidirectional power supply protection circuit

Technical field

The invention relates to the communications fields more particularly to a kind of bidirectional power supply to protect circuit.

Background technique

In the prior art, it when the handheld devices such as mobile phone, tablet computer need to connect the accessories such as mouse, keyboard, needs simultaneously When connecting the power supply units such as charger, there can be the following order of connection:

By switching device, if power supply unit is first connected to handheld device, accessory is then connected to handheld device again, Then handheld device will not output voltage, powered from power supply unit to handheld device and accessory.But by switching device, if first Accessory is connected to handheld device, then handheld device meeting output voltage is powered to accessory, if being at this time again connected to power supply unit Handheld device, then the internal circuit of the voltage meeting handheld device of power supply unit output interferes, or even damage handheld device.

Summary of the invention

The embodiment of the present application provides a kind of bidirectional power supply protection circuit, solves that accessory is formerly connected to handheld device is right In the case where power supply unit is connected to handheld device again afterwards, what the voltage handheld device of power supply unit output interfered is asked Topic.

In order to achieve the above objectives, the embodiment of the present application adopts the following technical scheme that

The embodiment of the present application in a first aspect, providing a kind of bidirectional power supply protection circuit, which protects circuit can To include: control module and first switch module.Wherein, the first end of the first end of control module and first switch module connects It connects, the second end of control module is connect with the second end of first switch module, the third end of control module and first switch module The connection of third end, the first end of first switch module is for connecting handheld device, and the third end of first switch module is for connecting Connect power supply unit.If the first end of control module detects high level, control module controls first switch module and closes.And In the embodiment of the present application, the meaning for representing cut-off is closed.

Bidirectional power supply provided by the embodiments of the present application protects circuit, including control module and first switch module, if control The first end of module detects high level, then control module control first switch module is closed.In this way, formerly accessory is connected to In the case where handheld device, handheld device output voltage, the first end of control module can detect high level, control first Switch module is closed.If power supply unit is connected to handheld device again at this time, the voltage of power supply unit output can not reach hand The voltage of holding equipment, i.e. power supply unit output can not the internal circuit of handheld device interfere, realize handheld device Protection.

With reference to first aspect, in one possible implementation, if the third end of control module detects high level, Control module controls first switch module and opens.In this way, power supply is set in the case where power supply unit is formerly connected to handheld device Standby output voltage, the third end of control module can detect high level, be opened by control first switch module, so that for Electric equipment can power to handheld device.In the embodiment of the present application, the meaning for representing conducting is opened.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, control module can To include: homophase input branch, anti-phase input branch, feedback branch, operational amplifier, the first transistor and first resistor.Its In, the first end of homophase input branch connects to power supply, the second end of homophase input branch and the homophase input of operational amplifier End connection, the third end ground connection of homophase input branch；The second end of anti-phase input branch and the inverting input terminal of operational amplifier Connection, the third end ground connection of anti-phase input branch；The first end of feedback branch and the non-inverting input terminal of operational amplifier connect, instead The output end of the second end and operational amplifier of presenting branch connects；The positive power source terminal of operational amplifier connects to power supply, and operation is put The negative power end ground connection of big device；The grid of the first transistor and the output end of operational amplifier connect, and the first of the first transistor Pole ground connection, the second level of the first transistor and the first end of first resistor connect；The first end of anti-phase input branch is control mould The first end of block, the second level of the first transistor are the second end of control module, and the second end of first resistor is control module Third end.If the first end of control module detects high level, by the second end input operational amplifier of anti-phase input branch Inverting input terminal voltage be higher than by homophase input branch second end input operational amplifier non-inverting input terminal voltage, The output end of operational amplifier exports low level, the first transistor cut-off, thus the first transistor and first resistor control first Switch module is closed；Feedback branch is for making the voltage of the inverting input terminal of operational amplifier persistently be higher than the same of operational amplifier The voltage of phase input terminal.If the third end of control module detects high level, fortune is inputted by the second end of anti-phase input branch The voltage for calculating the inverting input terminal of amplifier is lower than by the homophase input of the second end input operational amplifier of homophase input branch The voltage at end, the output end of operational amplifier export high level, and the first transistor conducting is opened to control first switch module It opens；The non-inverting input terminal that feedback branch is used to that the voltage of the inverting input terminal of operational amplifier to be made to be consistently less than operational amplifier Voltage.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, anti-phase input branch Road may include: second resistance and 3rd resistor.The second end of second resistance and the first end of 3rd resistor connect；Second resistance First end be anti-phase input branch first end, the second end of second resistance is the second end of reversed input branch, third electricity The second end of resistance is the third end of reversed input branch.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, homophase input branch Road may include: the 4th resistance, the 5th resistance and capacitor.The second end of 4th resistance is connect with the first end of the 5th resistance, also It is connect with the first end of capacitor, the second end of capacitor is connect with the second end of the 5th resistance；The first end of 4th resistance is same phase The first end of branch is inputted, the second end of the 4th resistance is the second end of homophase input branch, and the second end of the 5th resistance is same Mutually input the third end of branch.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, feedback branch can To include: the 6th resistance.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, first switch mould Block may include: second transistor.The first end of the extremely first switch module of the first of second transistor, the grid of second transistor The extremely second end of first switch module, the third end of the extremely first switch module of the second of second transistor.If control module First end detect high level, then control module control second transistor cut-off.If the third end of control module detects height Level, then control module control second transistor conducting.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, in order to solve hand The problem of voltage of holding equipment output interferes power supply unit, it can also include: the 7th resistance that bidirectional power supply, which protects circuit, And it is set to the second switch module between first switch module and power supply unit.The first end of second switch module and first The third end of switch module connects, and the second end of second switch module is connect with the second end of first switch module, second switch The third end of module is for connecting power supply unit；The first end of 7th resistance is connect with the first end of second switch module, and the 7th The second end of resistance is connect with the second end of second switch module.If the first end of control module detects high level, control Module controls first switch module and second switch module is closed.If the third end of control module detects high level, control Module controls first switch module and second switch module is opened.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, second switch mould Block may include: third transistor.The first end of the extremely second switch module of the first of third transistor, the grid of third transistor The extremely second end of second switch module, the third end of the extremely second switch module of the second of third transistor.If control module First end detect high level, then control module control second transistor and third transistor cut-off.If the of control module Three ends detect high level, then control module control second transistor and third transistor conducting.

With reference to first aspect with above-mentioned possible implementation, in alternatively possible implementation, the first transistor For N-type field-effect tube, second transistor and third transistor are p-type field-effect tube.

The second aspect of the embodiment of the present application, provides a kind of bidirectional power supply protection circuit, which protects circuit can To include: control module and first switch module.The first end of control module controls signal for receiving, and the second of control module End is connect with the second end of first switch module, and the third end of control module is connect with the third end of first switch module, and first The first end of switch module is for connecting handheld device, and the third end of first switch module is for connecting power supply unit.Work as control Signal by the first level conversion be second electrical level when, control module control first switch module close.

Bidirectional power supply provided by the embodiments of the present application protects circuit, including control module and first switch module, works as control Signal by the first level conversion be second electrical level when, control module control first switch module close.In this way, formerly accessory is connected In the case where being connected to handheld device, handheld device output voltage, and controlling control signal by the first level conversion is second electrical level, When controlling signal by the first level conversion is second electrical level, control module controls first switch module and closes.If again will at this time Power supply unit is connected to handheld device, then the voltage of power supply unit output can not reach handheld device, i.e. power supply unit exports Voltage can not the internal circuit of handheld device interfere, realize the protection of handheld device.

In conjunction with second aspect, in one possible implementation, when controlling signal is the first level, control module control First switch module processed is opened.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, control module can To include: the first transistor and first resistor.First pole of the first transistor is grounded, the second level of the first transistor and the first electricity The first end of resistance connects；The grid of the first transistor is the first end of control module, and the second of the first transistor extremely controls mould The second end of block, the second end of first resistor are the third end of control module.When control signal is second by the first level conversion When level, the first transistor cut-off, so that the first transistor and first resistor control first switch module are closed.When control signal When for the first level, the first transistor conducting, to control the unlatching of first switch module.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, in order to first When the grid of transistor does not receive control signal, so that the grid of the first transistor has determining level, so that two-way guarantor Protection circuit is stablized, and control module can also include: second resistance.The first end of second resistance and the grid of the first transistor connect It connects, the second end of second resistance and the first pole of the first transistor connect.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, control module can To include: input port and 3rd resistor.The connection of the first end of input port and 3rd resistor；Input port is control module First end, the first end of 3rd resistor are the second end of control module, and the second end of 3rd resistor is the third end of control module.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, first switch mould Block may include: second transistor.The first end of the extremely first switch module of the first of second transistor, the grid of second transistor The extremely second end of first switch module, the third end of the extremely first switch module of the second of second transistor.When control signal By the first level conversion be second electrical level when, control module control second transistor cut-off.When controlling signal is the first level, Control module controls second transistor conducting.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, in order to solve hand The problem of voltage of holding equipment output interferes power supply unit, it can also include: the 4th resistance that bidirectional power supply, which protects circuit, And it is set to the second switch module between first switch module and power supply unit.The first end of second switch module and first The third end of switch module connects, and the second end of second switch module is connect with the second end of first switch module, second switch The third end of module is for connecting power supply unit；The first end of 4th resistance is connect with the first end of second switch module, and the 4th The second end of resistance is connect with the second end of second switch module.When controlling signal by the first level conversion is second electrical level, Control module controls first switch module and second switch module is closed.When control signal is the first level, control module control First switch module and second switch module are opened.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, second switch mould Block may include: third transistor.The first end of the extremely second switch module of the first of third transistor, the grid of third transistor The extremely second end of second switch module, the third end of the extremely second switch module of the second of third transistor.When control signal By the first level conversion be second electrical level when, control module control second transistor and third transistor cut-off.When control signal When for the first level, control module controls second transistor and third transistor conducting.

In conjunction with second aspect and above-mentioned possible implementation, in alternatively possible implementation, the first transistor For N-type field-effect tube, second transistor and third transistor are p-type field-effect tube.

The third aspect of the embodiment of the present application, provides a kind of bidirectional power supply protection circuit, which protects circuit packet It includes: input port and first switch module.Input port also connects with the second end of first switch module for receiving control signal It connects, the first end of first switch module is for connecting handheld device, and the third end of first switch module is for connecting power supply unit. When controlling signal by low transition is high level, first switch module is closed.

Bidirectional power supply provided by the embodiments of the present application protects circuit, including input port and first switch module, works as control Signal by low transition be high level when, first switch module close.In this way, accessory to be formerly connected to the feelings of handheld device Under condition, handheld device output voltage, and controlling control signal by low transition is high level, when control signal is turned by low level When being changed to high level, first switch module is closed.If power supply unit is connected to handheld device, power supply unit output again at this time Voltage can not reach handheld device, i.e., the voltage of power supply unit output can not the internal circuit of handheld device interfere, Realize the protection of handheld device.

In conjunction with the third aspect, in one possible implementation, when controlling signal is low level, first switch module It opens.

The fourth aspect of the embodiment of the present application provides a kind of handheld device, which includes: such as first aspect or Bidirectional power supply in the possible implementation of one side protects circuit, alternatively, such as second aspect or second aspect is possible Bidirectional power supply in implementation protects circuit, alternatively, as double in the possible implementation of the third aspect or the third aspect To power supply protection circuit.

5th aspect of the embodiment of the present application, provides a kind of switching device, which includes: such as first aspect or the Bidirectional power supply in the possible implementation of one side protects circuit, alternatively, such as second aspect or second aspect is possible Bidirectional power supply in implementation protects circuit, alternatively, as double in the possible implementation of the third aspect or the third aspect To power supply protection circuit.

6th aspect of the embodiment of the present application, provides a kind of possible realization applied to such as first aspect or first aspect Bidirectional power supply described in mode protects the control method of circuit, this method comprises: if the first end of control module detects high electricity It is flat, then first switch module is controlled by control module and closed.

In conjunction with the 6th aspect, in one possible implementation, if the third end of control module detects high level, First switch module is controlled by control module to open.

7th aspect of the embodiment of the present application, provides a kind of possible realization applied to such as second aspect or second aspect Bidirectional power supply described in mode protects the control method of circuit, this method comprises: the control that the first end for working as control module receives Signal processed by the first level conversion be second electrical level when, pass through control module control first switch module close.

In conjunction with the 7th aspect, in one possible implementation, when the control letter that the first end of control module receives Number be the first level when, pass through control module control first switch module open.

Detailed description of the invention

Fig. 1 is that a kind of bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 2 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 3 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 4 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 5 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 5 A is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 6 is a kind of equivalent circuit provided by the embodiments of the present application；

Fig. 7 is another equivalent circuit provided by the embodiments of the present application；

Fig. 8 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 8 A is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Fig. 9 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 10 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 11 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 12 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 13 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 14 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 14 A is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 15 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 15 A is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 16 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 16 A is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 17 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 17 A is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 18 is that another bidirectional power supply provided by the embodiments of the present application protects circuit；

Figure 19 is a kind of handheld device provided by the embodiments of the present application；

Figure 20 is a kind of switching device provided by the embodiments of the present application；

Figure 21 is a kind of control method that circuit is protected applied to bidirectional power supply provided by the embodiments of the present application；

Figure 22 is another control method for being applied to bidirectional power supply and protecting circuit provided by the embodiments of the present application.

Specific embodiment

It should be noted that all transistors used in the examples of the application all can be thin film transistor (TFT) or field-effect Pipe or the identical device of other characteristics, since the source electrode of the transistor used here, drain electrode are symmetrically, so its source electrode, leakage Pole can be interchanged.In the embodiment of the present application, to distinguish the two poles of the earth of transistor in addition to grid, wherein source will be known as in a pole Pole, another pole are known as draining.In addition, transistor can be divided into N-type transistor or P-type crystal by the characteristic differentiation according to transistor Pipe.

Fig. 1 is that a kind of bidirectional power supply provided by the embodiments of the present application protects circuit.As shown in Figure 1, the bidirectional power supply is protected Circuit may include；Control module 101 and first switch module 102.

Wherein, the first end of control module 101 is connect with the first end of first switch module 102, and the of control module 101 Two ends are connect with the second end of first switch module 102, the third end of control module 101 and the third of first switch module 102 End connection.The first end of first switch module 102 is for connecting handheld device, and the third end of first switch module 102 is for connecting Connect power supply unit.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, control module 101 first end can detecte high level, close at this point, control module 101 controls first switch module 102.At this point, if again Power supply unit is connected to handheld device, then the voltage of power supply unit output can not interfere the internal circuit of handheld device, thus Realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage, the of control module 101 Three ends can detecte high level, open at this point, control module 101 controls first switch module 102, so that power supply unit is to hand Holding equipment power supply.

In the embodiment of the present application, further, as shown in Fig. 2, control module 101 may include；Homophase input branch 1011, anti-phase input branch 1012, feedback branch 1013, operational amplifier 1014, the first transistor 1015 and first resistor 1016.In Fig. 2 with first resistor 1016 be R1 be exemplify.

Wherein, the first end of homophase input branch 1011 connects to power supply, the second end and fortune of homophase input branch 1011 Calculate the non-inverting input terminal connection of amplifier 1014, the third end ground connection of homophase input branch；The second of anti-phase input branch 1012 End is connect with the inverting input terminal of operational amplifier 1014, the third end ground connection of anti-phase input branch 1012；Feedback branch 1013 First end connect with the non-inverting input terminal of operational amplifier 1014, the second end of feedback branch 1013 and operational amplifier 1014 Output end connection；The positive power source terminal of operational amplifier 1014 connects to power supply, the negative power end ground connection of operational amplifier 1014； The grid of the first transistor 1015 is connect with the output end of operational amplifier 1014, the first pole ground connection of the first transistor 1015, Second pole of the first transistor 1015 is connect with the first end of resistance R1.

The first end of anti-phase input branch 1012 is the first end of control module 101, the second pole of the first transistor 1015 For the second end of control module 101, the second end of resistance R1 is the third end of control module 101.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, anti-phase input The first end of branch 1012 can detecte high level.At this point, inputting operation amplifier by the second end of anti-phase input branch 1012 The voltage of the inverting input terminal of device 1014 is higher than by the same of the second end input operational amplifier 1014 of homophase input branch 1011 The voltage of phase input terminal, the output end of operational amplifier 1014 export low level, and the first transistor 1015 ends, so that first is brilliant Body pipe 1015 and resistance R1 control first switch module 102 are closed.At this point, if power supply unit is connected to handheld device again, The voltage of power supply unit output can not interfere the internal circuit of handheld device, to realize the protection of handheld device.And it is anti- The same phase that feedback branch 1013 is used to that the voltage of the inverting input terminal of operational amplifier 1014 to be made persistently to be higher than operational amplifier 1014 The voltage of input terminal.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, The second end of resistance R1 can detecte high level, at this point, since high electricity is not detected in the first end of anti-phase input branch 1012 It is flat, therefore, by the voltage of the inverting input terminal of the second end input operational amplifier 1014 of anti-phase input branch 1012 be lower than by The voltage of the non-inverting input terminal of the second end input operational amplifier 1014 of homophase input branch 1011, the output of operational amplifier End output high level, the first transistor 1015 are connected, so that the unlatching of first switch module 102 is controlled, so that power supply unit can be with It powers to handheld device.Feedback branch 1013 is for making the voltage of the inverting input terminal of operational amplifier 1014 be consistently less than operation The voltage of the non-inverting input terminal of amplifier 1014.

In the embodiment of the present application, further, as shown in figure 3, anti-phase input branch 1012 may include: second resistance And 3rd resistor.With second resistance it is R2 in Fig. 3, be R3 with 3rd resistor is to exemplify.

Wherein, the second end of resistance R2 is connect with the first end of resistance R3.The first end of resistance R2 is anti-phase input branch 1012 first end, the second end of resistance R2 are the second end of reversed input branch 1012, and the second end of resistance R3 is reversed defeated Enter the third end of branch 1012.

In the embodiment of the present application, further, as shown in figure 3, homophase input branch 1011 may include: the 4th electricity Resistance, the 5th resistance and capacitor.With the 4th resistance for R4 in Fig. 3, the 5th resistance is R5, and capacitor is that C is to exemplify.

Wherein, the second end of resistance R4 is connect with the first end of resistance R5, is also connect with the first end of capacitor C, capacitor C's Second end is connect with the second end of resistance R5.The first end of resistance R4 is the first end of homophase input branch 1011, resistance R4's Second end is the second end of homophase input branch 1011, and the second end of resistance R5 is the third end of homophase input branch 1011.

In the embodiment of the present application, further, as shown in figure 3, feedback branch 1013 may include the 6th resistance.Scheming In 3 with the 6th resistance be R6 be exemplify.

In the embodiment of the present application, further, as shown in figure 4, first switch module 102 may include the second crystal Pipe.

Wherein, the first end of the extremely first switch module 102 of the first of second transistor, the grid of second transistor are the The second end of one switch module 102, the third end of the extremely first switch module 102 of the second of second transistor.

It should be noted that in the embodiment of the present application, the specific structure of the control module 101 in Fig. 4 in Fig. 3 to control The specific structure of module 101 is to exemplify, and the specific structure of control module 101 can also be referring to fig. 1 and fig. 2 in Fig. 4 Control module 101 specific structure, details are not described herein for the embodiment of the present application.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, resistance R2's First end can detecte high level, and the second end of resistance R2 generates voltage, i.e. the inverting input terminal of operational amplifier 1014 produces Raw voltage, since the voltage of capacitor C cannot be mutated, the non-inverting input terminal of operational amplifier 1014, which generates voltage, to be later than Inverting input terminal generates voltage, so that the output end of operational amplifier 1014 exports low level.The first transistor 1015 ends, from And the first transistor 1015 and resistance R1 control second transistor cut-off.At this point, if power supply unit is connected to handheld device again, Then the voltage of power supply unit output can not interfere the internal circuit of handheld device, to realize the protection of handheld device.And The homophase input that resistance R6 is used to that the voltage of the inverting input terminal of operational amplifier 1014 to be made persistently to be higher than operational amplifier 1014 The voltage at end.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, Since the body diode of third transistor is connected, so that the second end of resistance R1 detects high level.At this point, handheld device will not Output voltage, the voltage of the second end of resistance R2 are 0V, i.e., the voltage of the inverting input terminal of operational amplifier 1014 is 0V.Due to The second end of resistance R4 generates voltage, i.e. the non-inverting input terminal of operational amplifier 1014 generates voltage, is greater than inverting input terminal Voltage 0V, therefore operational amplifier 1014 output end export high level.The first transistor 1015 is connected, thus control second Transistor turns, so that power supply unit is powered to handheld device.Resistance R6 is used to make the inverting input terminal of operational amplifier 1014 Voltage be consistently less than operational amplifier 1014 non-inverting input terminal voltage.

In the embodiment of the present application, further, as shown in figure 5, in order to solve the voltage of handheld device output to power supply The problem of equipment interferes, it can also include: the 7th resistance 103 which, which protects circuit, and is set to first and opens Close the second switch module 104 between module 102 and power supply unit.In Fig. 5 with the 7th resistance 103 be R7 be exemplify.

Wherein, the first end of second switch module 104 is connect with the third end of first switch module 102, second switch mould The second end of block 104 is connect with the second end of first switch module 102, and the third end of second switch module 104 is supplied for connecting Electric equipment；The first end of resistance R7 is connect with the first end of second switch module 104, the second end and second switch mould of resistance R7 The second end of block 104 connects.

It should be noted that in the embodiment of the present application, the specific structure and first switch of the control module 101 in Fig. 5 The specific structure of module 102 is by taking the specific structure of control module 101 in Fig. 4 and the specific structure of first switch module 102 as an example It shows, and the specific structure of control module 101 and the specific structure of first switch module 102 can also refer to Fig. 1, Fig. 2 in Fig. 5 With the specific structure of control module 101 shown in Fig. 3, details are not described herein for the embodiment of the present application.

In the embodiment of the present application, further, as shown in Figure 5A, second switch module 104 may include third crystal Pipe.

Wherein, the first end of the extremely second switch module 104 of the first of third transistor, the grid of third transistor are the The second end of two switch modules 104, the third end of the extremely second switch module 104 of the second of third transistor.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, resistance R2's First end can detecte high level, and the second end of resistance R2 generates voltage, i.e. the inverting input terminal of operational amplifier 1014 produces Raw voltage, since the voltage of capacitor C cannot be mutated, the non-inverting input terminal of operational amplifier 1014, which generates voltage, to be later than Inverting input terminal generates voltage, so that the output end of operational amplifier 1014 exports low level.The first transistor 1015 ends, from And the first transistor 1015 and resistance R1 control second transistor cut-off, and the first transistor 1015 and resistance R7 control third are brilliant The cut-off of body pipe.At this point, the voltage of power supply unit output can not reach hand-held set if power supply unit is connected to handheld device again It is standby, while the voltage of handheld device output can not also reach power supply unit, avoid handheld device and the mutual of power supply unit does It disturbs, to realize the protection of handheld device and power supply unit.And resistance R6 is for keeping the reverse phase of operational amplifier 1014 defeated Enter end voltage be persistently higher than operational amplifier 1014 non-inverting input terminal voltage so that operational amplifier 1014 is defeated Outlet persistently exports low level.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, Since the body diode of third transistor is connected, so that the second end of resistance R1 detects high level.At this point, handheld device will not Output voltage, the voltage of the second end of resistance R2 are 0V, i.e., the voltage of the inverting input terminal of operational amplifier 1014 is 0V.Due to The second end of resistance R4 generates voltage, i.e. the non-inverting input terminal of operational amplifier 1014 generates voltage, is greater than inverting input terminal Voltage 0V, therefore operational amplifier 1014 output end export high level.The first transistor 1015 is connected, thus control second Transistor and third transistor conducting, so that power supply unit can power to handheld device.Resistance R6 is for making operational amplifier The voltage of 1014 inverting input terminal is consistently less than the voltage of the non-inverting input terminal of operational amplifier 1014, so that operation is put The output end of big device 1014 persistently exports high level.

It should be noted that since the resistance R6 voltage for exporting the output end of operational amplifier 1014 will affect same phase The voltage of input terminal input, therefore the output end of operational amplifier 1014 is after export certain level, what non-inverting input terminal inputted Corresponding change can occur for voltage.After the voltage of non-inverting input terminal changes, in order to enable operational amplifier 1014 can be held It is continuous to export the level that initially exports, resistance R2, resistance R3, resistance R4, resistance R5 and resistance R6 resistance value need to meet it is certain It is required that.

It is illustrative: after the output end of operational amplifier 1014 exports low level, since the second end of resistance R6 is Low level, the second end ground connection of resistance R5, and the first end of resistance R5 is connect with the first end of resistance R6, therefore can be equivalent to It connects after resistance R5 is in parallel with resistance R6 with resistance R4, equivalent circuit diagram is as shown in fig. 6, and with operational amplifier in Fig. 6 The voltage of 1014 non-inverting input terminal is that V+ is to exemplify.At this point, the voltage of the non-inverting input terminal of operational amplifier 1014 are as follows:

The voltage of the inverting input terminal of operational amplifier 1014 are as follows:

In order to enable the output end of operational amplifier 1014 to continue to export low level, so that second transistor and the Three transistors persistently keep ending, therefore the voltage V+ of the non-inverting input terminal of operational amplifier 1014 needs to be less than inverting input terminal Voltage V-, it may be assumed that

Calculated result are as follows:

After the output end of operational amplifier 1014 exports high level, since the second end of resistance R6 is high level, electricity The first end for hindering R4 connects power supply, and the second end of resistance R4 is connect with the first end of resistance R6, therefore can be equivalent to resistance It connects after R4 is in parallel with resistance R6 with resistance R5, equivalent circuit diagram is as shown in fig. 7, and with operational amplifier 1014 in Fig. 7 Non-inverting input terminal voltage be V+ ' be exemplify.At this point, the voltage of the non-inverting input terminal of operational amplifier 1014 are as follows:

In order to enable the output end of operational amplifier 1014 to export high level always, so that second transistor and Three transistors are held on, therefore the voltage V+ ' of the non-inverting input terminal of operational amplifier 1014 is needed greater than inverting input terminal Voltage V-, it may be assumed that

Calculated result are as follows:

Therefore, the requirement that the resistance value of resistance R2, resistance R3, resistance R4, resistance R5 and resistance R6 meet are as follows:

For the ease of the understanding of those skilled in the art, the application by following embodiment to bidirectional power supply protect circuit into Row illustrates.

In concrete implementation, for example, the homophase input branch 1011 that control module 101 includes includes resistance R4, resistance R5 and capacitor C.Anti-phase input branch 1012 includes resistance R2 and resistance R3.Feedback branch 1013 includes resistance R6.First crystal Pipe 1015 is N-type field-effect tube, and the first extremely source electrode, second extremely drains.The second transistor that first switch module 102 includes It extremely drains for p-type field-effect tube, first, the second extremely source electrode.The third transistor that second switch module 104 includes is p-type Field-effect tube, the first extremely source electrode, second extremely drains.Resistance R1 is provided between the grid and source electrode of second transistor.The Resistance R7 is provided between the grid and source electrode of three transistors.Specifically, bidirectional power supply protects circuit as shown in figure 8, in fig. 8 It is Q1 with the first transistor, second transistor Q2, third transistor is that Q3 is to exemplify.Assuming that R2=R3, R4=R5=R6, Meet the resistance value requirement of resistance R2, resistance R3, resistance R4, resistance R5 and resistance R6.

Wherein, the first end of resistance R2 is connect with the drain electrode of field-effect tube Q2, and the of the second end of resistance R2 and resistance R3 One end connection, also connect with the inverting input terminal of operational amplifier, the second end ground connection of resistance R3.The first end of resistance R4 and field The source electrode of effect pipe Q2 connects, and the second end of resistance R4 connect with the first end of resistance R5, also connect with the first end of capacitor C, It is also connect with the non-inverting input terminal of operational amplifier, the second end of resistance R5 is connect with the second end of capacitor C, is also grounded.Operation The positive power source terminal of amplifier is connect with the source electrode of field-effect tube Q2, the negative power end ground connection of operational amplifier.Field-effect tube Q1's The connection of the output end of grid and operational amplifier, also connect with the first end of resistance R7, and the source electrode of field-effect tube Q1 is grounded, also with The second end of resistance R7 connects, and the drain electrode of field-effect tube Q1 is connect with the grid of field-effect tube Q2, also the grid with field-effect tube Q3 Pole connection.The source electrode of field-effect tube Q2 is connect with the source electrode of field-effect tube Q3, the grid of field-effect tube Q2 and the first of resistance R1 End connection, the second end of resistance R1 connect with the source electrode of field-effect tube Q2, also connect with the first end of resistance R7, and the of resistance R7 Two ends are connect with the grid of field-effect tube Q3.The drain electrode of field-effect tube Q2 is for connecting handheld device, the drain electrode of field-effect tube Q3 For connecting power supply unit.

In the case where accessory is formerly connected to handheld device, it is assumed that handheld device output 5V voltage, the first of resistance R2 End can detecte high level, and since the body diode of field-effect tube Q2 is connected, so that the source voltage of field-effect tube Q2 is 5V, so that the first end of resistance R4 and the positive power source terminal of operational amplifier power on.And due to R1=R2, resistance R2's Second end generates 2.5V voltage, i.e. the voltage of the inverting input terminal of operational amplifier is 2.5V.Since the voltage of capacitor C cannot dash forward Become, therefore the voltage of the first end of capacitor C can be gradually increased from 0, so that the non-inverting input terminal of operational amplifier generates voltage evening Voltage is generated in inverting input terminal, so that the output end of operational amplifier exports low level, the i.e. grid of field-effect tube Q1 Source electrode for low level, field-effect tube Q1 is grounded, due to the condition of N-type field-effect tube conducting are as follows: grid voltage is greater than source electrode electricity Pressure, and the grid voltage of field-effect tube Q1 is equal to source voltage, therefore field-effect tube Q1 ends, so that the drain electrode of field-effect tube Q1 Vacantly.Since resistance R1 makes the grid voltage of field-effect tube Q2 and source voltage equal, and resistance R7 makes field-effect tube Q3 Grid voltage and source voltage it is equal, p-type field-effect tube conducting condition be；Grid voltage is less than source voltage, therefore field Effect pipe Q2 and field-effect tube Q3 cut-off.At this point, if power supply unit is connected to handheld device again, due to field-effect tube Q2's Body diode does not turn on, so that the voltage of power supply unit output can not reach handheld device, and due to the body of field-effect tube Q3 two Grade pipe does not turn on, so that the voltage of handheld device output can not reach power supply unit, avoids handheld device and power supply unit It interferes with each other, to realize the protection of handheld device and power supply unit.And after operational amplifier output low level, operation The voltage of the non-inverting input terminal of amplifier becomes 1.67V, the voltage 2.5V of the inverting input terminal of less-than operation amplifier, so that Operational amplifier can continue output low level, will not invert, so that field-effect tube Q2 and field-effect tube Q3 is kept Cut-off.

In the case where power supply unit is formerly connected to handheld device, it is assumed that power supply unit exports the voltage of 5V, due to field The body diode of effect pipe Q3 is connected so that the source voltage of field-effect tube Q2 is 5V so that the first end of resistance R4 and The positive power source terminal of operational amplifier powers on, and due to R4=R5, the second end of resistance R4 generates the voltage of 2.5V, i.e. operation is put The voltage of the non-inverting input terminal of big device is 2.5V.Due to handheld device will not output voltage, the second end of resistance R2 will not Generating voltage, i.e., the voltage of the inverting input terminal of operational amplifier is 0V, therefore the output end of operational amplifier exports high level, I.e. the grid of field-effect tube Q1 is high level, and the source electrode of field-effect tube Q1 is grounded, since the grid voltage of field-effect tube Q1 is greater than Source voltage, therefore field-effect tube Q1 is connected, so that the grounded drain of field-effect tube Q1, the i.e. grid of field-effect tube Q2 and field are imitated Should the grid of pipe Q3 be low level, since the source voltage of field-effect tube Q2 and the source voltage of field-effect tube Q3 are 5V, Therefore field-effect tube Q2 and field-effect tube Q3 is both turned on, and power supply unit can power to handheld device.At this point, the of resistance R2 Two ends can generate the voltage of 2.5V, i.e. the voltage of the inverting input terminal of operational amplifier is 2.5V.And operational amplifier output is high After level, the voltage of the non-inverting input terminal of operational amplifier can become 3.3V, be greater than the inverting input terminal of operational amplifier Voltage 2.5V, enable operational amplifier continue export high level, will not invert so that field-effect tube Q2 and Field-effect tube Q3 is held on.

For another example as shown in Figure 8 A, the homophase input branch 1011 that control module 101 includes includes resistance R4, resistance R5 With capacitor C.Anti-phase input branch 1012 includes resistance R2 and resistance R3.Feedback branch 1013 includes resistance R6.The first transistor 1015 be N-type field-effect tube, and the first extremely source electrode, second extremely drains.The second transistor that first switch module 102 includes is P-type field-effect tube, first extremely drains, the second extremely source electrode.Resistance R1 is provided between the grid and source electrode of second transistor.

In the case where accessory is formerly connected to handheld device, the output end of operational amplifier exports low level.Field-effect Pipe Q1 cut-off, so that the drain electrode of field-effect tube Q1 is hanging.Since resistance R1 makes the grid voltage and source electrode electricity of field-effect tube Q2 Press it is equal, therefore field-effect tube Q2 end.At this point, if power supply unit is connected to handheld device again, due to field-effect tube Q2 Body diode do not turn on so that power supply unit output voltage can not reach handheld device, to realize handheld device With the protection of power supply unit.And resistance R6 enables operational amplifier to continue to export low level, will not invert, to make It obtains field-effect tube Q2 and field-effect tube Q3 and keeps cut-off.

In the case where power supply unit is formerly connected to handheld device, the output end of operational amplifier exports high level.? Effect pipe Q1 conducting, so that the grounded drain of field-effect tube Q1, the i.e. grid of field-effect tube Q2 are low level, due to field-effect tube The source voltage of Q2 is 5V, therefore field-effect tube Q2 is connected, and power supply unit can power to handheld device.And resistance R6 makes Operational amplifier can continue output high level, will not invert, so that field-effect tube Q2 and field-effect tube Q3 is kept Conducting.

Fig. 9 is that another bidirectional power supply provided by the embodiments of the present application protects circuit.As shown in figure 9, the bidirectional power supply is protected Protection circuit may include: control module 201 and first switch module 202.

Wherein, the first end of control module 201 is opened for receiving control signal, the second end of control module 201 with first The second end connection of module 202 is closed, the third end of control module 201 is connect with the third end of first switch module 202, and first opens The first end of module 202 is closed for connecting handheld device, the third end of first switch module 202 is for connecting power supply unit.

It should be noted that the first end of control module 201 is used to connect the place in handheld device in concrete implementation Manage a certain pin of chip, processing chip controls pin persistently exports the control signal of the first level, which can be with For high level, or low level.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is second electrical level by the first level conversion.When controlling signal by the first level conversion is second electrical level, control module 201 can control the closing of first switch module 202.At this point, power supply unit is defeated if power supply unit is connected to handheld device again Voltage out can not interfere the internal circuit of handheld device, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is the first level.When controlling signal is the first level, control module 201 can control first Switch module 202 is opened, so that power supply unit can power to handheld device.

In a kind of possible implementation of the embodiment of the present application, further, as shown in Figure 10, control module 201 It may include: the first transistor and first resistor.In Figure 10 with first resistor be R1 be exemplify.

Wherein, the first pole ground connection of the first transistor, the second level of the first transistor is connect with the first end of resistance R1.The First end of the grid of one transistor for control module 201, the second end of the extremely control module 201 of the second of the first transistor, The second end of resistance R1 is the third end of control module 201.It should be noted that in the embodiment of the present application, the first level is High level, second electrical level are low level.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is converted to low level by high level.When control signal is converted to low level by high level, the first transistor cut-off, from And the first transistor and resistance R1 control first switch module 202 are closed.At this point, if power supply unit is connected to hand-held set again Standby, then the voltage of power supply unit output can not interfere the internal circuit of handheld device, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is high level.When controlling signal is high level, the first transistor conducting, thus control first Switch module 202 is opened, so that power supply unit can power to handheld device.

In the embodiment of the present application, further, as shown in Figure 10, in order to not receive control in the grid of the first transistor When information processed, so that the grid of the first transistor has determining level, so that bidirectional protective circuit is stablized, control module 201 It can also include second resistance.In Figure 10 with second resistance be R2 be exemplify.

Wherein, the grid of the first end of resistance R2 and the first transistor connects, the second end and the first transistor of resistance R2 The first pole connection.

In the alternatively possible implementation of the embodiment of the present application, further, as shown in figure 11, control module 201 may include: input port and 3rd resistor, be R3 with 3rd resistor in Figure 11 be to exemplify.

Wherein, input port is connect with the first end of resistance R3.Input port is the first end of control module 201, resistance The first end of R3 is the second end of control module 201, and the second end of resistance R3 is the third end of control module 201.It needs to illustrate , in the embodiment of the present application, the first level is low level, and second electrical level is high level.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is high level by low transition.When controlling signal by low transition is high level, control module 201 can be controlled First switch module 202 processed is closed.At this point, if power supply unit is connected to handheld device, the voltage of power supply unit output again The internal circuit of handheld device can not be interfered, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is low level.When controlling signal is low level, control module 201 can control first switch Module 202 is opened, so that power supply unit can power to handheld device.

In the embodiment of the present application, further, such as based on Figure 10, as shown in figure 12, first switch module 202 can be with It include: second transistor.

Wherein, the first end of the extremely first switch module 202 of the first of second transistor, the grid of second transistor are the The second end of one switch module 202, the third end of the extremely first switch module 202 of the second of second transistor.

It should be noted that in the embodiment of the present application, the specific structure of control module 201 can also be with reference to this in Figure 12 Apply for the specific structure of control module 201 shown in Fig. 9 in other embodiments, details are not described herein for the embodiment of the present application.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is converted to low level by high level.When control signal is converted to low level by high level, the first transistor cut-off, from And the first transistor and resistance R1 control second transistor cut-off.At this point, being supplied if power supply unit is connected to handheld device again The voltage of electric equipment output can not interfere the internal circuit of handheld device, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is high level.When controlling signal is high level, the first transistor conducting, thus control second Transistor turns, so that power supply unit can power to handheld device.

In the embodiment of the present application, further, such as based on Figure 11, as shown in figure 13, first switch module 202 can be with It include: second transistor.

It should be noted that in the embodiment of the present application, the specific structure of control module 201 can also be with reference to this in Figure 13 Apply for the specific structure of control module 201 shown in Fig. 9 in another embodiment, details are not described herein for the embodiment of the present application.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is high level by low transition.When controlling signal by low transition is high level, control second transistor is cut Only.At this point, the voltage of power supply unit output can not interfere the interior of handheld device if power supply unit is connected to handheld device again Portion's circuit, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is low level.When controlling signal is low level, control second transistor conducting, to power Equipment can power to handheld device.

In the embodiment of the present application, further, as shown in figure 14, defeated in order to solve handheld device such as based on Figure 12 The problem of voltage out interferes power supply unit, it can also include: the 4th resistance 203 which, which protects circuit, with And it is set to the second switch module 204 between first switch module 202 and power supply unit.With the 4th resistance 203 in Figure 14 It is to exemplify for R4.

Wherein, the first end of second switch module 204 is connect with the third end of first switch module 202, second switch mould The second end of block 204 is connect with the second end of first switch module 202, and the third end of second switch module 204 is supplied for connecting Electric equipment.The first end of resistance R4 is connect with the first end of second switch module 204, the second end and second switch mould of resistance R4 The second end of block 204 connects.

It the specific structure of control module 201 and first is opened it should be noted that in the embodiment of the present application, in Figure 14 The specific structure of module 202 is closed, it can also be accordingly with reference to Fig. 9 and control module shown in Fig. 10 in the application other embodiments 201 specific structure and the specific structure of first switch module 202, details are not described herein for the embodiment of the present application.

In the embodiment of the present application, further, as shown in Figure 14 A, second switch module 204 may include third crystal Pipe.

Wherein, the first end of the extremely second switch module 204 of the first of third transistor, the grid of third transistor are the The second end of two switch modules 204, the third end of the extremely second switch module 204 of the second of third transistor.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is converted to low level by high level.When control signal is converted to low level by high level, the first transistor cut-off, from And the first transistor and resistance R1 control second transistor cut-off, the first transistor and resistance R4 control third transistor cut-off. At this point, the voltage of power supply unit output can not reach handheld device, while hand if power supply unit is connected to handheld device again The voltage of holding equipment output can not also reach power supply unit, avoid interfering with each other for handheld device and power supply unit, thus real The protection of handheld device and power supply unit is showed.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is high level.When controlling signal is high level, the first transistor conducting, thus control second Transistor and third transistor conducting, so that power supply unit can power to handheld device.

In the embodiment of the present application, further, as shown in figure 15, defeated in order to solve handheld device such as based on Figure 13 The problem of voltage out interferes power supply unit, it can also include: the 4th resistance 203 which, which protects circuit, with And it is set to the second switch module 204 between first switch module 202 and power supply unit.With the 4th resistance 203 in Figure 15 It is to exemplify for R4.

It the specific structure of control module 201 and first is opened it should be noted that in the embodiment of the present application, in Figure 15 The specific structure of module 202 is closed, control module shown in Fig. 9 and Figure 11 in the application other embodiments can also be accordingly referred to 201 specific structure and the specific structure of first switch module 202, details are not described herein for the embodiment of the present application.

In the embodiment of the present application, further, as shown in fig. 15, second switch module 204 may include third crystal Pipe.

In the case where accessory is formerly connected to handheld device, handheld device output voltage is powered to accessory, and controls control Signal processed is high level by low transition.When control signal by low transition be high level when, control second transistor and Third transistor cut-off.At this point, the voltage of power supply unit output can not reach if power supply unit is connected to handheld device again Handheld device, while the voltage of handheld device output can not also reach power supply unit, avoid handheld device and power supply unit It interferes with each other, to realize the protection of handheld device and power supply unit.

In the case where power supply unit is formerly connected to handheld device, power supply unit output voltage is powered to handheld device, And keeping the control signal of output is low level.When controlling signal is low level, second transistor and third transistor are controlled Conducting, so that power supply unit can power to handheld device.

In one kind of the embodiment of the present application can be able to achieve, for example, the first transistor that control module 201 includes is N-type Field-effect tube, the first extremely source electrode, second extremely drains.The second transistor that first switch module 202 includes is p-type field-effect Pipe, first extremely drains, the second extremely source electrode.The third transistor that second switch module 204 includes is p-type field-effect tube, the One extremely source electrode, second extremely drains.And resistance R2 is provided between the grid and source electrode of the first transistor.In the second crystal Resistance R1 is provided between the grid and source electrode of pipe.It is right for resistance R4 to be provided between the grid and source electrode of third transistor Bidirectional power supply protection circuit is illustrated.

It specifically, bidirectional power supply protection circuit is as shown in figure 16, and is Q1, the second crystal with the first transistor in Figure 16 Pipe is Q2, and third transistor is that Q3 is to exemplify.Wherein, the grid of field-effect tube Q1 is connect with the first end of resistance R2, field effect Should pipe Q1 source electrode ground connection, also connect with the second end of resistance R2, the grid company of the drain electrode of field-effect tube Q1 and field-effect tube Q2 It connects, is also connect with the grid of field-effect tube Q3.The source electrode of field-effect tube Q2 is connect with the source electrode of field-effect tube Q3, field-effect tube Q2 Grid connect with the first end of resistance R1, the second end of resistance R1 is connect with the source electrode of field-effect tube Q2, also with resistance R4's First end connection, the second end of resistance R4 are connect with the grid of field-effect tube Q3.The grid of field-effect tube Q1 is for receiving control Signal, the drain electrode of field-effect tube Q2 is for connecting handheld device, and the drain electrode of field-effect tube Q3 is for connecting power supply unit.

In the case where accessory is formerly connected to handheld device, it is assumed that handheld device exports the voltage of 5V, due to field-effect The body diode of pipe Q2 is connected, therefore the source electrode of field-effect tube Q2 generates the voltage of 5V.And handheld device control control signal by High level is converted to low level, when control signal is converted to low level by high level, due to the grid voltage of field-effect tube Q1 It is 0V with source voltage, therefore field-effect tube Q1 ends, so that the drain electrode of field-effect tube Q1 is hanging.Since resistance R1 makes field The grid voltage and source voltage of effect pipe Q2 is 5V, therefore field-effect tube Q2 ends, since resistance R4 makes field-effect tube The grid voltage and source voltage of Q3 is 5V, therefore field-effect tube Q3 ends.At this point, if power supply unit is connected to again hand-held Equipment, then since the body diode of field-effect tube Q2 does not turn on, so that the voltage of power supply unit output can not reach handheld device, And since the body diode of field-effect tube Q3 does not turn on, so that the voltage of handheld device output can not reach power supply unit, avoid Handheld device and power supply unit interfere with each other, to realize the protection of handheld device and power supply unit.

In the case where power supply unit is formerly connected to handheld device, it is high electricity that handheld device, which keeps the control signal of output, Flat, when controlling signal is high level, since the grid voltage of field-effect tube Q1 is greater than source voltage, field-effect tube Q1 is led It is logical, so that the drain voltage of field-effect tube Q1 is 0V, the i.e. grid voltage of the grid voltage of field-effect tube Q2 and field-effect tube Q3 It is 0V.Assuming that the voltage of power supply unit output 5V, since the body diode of field-effect tube Q3 is connected, so that field-effect tube Q3 The voltage of source electrode generation 5V.Since the grid voltage of field-effect tube Q2 is less than source voltage, field-effect tube Q2 conducting.Together Reason, field-effect tube Q3 conducting.Power supply unit can power to handheld device in this way.

For another example as shown in Figure 16 A, the first transistor that control module 201 includes is N-type field-effect tube, and first extremely Source electrode, second extremely drains.The second transistor that first switch module 202 includes is p-type field-effect tube, and first extremely drains, Second extremely source electrode.And resistance R2 is provided between the grid and source electrode of the first transistor.Second transistor grid and Resistance R1 is provided between source electrode.

In the case where accessory is formerly connected to handheld device, when control signal is converted to low level by high level, field Effect pipe Q1 cut-off.Since resistance R1 makes the grid voltage of field-effect tube Q2 and source voltage is 5V, field-effect tube Q2 cut-off.At this point, since the body diode of field-effect tube Q2 does not turn on, making if power supply unit is connected to handheld device again The voltage for obtaining power supply unit output can not reach handheld device, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, when controlling signal is high level, field-effect tube Q1 Conducting, so that the grid voltage of field-effect tube Q2 is 0V.Assuming that the voltage of power supply unit output 5V, the source electrode of field-effect tube Q2 produce The voltage of raw 5V.Since the grid voltage of field-effect tube Q2 is less than source voltage, field-effect tube Q2 conducting.Power supply is set in this way It is standby to power to handheld device.

In another realization of the embodiment of the present application, for example, the second transistor that first switch module 202 includes is P Type field-effect tube, first extremely drains, the second extremely source electrode.The third transistor that second switch module packet 204 includes is p-type field Effect pipe, the first extremely source electrode, second extremely drains.And resistance R3 is provided between the grid and source electrode of second transistor. Resistance R4 is provided between the grid and source electrode of third transistor.

It specifically, bidirectional power supply protection circuit is as shown in figure 17, and is Q2, third crystal with second transistor in Figure 17 Pipe is that Q3 is to exemplify.Wherein, the source electrode of field-effect tube Q2 is connect with the source electrode of field-effect tube Q3, the grid of field-effect tube Q2 with The first end of resistance R3 connects, and is also used to receive control signal.The second end of resistance R3 is connect with the source electrode of field-effect tube Q2, also It is connect with the first end of resistance R4.The second end of resistance R4 is connect with the grid of field-effect tube Q3, is also used to receive control signal. The drain electrode of field-effect tube Q2 is for connecting handheld device, and the drain electrode of field-effect tube Q3 is for connecting power supply unit.

In the case where accessory is formerly connected to handheld device, it is assumed that handheld device exports the voltage of 5V, due to field-effect The body diode of pipe Q2 is connected, so that the source electrode of field-effect tube Q2 generates the voltage of 5V.And handheld device control control signal by Low transition is high level, when controlling signal by low transition is high level, due to the grid voltage of field-effect tube Q2 It is 5V with source voltage, therefore field-effect tube Q2 ends.Similarly, field-effect tube Q3 ends.At this point, if power supply unit is connected again It is connected to handheld device, then since the body diode of field-effect tube Q2 does not turn on, so that the voltage of power supply unit output can not reach Handheld device, and since the body diode of field-effect tube Q3 does not turn on, so that the voltage of handheld device output can not reach power supply Equipment avoids interfering with each other for handheld device and power supply unit, to realize the protection of handheld device and power supply unit.

In the case where power supply unit is formerly connected to handheld device, it is assumed that power supply unit exports the voltage of 5V, then by It is connected in the body diode of field-effect tube Q3, the source electrode of field-effect tube Q3 can generate the voltage of 5V.Handheld device keeps output Control signal is low level, when controlling signal is low level, since the grid voltage 0V of field-effect tube Q2 is less than source voltage 5V, therefore field-effect tube Q2 is connected.Similarly, field-effect tube Q3 is connected.Power supply unit can power to handheld device in this way.

For another example as shown in Figure 17 A, the second transistor that first switch module 202 includes be p-type field-effect tube, first Extremely drain, the second extremely source electrode.And resistance R3 is provided between the grid and source electrode of second transistor.

In the case where accessory is formerly connected to handheld device, when controlling signal by low transition is high level, field Effect pipe Q2 cut-off.At this point, if power supply unit is connected to handheld device again, since the body diode of field-effect tube Q2 is not led It is logical, so that the voltage of power supply unit output can not reach handheld device, to realize the protection of handheld device.

In the case where power supply unit is formerly connected to handheld device, when controlling signal is low level, field-effect tube Q2 Conducting.Power supply unit can power to handheld device in this way.

Figure 18 is that another bidirectional power supply provided by the embodiments of the present application protects circuit.As shown in figure 18, bidirectional power supply is protected Protection circuit may include: input port 301 and first switch module 302.

Wherein, input port 301 is also connect with the second end of first switch module 302, first for receiving control signal The first end of switch module 302 is for connecting handheld device, and the third end of first switch module 302 is for connecting power supply unit.

In the embodiment of the present application, further, first switch module 302 may include the first transistor.Wherein, first The first end of the extremely first switch module 302 of the first of transistor, the grid of the first transistor are the of first switch module 302 Two ends, the third end of the extremely first switch module 302 of the second of the first transistor.

In the embodiment of the present application, further, bidirectional power supply protection circuit can also include being set to the first transistor Second switch module 303 between power supply unit, which may include second transistor.

Wherein, the first pole of second transistor and the second pole of the first transistor connect, the grid of the first transistor and the The grid of one transistor connects, and the second pole of second transistor is for connecting power supply unit.

It should be noted that specific implementation and another reality of the application in the embodiment of the present application in bidirectional power supply protection circuit The specific implementation for applying the bidirectional power supply protection circuit of Figure 17 in example is similar, the tool of bidirectional power supply protection circuit in the embodiment of the present application Body is realized can be with reference to the specific implementation of bidirectional power supply protection circuit in another embodiment Figure 17, and the application is no longer superfluous in detail herein It states.

Figure 19 be a kind of handheld device provided by the embodiments of the present application, as shown in figure 19, the handheld device may include: as Any bidirectional power supply protects circuit in Fig. 1-Fig. 5, Fig. 5 A, Fig. 8 and Fig. 8 A, alternatively, such as Fig. 9-Figure 17, Yi Jitu Any bidirectional power supply protects circuit in 17A, alternatively, as the bidirectional power supply in Figure 18 protects circuit.

Handheld device provided by the embodiments of the present application include above-mentioned bidirectional power supply protect circuit, therefore can achieve with it is above-mentioned Bidirectional power supply protects the identical effect of circuit.

Figure 20 be a kind of switching device provided by the embodiments of the present application, as shown in figure 20, the switching device may include: as Any bidirectional power supply protects circuit in Fig. 1-Fig. 5, Fig. 5 A, Fig. 8 and Fig. 8 A, alternatively, such as Fig. 9-Figure 17, Yi Jitu Any bidirectional power supply protects circuit in 17A, alternatively, as the bidirectional power supply in Figure 18 protects circuit.

Switching device provided by the embodiments of the present application include above-mentioned bidirectional power supply protect circuit, therefore can achieve with it is above-mentioned Bidirectional power supply protects the identical effect of circuit.

Figure 21 is that one kind provided by the embodiments of the present application is applied to such as Fig. 1-Fig. 5, any institute in Fig. 5 A, Fig. 8 and Fig. 8 A The control method for the bidirectional power supply protection circuit stated, as shown in figure 21, this method comprises:

If 401, the first end of control module detects high level, first switch module is controlled by control module and is closed It closes.

If 402, the third end of control module detects high level, first switch module is controlled by control module and is opened It opens.

The control method of bidirectional power supply protection circuit provided by the embodiments of the present application, including control module and first switch mould Block controls first switch module by control module and closes if the first end of control module detects high level.In this way, In the case where accessory is first connected to handheld device, the first end of handheld device output voltage, control module can be detected High level controls first switch module by control module and closes.If power supply unit is connected to handheld device again at this time, supply The voltage of electric equipment output can not reach handheld device, i.e., the voltage of power supply unit output can not handheld device internal circuit It interferes, realizes the protection of handheld device.

Figure 22 is a kind of pair being applied to as described in any in Fig. 9-Figure 17 and Figure 17 A provided by the embodiments of the present application To the control method of power supply protection circuit, as shown in figure 22, this method comprises:

501, when the control signal that the first end of control module receives is second electrical level by the first level conversion, pass through Control module controls first switch module and closes.

502, when the control signal that the first end of control module receives is the first level, pass through control module control the One switch module is opened.

The control method of bidirectional power supply protection circuit provided by the embodiments of the present application, including control module and first switch mould Block passes through control module when the control signal that the first end of control module receives is second electrical level by the first level conversion First switch module is controlled to close.In this way, in the case where accessory is formerly connected to handheld device, handheld device output voltage, And controlling control signal by the first level conversion is second electrical level, when controlling signal by the first level conversion is second electrical level, First switch module is controlled by control module to close.If power supply unit is connected to handheld device, power supply unit again at this time The voltage of output can not reach handheld device, i.e., the voltage of power supply unit output can not the internal circuit of handheld device cause to do It disturbs, realizes the protection of handheld device.

Through the above description of the embodiments, it is apparent to those skilled in the art that, for description It is convenienct and succinct, only the example of the division of the above functional modules, in practical application, can according to need and will be upper It states function distribution to be completed by different functional modules, i.e., the internal structure of device is divided into different functional modules, to complete All or part of function described above.

In several embodiments provided herein, it should be understood that disclosed device and method can pass through it Its mode is realized.For example, the apparatus embodiments described above are merely exemplary, for example, the module or unit It divides, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or components It may be combined or can be integrated into another device, or some features can be ignored or not executed.Another point, it is shown or The mutual coupling, direct-coupling or communication connection discussed can be through some interfaces, the indirect coupling of device or unit It closes or communicates to connect, can be electrical property, mechanical or other forms.

The unit as illustrated by the separation member may or may not be physically separated, aobvious as unit The component shown can be a physical unit or multiple physical units, it can and it is in one place, or may be distributed over Multiple and different places.Some or all of unit therein can be selected to realize this embodiment scheme according to the actual needs Purpose.

It, can also be in addition, each functional unit in each embodiment of the application can integrate in one processing unit It is that each unit physically exists alone, can also be integrated in one unit with two or more units.Above-mentioned integrated list Member both can take the form of hardware realization, can also realize in the form of software functional units.

If the integrated unit is realized in the form of SFU software functional unit and sells or use as independent product When, it can store in a read/write memory medium.Based on this understanding, the technical solution of the embodiment of the present application is substantially The all or part of the part that contributes to existing technology or the technical solution can be in the form of software products in other words It embodies, which is stored in a storage medium, including some instructions are used so that an equipment (can be list Piece machine, chip etc.) or processor (processor) execute each embodiment the method for the application all or part of the steps. And storage medium above-mentioned includes；USB flash disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), arbitrary access are deposited The various media that can store program code such as reservoir (Random Access Memory, RAM), magnetic or disk.

The above, the only specific embodiment of the application, but the protection scope of the application is not limited thereto, it is any Change or replacement within the technical scope of the present application should all be covered within the scope of protection of this application.Therefore, this Shen Protection scope please should be based on the protection scope of the described claims.

Claims

1. a kind of bidirectional power supply protects circuit, which is characterized in that the bidirectional power supply protection circuit includes: control module and first Switch module；

The first end of the control module is connect with the first end of the first switch module, the second end of the control module with The second end of the first switch module connects, and the third end of the third end of the control module and the first switch module connects It connects, the first end of the first switch module is for connecting handheld device, and the third end of the first switch module is for connecting Power supply unit；

If the first end of the control module detects high level, the control module controls the first switch module and closes It closes.

2. bidirectional power supply according to claim 1 protects circuit, which is characterized in that if the third end of the control module is examined High level is measured, then the control module controls the first switch module and opens.

3. bidirectional power supply according to claim 1 or 2 protects circuit, which is characterized in that the control module includes: same phase Input branch, anti-phase input branch, feedback branch, operational amplifier, the first transistor and first resistor；

The first end of the homophase input branch connects to power supply, the second end of the homophase input branch and the operation amplifier The non-inverting input terminal of device connects, the third end ground connection of the homophase input branch；The second end of the anti-phase input branch and institute State the inverting input terminal connection of operational amplifier, the third end ground connection of the anti-phase input branch；The first of the feedback branch End is connect with the non-inverting input terminal of the operational amplifier, the output of the second end of the feedback branch and the operational amplifier End connection；The positive power source terminal of the operational amplifier is connect with the power supply, the negative power end ground connection of the operational amplifier；Institute The grid for stating the first transistor is connect with the output end of the operational amplifier, the first pole ground connection of the first transistor, institute The second level for stating the first transistor is connect with the first end of the first resistor；

The first end of the anti-phase input branch is the first end of the control module, and the second level of the first transistor is institute The second end of control module is stated, the second end of the first resistor is the third end of the control module；

If the first end of the control module detects high level, the fortune is inputted by the second end of the anti-phase input branch The voltage for calculating the inverting input terminal of amplifier, which is higher than, inputs the operational amplifier by the second end of the homophase input branch The voltage of non-inverting input terminal, the output end of the operational amplifier export low level, the first transistor cut-off, thus described The first transistor and the first resistor control the first switch module and close；The feedback branch is for putting the operation The voltage of the inverting input terminal of big device is persistently higher than the voltage of the non-inverting input terminal of the operational amplifier；

If the third end of the control module detects high level, the fortune is inputted by the second end of the anti-phase input branch The voltage for calculating the inverting input terminal of amplifier, which is lower than, inputs the operational amplifier by the second end of the homophase input branch The voltage of non-inverting input terminal, the output end of the operational amplifier export high level, the first transistor conducting, to control The first switch module is opened；It is low that the feedback branch is used to make the voltage of the inverting input terminal of the operational amplifier to continue In the voltage of the non-inverting input terminal of the operational amplifier.

4. bidirectional power supply according to claim 3 protects circuit, which is characterized in that the anti-phase input branch includes: the Two resistance and 3rd resistor；

The second end of the second resistance is connect with the first end of the 3rd resistor；

The first end of the second resistance is the first end of the anti-phase input branch, and the second end of the second resistance is described The second end of reversed input branch, the second end of the 3rd resistor are the third end of the reversed input branch.

5. bidirectional power supply according to claim 3 or 4 protects circuit, which is characterized in that the homophase input branch includes: 4th resistance, the 5th resistance and capacitor；

The second end of 4th resistance is connect with the first end of the 5th resistance, is also connect with the first end of the capacitor, The second end of the capacitor is connect with the second end of the 5th resistance；

The first end of 4th resistance is the first end of the homophase input branch, and the second end of the 4th resistance is described The second end of homophase input branch, the second end of the 5th resistance are the third end of the homophase input branch.

6. the bidirectional power supply according to any one of claim 3-5 protects circuit, which is characterized in that the feedback branch packet It includes: the 6th resistance.

7. bidirectional power supply according to claim 1 to 6 protects circuit, which is characterized in that the first switch mould Block includes: second transistor；

The first end of the extremely described first switch module of the first of the second transistor, the grid of the second transistor is institute State the second end of first switch module, the third end of the extremely described first switch module of the second of the second transistor；

If the first end of the control module detects high level, the control module controls the second transistor cut-off； If the third end of the control module detects high level, the control module controls the second transistor conducting.

8. bidirectional power supply described in any one of -7 protects circuit according to claim 1, which is characterized in that the bidirectional power supply is protected Protection circuit further include: the 7th resistance, and the second switch being set between the first switch module and the power supply unit Module；

The first end of the second switch module is connect with the third end of the first switch module, the second switch module Second end is connect with the second end of the first switch module, and the third end of the second switch module is for connecting the power supply Equipment；The first end of 7th resistance is connect with the first end of the second switch module, the second end of the 7th resistance It is connect with the second end of the second switch module；

If the first end of the control module detects high level, the control module controls the first switch module and institute State the closing of second switch module；

If the third end of the control module detects high level, the control module controls the first switch module and institute State the unlatching of second switch module.

9. bidirectional power supply according to claim 8 protects circuit, which is characterized in that the second switch module includes: the Three transistors；

The first end of the extremely described second switch module of the first of the third transistor, the grid of the third transistor is institute State the second end of second switch module, the third end of the extremely described second switch module of the second of the third transistor；

If the first end of the control module detects high level, the control module controls the second transistor and described Third transistor cut-off；

If the third end of the control module detects high level, the control module controls the second transistor and described Third transistor conducting.

10. a kind of bidirectional power supply protects circuit, which is characterized in that the bidirectional power supply protection circuit includes: control module and the One switch module；

The first end of the control module is for receiving control signal, the second end of the control module and the first switch mould The second end of block connects, and the third end of the control module is connect with the third end of the first switch module, and described first opens The first end of module is closed for connecting handheld device, the third end of the first switch module is for connecting power supply unit；

When the control signal is second electrical level by the first level conversion, the control module controls the first switch module It closes.

11. bidirectional power supply according to claim 10 protects circuit, which is characterized in that

When the control signal is first level, the control module controls the first switch module and opens.

12. bidirectional power supply described in 0 or 11 protects circuit according to claim 1, which is characterized in that the control module includes: The first transistor and first resistor；

First pole of the first transistor is grounded, and the first end of the second level of the first transistor and the first resistor connects It connects；

The grid of the first transistor is the first end of the control module, the extremely described control of the second of the first transistor The second end of molding block, the second end of the first resistor are the third end of the control module；

When the control signal is the second electrical level by first level conversion, the first transistor cut-off, thus The first transistor and the first resistor control the first switch module and close；

When the control signal is first level, the first transistor conducting, to control the first switch mould Block is opened.

13. bidirectional power supply according to claim 12 protects circuit, which is characterized in that the control module further include: the Two resistance；

The first end of the second resistance is connect with the grid of the first transistor, the second end of the second resistance with it is described First pole of the first transistor connects.

14. bidirectional power supply according to claim 12 or 13 protects circuit, which is characterized in that the control module includes: Input port and 3rd resistor；

The input port is connect with the first end of the 3rd resistor；

The input port is the first end of the control module, and the first end of the 3rd resistor is the of the control module Two ends, the second end of the 3rd resistor are the third end of the control module.

15. bidirectional power supply described in any one of 0-14 protects circuit according to claim 1, which is characterized in that described first opens Closing module includes: second transistor；

When the control signal is the second electrical level by first level conversion, the control module control described second Transistor cutoff；

When the control signal is first level, the control module controls the second transistor conducting.

16. bidirectional power supply described in any one of 0-15 protects circuit according to claim 1, which is characterized in that the two-way confession Electric protection circuit further include: the 4th resistance, and be set between the first switch module and the power supply unit second Switch module；

The first end of the second switch module is connect with the third end of the first switch module, the second switch module Second end is connect with the second end of the first switch module, and the third end of the second switch module is for connecting the power supply Equipment；The first end of 4th resistance is connect with the first end of the second switch module, the second end of the 4th resistance It is connect with the second end of the second switch module；

When the control signal is the second electrical level by first level conversion, the control module control described first Switch module and the second switch module are closed；

When the control signal is first level, the control module controls the first switch module and described second Switch module is opened.

17. bidirectional power supply according to claim 16 protects circuit, which is characterized in that the second switch module includes: Third transistor；

When the control signal is the second electrical level by first level conversion, the control module control described second Transistor and third transistor cut-off；

When the control signal is first level, the control module controls the second transistor and the third is brilliant The conducting of body pipe.

18. a kind of handheld device, which is characterized in that the handheld device includes:

Bidirectional power supply as described in any one of claim 1-17 protects circuit.

19. a kind of switching device, which is characterized in that the switching device includes: