CN209184579U - A kind of analog switching circuit - Google Patents

A kind of analog switching circuit Download PDF

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Publication number
CN209184579U
CN209184579U CN201822150934.XU CN201822150934U CN209184579U CN 209184579 U CN209184579 U CN 209184579U CN 201822150934 U CN201822150934 U CN 201822150934U CN 209184579 U CN209184579 U CN 209184579U
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China
Prior art keywords
transistor
switch
electrically connected
voltage
drain electrode
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CN201822150934.XU
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Chinese (zh)
Inventor
何均
张启帆
张海军
邵派
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Shanghai Awinic Technology Co Ltd
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Shanghai Awinic Technology Co Ltd
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Abstract

The utility model provides a kind of analog switching circuit, and charge pump generates control voltage according to the voltage of the substrate of first switch, and controls first switch conducting by control voltage, stops exporting the control voltage, control first switch disconnects;First bleeder circuit is used in first switch conducting, first voltage is provided to the substrate of first switch, first voltage is equal to the sum of voltage and first voltage difference of the source electrode of first switch, and first voltage difference is equal to the half of the voltage difference between the source electrode of first switch and the drain electrode of first switch;First voltage selection circuit is used for after the voltage of the drain electrode of first switch is pulled down to ground by pull-down circuit, and the reckling in the voltage of the drain electrode of the voltage of the source electrode of first switch and first switch is transferred to the substrate of first switch.By charge pump instead of Zener diode in the utility model, the requirement due to charge pump to manufacture craft is lower than Zener diode, requirement of the analog switching circuit to manufacture craft can be reduced.

Description

A kind of analog switching circuit
Technical field
The utility model relates to analog switch technical fields, more specifically to a kind of analog switching circuit.
Background technique
Analog switch plays a part of the input signal of input terminal being transmitted to output end.Fig. 1 is a kind of existing list N pipe The working principle of the structural schematic diagram of analog switching circuit, this list N pipe analog switching circuit is: booster circuit generates high electricity Pressure, current source I is to bias Zener diode Z, under the breakdown pressure stabilization function of Zener diode Z, the grid of analog switch M1 The stable pressure stabilizing value in Zener diode Z of pressure difference between G0 and source S 0 will input so as to open analog switch M0 The input signal of end VIN0 is transmitted to output end VOUT0.But since Zener diode there are certain requirements manufacture craft, because This, significantly limits the realization of analog switching circuit.
Utility model content
In view of this, the present invention provides a kind of analog switching circuits, cause to avoid using Zener diode The analog switching circuit problem more demanding to manufacture craft.
To achieve the above object, the utility model provides the following technical solutions:
A kind of analog switching circuit, including charge pump, first switch, the first bleeder circuit, first voltage selection circuit and Pull-down circuit;
The substrate electrical connection of the input terminal of the charge pump and the first switch;First output end of the charge pump with The grid of the first switch is electrically connected;The charge pump is used for after the first control signal for receiving control terminal output, root Control voltage is generated according to the voltage of the substrate of the first switch, and the first switch is controlled by the control voltage and is led It is logical, after the second control signal for receiving the control terminal output, stop exporting the control voltage, to control described first Switch disconnects;
First bleeder circuit is used in first switch conducting, and the substrate of Xiang Suoshu first switch provides first Voltage, the first voltage are equal to the sum of voltage and first voltage difference of the source electrode of the first switch, and the first voltage is poor Equal to the half of the voltage difference between the source electrode of the first switch and the drain electrode of the first switch;
The pull-down circuit is used for after the second control signal for receiving the control terminal output, by the first switch The voltage of drain electrode pull down to ground;
The first voltage selection circuit is used to pull down the voltage of the drain electrode of the first switch in the pull-down circuit To after ground, the reckling in the voltage of the drain electrode of the voltage of the source electrode of the first switch and the first switch is transferred to institute State the substrate of first switch.
It optionally, further include second switch, the second bleeder circuit and second voltage selection circuit;The source of the second switch Pole is electrically connected with the drain electrode of the first switch;
First output end of the charge pump is electrically connected with the grid of the second switch;The charge pump is for receiving After the first control signal exported to the control terminal, the second switch is controlled by the control voltage and is connected, is being received After the second control signal exported to the control terminal, stop exporting the control voltage, be disconnected with controlling the second switch;
Second bleeder circuit is used in second switch conducting, and the substrate of Xiang Suoshu second switch provides third Voltage, the tertiary voltage are equal to the sum of voltage and second voltage difference of the source electrode of the second switch, and the second voltage is poor Equal to the half of the voltage difference between the drain electrode of the source electrode and the second switch of the second switch;
The pull-down circuit is also used to after the second control signal for receiving the control terminal output, and described second is opened The voltage of the source electrode of pass pulls down to ground;
The second voltage selection circuit is used to pull down the voltage of the source electrode of the second switch in the pull-down circuit To after ground, the reckling in the voltage of the drain electrode of the voltage of the source electrode of the second switch and the second switch is transferred to institute State the substrate of second switch.
Optionally, the first bleeder circuit includes the first transistor and second transistor;
The substrate electrical connection of the substrate of the first transistor and the first switch, the grid of the first transistor with The grid of the first switch is electrically connected, and the drain electrode of the first transistor is electrically connected with the source electrode of the first switch, described The substrate electrical connection of the source electrode of the first transistor and the first transistor;
The substrate electrical connection of the substrate of the second transistor and the first switch, the grid of the second transistor with The grid of the first switch is electrically connected, and the drain electrode of the second transistor is electrically connected with the drain electrode of the first switch, described The substrate electrical connection of the source electrode of second transistor and the second transistor.
Optionally, the first voltage selection circuit includes third transistor and the 4th transistor;
The substrate electrical connection of the substrate of the third transistor and the first switch, the grid of the third transistor with The drain electrode of the first switch is electrically connected, and the drain electrode of the third transistor is electrically connected with the source electrode of the first switch, described The substrate electrical connection of the source electrode of third transistor and the third transistor;
The substrate electrical connection of the substrate of 4th transistor and the first switch, the grid of the 4th transistor with The source electrode of the first switch is electrically connected, and the drain electrode of the 4th transistor is electrically connected with the drain electrode of the first switch, described The substrate electrical connection of the source electrode of 4th transistor and the 4th transistor.
Optionally, the second bleeder circuit includes the 5th transistor and the 6th transistor;
The substrate electrical connection of the substrate of 5th transistor and the second switch, the grid of the 5th transistor with The grid of the second switch is electrically connected, and the drain electrode of the 5th transistor is electrically connected with the source electrode of the second switch, described The substrate electrical connection of the source electrode of 5th transistor and the 5th transistor;
The substrate electrical connection of the substrate of 6th transistor and the second switch, the grid of the 6th transistor with The grid of the second switch is electrically connected, and the drain electrode of the 6th transistor is electrically connected with the drain electrode of the second switch, described The substrate electrical connection of the source electrode of 6th transistor and the 6th transistor.
Optionally, the second voltage selection circuit includes the 7th transistor and the 8th transistor;
The substrate electrical connection of the substrate of 7th transistor and the second switch, the grid of the 7th transistor with The drain electrode of the second switch is electrically connected, and the drain electrode of the 7th transistor is electrically connected with the source electrode of the second switch, described The substrate electrical connection of the source electrode of 7th transistor and the 7th transistor;
The substrate electrical connection of the substrate of 8th transistor and the second switch, the grid of the 8th transistor with The source electrode of the second switch is electrically connected, and the drain electrode of the 8th transistor is electrically connected with the drain electrode of the second switch, described The substrate electrical connection of the source electrode of 8th transistor and the 8th transistor.
Optionally, the pull-down circuit includes the 9th transistor;The grid of 9th transistor and control terminal electricity Connection, the source electrode of the 9th transistor are electrically connected with the source electrode of the drain electrode of the first switch and second switch, and the described 9th The drain electrode of transistor is electrically connected with ground terminal, and the substrate of the 9th transistor and the second output terminal of the charge pump are electrically connected It connects.
Optionally, the charge pump includes the tenth transistor to the 20th transistor, first capacitor and the second capacitor;
The grid of tenth transistor is electrically connected with the drain electrode of the 11st transistor, the source of the tenth transistor Pole is electrically connected with the input terminal of the charge pump, and the drain electrode of the tenth transistor and the grid of the 11st transistor are electrically connected It connects, the source electrode of the 11st transistor is electrically connected with the input terminal of the charge pump;
The drain electrode of tenth transistor is also electrically connected with the first end of the first capacitor, and the second of the first capacitor End is electrically connected with the first signal end;The drain electrode of 11st transistor is electrically connected with the first end of the second capacitor, and described second The second end of capacitor is electrically connected with second signal end;
The source electrode of tenth two-transistor is electrically connected with the drain electrode of the tenth transistor, the tenth two-transistor Drain electrode is electrically connected with the output end of the charge pump, the grid of the tenth two-transistor and the source electrode of the 13rd transistor Electrical connection, the grid of the 13rd transistor are electrically connected with the source electrode of the tenth two-transistor, the 13rd transistor Drain electrode be electrically connected with the output end of the charge pump, the substrate of the 13rd transistor and the lining of the tenth two-transistor Bottom is electrically connected with the source electrode of the 14th transistor;
The drain electrode of 14th transistor is electrically connected with the output end of the charge pump, the grid of the 14th transistor Pole is electrically connected with the drain electrode of the 15th transistor, the source electrode of the 15th transistor and the source of the 14th transistor Pole electrical connection, the grid of the 15th transistor are electrically connected with the drain electrode of the 14th transistor;
The grid of 16th transistor is electrically connected with the drain electrode of the 17th transistor, the 17th transistor Grid be electrically connected with the drain electrode of the 16th transistor, drain electrode and the input of the charge pump of the 16th transistor End electrical connection, the drain electrode of the 17th transistor are electrically connected with ground terminal, the 16th transistor and the 17th crystalline substance The source electrode of body pipe is electrically connected with the source electrode of the 18th transistor;
The source electrode of the source electrode and the 19th transistor of 19th transistor and the 20th transistor is electrically connected It connects, the grid of the 18th transistor, the 19th transistor and the 20th transistor is electrically connected with the control terminal It connects, the drain electrode of the 18th transistor is electrically connected with the first end of the first capacitor, the drain electrode of the 19th transistor It is electrically connected with the first end of second capacitor, the drain electrode of the 20th transistor and the output end of the charge pump are electrically connected It connects.
Optionally, the tenth two-transistor to the 15th transistor be PMOS transistor, the tenth transistor, 11st transistor, the 16th transistor to the 20th transistor are NMOS transistor.
Optionally, the first switch and the second switch are NMOS transistor.
Compared with prior art, technical solution provided by the utility model has the advantage that
Analog switching circuit provided by the utility model controls the conducting and disconnection of first switch by charge pump, When first switch is connected, first voltage is provided to the substrate of first switch by the first bleeder circuit, since first voltage is equal to The sum of the voltage of the source electrode of first switch and first voltage difference, and first voltage difference can be ignored, therefore, first voltage etc. In the voltage of the source electrode of first switch, so as to which the voltage difference of the grid of first switch and the source electrode of first switch is stablized The boost value of charge pump;And first voltage selection circuit is after the voltage of the drain electrode of first switch is pulled down to ground by pull-down circuit, Reckling in the voltage of the drain electrode of the voltage of the source electrode of first switch and first switch is transferred to the substrate of first switch, from And first switch can be made to remain disconnection.By charge pump instead of Zener diode in the utility model, due to electricity Lotus pump is made of capacitor and switch, and the requirement of capacitor and switch to manufacture craft is lower than Zener diode, therefore, can reduce Requirement of the analog switching circuit to manufacture craft, conducive to the realization of analog switching circuit.
Detailed description of the invention
In order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only It is the embodiments of the present invention, for those of ordinary skill in the art, without creative efforts, also Other attached drawings can be obtained according to the attached drawing of offer.
Fig. 1 is a kind of existing structural schematic diagram of analog switching circuit;
Fig. 2 is a kind of structural schematic diagram of analog switching circuit provided by the embodiment of the utility model;
Fig. 3 is the structural schematic diagram of another analog switching circuit provided by the embodiment of the utility model;
Fig. 4 is the structural schematic diagram of another analog switching circuit provided by the embodiment of the utility model;
Fig. 5 is the structural schematic diagram of another analog switching circuit provided by the embodiment of the utility model;
Fig. 6 is a kind of structural schematic diagram of charge pump provided by the embodiment of the utility model.
Specific embodiment
It is the core concept of the utility model above, to enable the above objects, features, and advantages of the utility model more Add and become apparent, the following will be combined with the drawings in the embodiments of the present invention, to the technical scheme in the embodiment of the utility model It is clearly and completely described, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than complete The embodiment in portion.Based on the embodiments of the present invention, those of ordinary skill in the art are not before making creative work Every other embodiment obtained is put, is fallen within the protection scope of the utility model.
The utility model embodiment provides a kind of analog switching circuit, as shown in Fig. 2, opening including charge pump 20, first Close M1, the first bleeder circuit 21, first voltage selection circuit 22 and pull-down circuit 23.It should be noted that the utility model is real Applying the first switch M1 in example is analog switch.When first switch M1 conducting when, by the input signal Vin of source S 1 conduct to Drain D 1 is output end vo ut.
As shown in Fig. 2, the input terminal of charge pump 20 is electrically connected with the substrate PW1 of first switch M1;The first of charge pump 20 Output end is electrically connected with the grid G 1 of first switch M1.Charge pump 20 is used in the first control letter for receiving control terminal PD output After number, control voltage is generated according to the voltage of the substrate PW1 of first switch M1, and first switch M1 is controlled by control voltage and is led It is logical, after the second control signal for receiving control terminal PD output, stop exporting the control voltage, it is disconnected to control first switch M1 It opens.
The first input end of first bleeder circuit 21 is electrically connected with the source S 1 of first switch M1, the first bleeder circuit 21 Second input terminal is electrically connected with the drain D 1 of first switch M1, the output end of the first bleeder circuit 21 and the substrate of first switch M1 PW1 electrical connection, the first bleeder circuit 21 are used to provide first to the substrate PW1 of first switch M1 in first switch M1 conducting Voltage, the sum of the voltage of source S 1 of the first voltage equal to first switch M1 and first voltage difference, first voltage difference is equal to first The half of voltage difference between the source S 1 of switch M1 and the drain D 1 of first switch M1.
The input terminal of pull-down circuit 23 is electrically connected with the drain D 1 of first switch M1, the output end of pull-down circuit 23 and ground connection GND electrical connection is held, pull-down circuit 23 is used for after the second control signal for receiving control terminal PD output, by first switch M1's The voltage of drain D 1 pulls down to ground.
The first input end of first voltage selection circuit 22 is electrically connected with the source S 1 of first switch M1, first voltage selection Second input terminal of circuit 22 is electrically connected with the drain D 1 of first switch M1, the output end of first voltage selection circuit 22 and first The substrate PW1 of switch M1 is electrically connected, and first voltage selection circuit 22 is used for the drain D 1 of first switch M1 in pull-down circuit 23 Voltage pull down to ground after, by the minimum in the voltage of the drain D 1 of the voltage of the source S 1 of first switch M1 and first switch M1 Person is transferred to the substrate PW1 of first switch M1.
Since charge pump 20 can be according to lesser input voltage VPWGenerate biggish control voltage VG, such as control voltage VG =VPW+VDD, VDDIt therefore can be by controlling voltage V for the steady state value that charge pump 20 providesGControl first switch M1 conducting and It disconnects, and then Zener diode can be substituted by charge pump 20.Since charge pump 20 is made of capacitor and switch, and capacitor and The manufacture craft of switch is simpler than Zener diode, therefore, can reduce requirement of the analog switching circuit to manufacture craft.
Also, since during first switch M1 conducting, the first voltage that the first bleeder circuit 21 provides is equal to the The voltage V of the source S 1 of one switch M1INThe sum of with first voltage difference, i.e. VPWEqual to VINAnd VDSThe sum of/2, since analog switch is The conduction impedance of first switch M1 is smaller, therefore, first voltage difference VDS/ 2 can be ignored, and therefore, first voltage is equal to the The voltage V of the source S 1 of one switch M1IN, at this point, VPW=VIN+VDD, so as to which the grid G 1 of first switch M1 and first are opened Close the stable boost value V in charge pump 20 of voltage difference of the source S 1 of M1DD, and then can guarantee that first switch M1 stablizes and open.
And the voltage of the drain D 1 of first switch M1 is pulled down to ground V in pull-down circuit 23 by first voltage selection circuit 22GND Afterwards, the reckling in the voltage of the drain D 1 of the voltage of the source S 1 of first switch M1 and first switch M1 first is transferred to open The substrate PW1 for closing M1, i.e., as the voltage of source S 1 such as larger than ground voltage VGNDWhen, first voltage selection circuit 22 can be by VGNDIt passes Substrate PW1 is transported to, when the voltage such as negative voltage of source S 1 is less than ground voltage VGNDWhen, first voltage selection circuit 22 can be by source The voltage transmission of pole S1 is to substrate PW1, so that first switch M1 remains disconnection.
In the utility model embodiment, in order to improve the isolation of analog switching circuit, avoid input signal Vin to output The interference for holding Vout, as shown in figure 3, analog switching circuit further includes second switch M2, the second bleeder circuit 24 and second voltage Selection circuit 25.Wherein, second switch M2 is analog switch, the source S 2 of second switch M2 and 1 electricity of drain D of first switch M1 Connection, the drain D 2 of second switch M2 are the output end vo ut of analog switching circuit.
As shown in figure 3, the first output end of charge pump 20 is electrically connected with the grid G 2 of second switch M2;Charge pump 20 is used for After the first control signal for receiving control terminal PD output, second switch M2 conducting is controlled by control voltage, is being received After the second control signal of control terminal PD output, stop output control voltage, control second switch M2 is disconnected.
Second bleeder circuit 24 is used in second switch M2 conducting, provides third electricity to the substrate PW2 of second switch M2 Pressure, the sum of the voltage of source S 2 of the tertiary voltage equal to second switch M2 and second voltage difference, second voltage difference are equal to second and open Close the half of the voltage difference between the source S 2 of M2 and the drain D 2 of second switch M2.
Pull-down circuit 23 is also used to after the second control signal for receiving control terminal PD output, by the source of second switch M2 The voltage of pole S2 pulls down to ground.Second voltage selection circuit 25 is used for the electricity of the source S 2 of second switch M2 in pull-down circuit 23 After pressure pulls down to ground, the reckling in the voltage of the drain D 2 of the voltage of the source S 2 of second switch M2 and second switch M2 is passed It is defeated by the substrate PW2 of second switch M2.
Optionally, as shown in figure 4, the first bleeder circuit 21 includes the first transistor M3 and second transistor M4;First electricity Pressing selection circuit 22 includes third transistor M5 and the 4th transistor M6.
The substrate of the first transistor M3 is electrically connected with the substrate PW1 of first switch M1, the grid of the first transistor M3 and The grid G 1 of one switch M1 is electrically connected, and the drain electrode of the first transistor M3 is electrically connected with the source S 2 of first switch M1, first crystal The source electrode of pipe M3 and the substrate electrical connection of the first transistor M3.The substrate of second transistor M4 and the substrate PW1 of first switch M1 Electrical connection, the grid of second transistor M4 are electrically connected with the grid G 1 of first switch M1, the drain electrode of second transistor M4 and first The drain D 1 of switch M1 is electrically connected, the source electrode of second transistor M4 and the substrate electrical connection of second transistor M4.
The substrate of third transistor M5 is electrically connected with the substrate PW1 of first switch M1, the grid of third transistor M5 and The drain D 1 of one switch M1 is electrically connected, and the drain electrode of third transistor M5 is electrically connected with the source S 1 of first switch M1, third crystal The source electrode of pipe M5 and the substrate electrical connection of third transistor M5;The substrate of 4th transistor M6 and the substrate PW1 of first switch M1 Electrical connection, the grid of the 4th transistor M6 are electrically connected with the source S 1 of first switch M1, the drain electrode and first of the 4th transistor M6 The drain D 1 of switch M1 is electrically connected, the source electrode of the 4th transistor M6 and the substrate electrical connection of the 4th transistor M6.
When first switch M1 conducting, the first transistor M3 and second transistor M4 can be also connected, at this point, the first transistor M3 and second transistor M4 play the role of partial pressure, so that the voltage V of substrate PW1PW=VIN+VDS/ 2, due to first voltage difference VDS/2 It can be ignored, therefore, the voltage V of source S 1 of the first voltage equal to first switch M1IN, at this point, VPW=VIN+VDD, thus The voltage difference of the grid G 1 of first switch M1 and the source S 1 of first switch M1 can be stablized to the boost value V in charge pump 20DD, And then it can guarantee that first switch M1 stablizes and open.
When the voltage of drain D 1 pulled down to i.e. VGNDAfterwards, when the voltage of source S 1 is positive voltage, the voltage of source S 1 Greater than the voltage of drain D 1, at this point, the 4th transistor M6 is connected, the voltage V of substrate PW1PW=VGND.Due to the voltage of drain D 1 While pulleding down to ground, charge pump 20 no longer works, that is, stops exporting the control voltage, therefore, VG=VGND, at this point, first Switch M1 can be remained open persistently.When the voltage of source S 1 is negative voltage, the voltage of source S 1 is less than the voltage of drain D 1, this When, third transistor M5 conducting, the voltage V of substrate PW1PW=VIN.While pulleding down to ground due to the voltage of drain D 1, electricity Lotus pump 20 no longer works, that is, stops exporting the control voltage, therefore, VG=VIN, due to VINFor negative voltage, therefore, first switch M1 can be remained open persistently.
Equally, as shown in figure 5, the second bleeder circuit 24 includes the 5th transistor M7 and the 6th transistor M8;Second voltage Selection circuit 25 includes the 7th transistor M9 and the 8th transistor M10.
The substrate of 5th transistor M7 is electrically connected with the substrate PW2 of second switch M2, the grid of the 5th transistor M7 and The grid G 2 of two switch M2 is electrically connected, and the drain electrode of the 5th transistor M7 is electrically connected with the source S 2 of second switch M2, the 5th crystal The substrate electrical connection of the source electrode of pipe M7 and the 5th transistor M7;
The substrate of 6th transistor M8 is electrically connected with the substrate PW2 of second switch M2, the grid of the 6th transistor M8 and The grid G 2 of two switch M2 is electrically connected, and the drain electrode of the 6th transistor M8 is electrically connected with the drain D 2 of second switch M2, the 6th crystal The substrate electrical connection of the source electrode of pipe M8 and the 6th transistor M8.
The substrate of 7th transistor M9 is electrically connected with the substrate PW2 of second switch M2, the grid of the 7th transistor M9 and The drain D 2 of two switch M2 is electrically connected, and the drain electrode of the 7th transistor M9 is electrically connected with the source S 2 of second switch M2, the 7th crystal The substrate electrical connection of the source electrode of pipe M9 and the 7th transistor M9;
The substrate of 8th transistor M10 is electrically connected with the substrate PW2 of second switch M2, the grid of the 8th transistor M10 with The source S 2 of second switch M2 is electrically connected, and the drain electrode of the 8th transistor M10 is electrically connected with the drain D 2 of second switch M2, and the 8th is brilliant The source electrode of body pipe M10 and the substrate electrical connection of the 8th transistor M10.
Wherein, the course of work of the second bleeder circuit 24 is identical as the course of work of the first bleeder circuit 21, second voltage Selection circuit 25 is identical as the course of work of first voltage selection circuit 22, and details are not described herein.
In any of the above-described embodiment, as shown in Figure 4 and Figure 5, pull-down circuit 23 includes the 9th transistor M11;Described The grid of nine transistor M11 is electrically connected with the control terminal PD, the source electrode and the first switch M1 of the 9th transistor M11 Drain D 1 and the source S 2 of second switch M2 be electrically connected, the drain electrode of the 9th transistor M11 is electrically connected with ground terminal GND, The substrate of the 9th transistor M11 is electrically connected with the second output terminal GS of the charge pump 20.
As shown in fig. 6, the charge pump 20 in the utility model embodiment includes the tenth transistor M12 to the 20th transistor M22, first capacitor C1 and the second capacitor C2.
The grid of tenth transistor M12 is electrically connected with the drain electrode of the 11st transistor M13, the source electrode of the tenth transistor M12 It being electrically connected with the input terminal of charge pump, the drain electrode of the tenth transistor M12 is electrically connected with the grid of the 11st transistor M13, and the tenth The source electrode of one transistor M13 is electrically connected with the input terminal of charge pump;
The drain electrode of tenth transistor M12 is also electrically connected with the first end of first capacitor, the second end of first capacitor and first Signal end electrical connection;The drain electrode of 11st transistor M13 is electrically connected with the first end of the second capacitor, the second end of the second capacitor with The electrical connection of second signal end;
The source electrode of tenth two-transistor M14 is electrically connected with the drain electrode of the tenth transistor M12, the leakage of the tenth two-transistor M14 Pole is electrically connected with the output end of charge pump, and the grid of the tenth two-transistor M14 is electrically connected with the source electrode of the 13rd transistor M15, The grid of 13rd transistor M15 is electrically connected with the source electrode of the tenth two-transistor M14, the drain electrode of the 13rd transistor M15 and electricity The output end electrical connection of lotus pump, the substrate of the 13rd transistor M15 and the substrate and the 14th transistor of the tenth two-transistor M14 The source electrode of M16 is electrically connected;
The drain electrode of 14th transistor M16 is electrically connected with the output end of charge pump, the grid of the 14th transistor M16 and The drain electrode of 15 transistor M17 is electrically connected, and the source electrode of the 15th transistor M17 is electrically connected with the source electrode of the 14th transistor M16, The grid of 15th transistor M17 is electrically connected with the drain electrode of the 14th transistor M16;
The grid of 16th transistor M18 is electrically connected with the drain electrode of the 17th transistor M19, the 17th transistor M19's Grid is electrically connected with the drain electrode of the 16th transistor M18, and the drain electrode of the 16th transistor M18 and the input terminal of charge pump are electrically connected It connects, the drain electrode of the 17th transistor M19 is electrically connected with ground terminal, the source electrode of the 16th transistor M18 and the 17th transistor M19 It is electrically connected with the source electrode of the 18th transistor M20;
The source electrode of 19th transistor M21 and the 20th transistor M22 is electrically connected with the source electrode of the 19th transistor M21, The grid of 18th transistor M20, the 19th transistor M21 and the 20th transistor M22 are electrically connected with control terminal, and the 18th is brilliant The drain electrode of body pipe M20 is electrically connected with the first end of first capacitor, the drain electrode and the first end of the second capacitor of the 19th transistor M21 Electrical connection, the drain electrode of the 20th transistor M22 are electrically connected with the output end of charge pump.
It should be noted that the tenth two-transistor M14 to the 15th transistor M17 is PMOS transistor, first switch M1 It is NMOS transistor to the 11st transistor M13 and the 16th transistor M18 to the 20th transistor M22.
After control terminal PD exports low level, the 18th transistor M20, the 19th transistor M21 and the 20th transistor M22 is disconnected, and charge pump 20 is in running order.In the process, if CLK=0, CLKN=VDD, then the 11st transistor M13 and Tenth two-transistor M14 conducting, B point are charged to VPW, A point is charged to VPW+VDD, the control voltage V of charge pump 20G=VPW+ VDD;If CLK=VDD, CLKN=0, the tenth transistor M12 and the 13rd transistor M15 conducting, B point is charged to VPW+VDD, A point It is charged to VPW, the control voltage V of charge pump 20G=VPW+VDD.Charge pump 20 is by control voltage VGIt is transmitted to first switch M1 After the grid of second switch M2, first switch M1 and second switch M2 conducting is controlled.
During first switch M1 and second switch M2 is connected, the first transistor M3 and second transistor M4 conducting, 5th transistor M7 and the 6th transistor M8 conducting, the voltage difference between first switch M1 grid G 1 and source S 1 is stablized VDD stablizes the voltage difference between the grid G 2 and source S 2 of second switch M2 in VDD.
After control terminal PD exports high level, the 18th transistor M20, the 19th transistor M21 and the 20th transistor The current potential of A point, B point and G point is pulled down to ground by M22 conducting, so that the 12nd switch M12 to the 13rd transistor M15 is disconnected It opens, so that charge pump 20 is in off position, so that first switch M1 and second switch M2 is disconnected.Meanwhile control terminal The high level of PD output can make the 9th transistor M11 be connected, thus by the source of the drain electrode of first switch M1 and second switch M2 The voltage of pole S2 pulls down to ground.
It should be noted that working as the voltage V of substrate PW1PWGreater than VGNDWhen, the 17th transistor M19 conducting, by VGNDTransmitting To the end GS, allow the 18th transistor M20, the 19th transistor M21 and the 20th transistor M22 by A point, B point and G point Current potential pull down to ground VGND.Equally, work as VPWLess than VGNDWhen, the 16th transistor M181 conducting, by VPWIt is transferred to the end GS, is made The 18th transistor M20, the 19th transistor M21 and the 20th transistor M22 can will be under the current potentials of A point, B point and G point It draws than ground VGNDMore low potential.
It should also be noted that, working as VGGreater than VGNDWhen, the 14th transistor M16 conducting, by VGIt is transferred to the 12nd crystal The substrate of pipe M14 and the 13rd transistor M15, work as VGLess than VGNDWhen, the 15th transistor M17 conducting, by VGNDIt is transferred to The substrate of ten two-transistor M14 and the 13rd transistor M15, the i.e. substrate of the tenth two-transistor M14 and the 13rd transistor M15 Voltage is consistently equal to max (VG, VGND), it thereby may be ensured that under any circumstance, the tenth two-transistor M14 and the 13rd crystal The parasitic body diode of pipe M15 all will not forward conduction, and then avoid electric leakage or even burn the risk of metal-oxide-semiconductor.
Analog switching circuit provided by the utility model, by charge pump instead of Zener diode, due to charge pump by Capacitor and switch composition, and the requirement of capacitor and switch to manufacture craft is lower than Zener diode, therefore, can reduce simulation and open Requirement of the powered-down road to manufacture craft.Also, made in the utility model by concatenated first switch M1 and second switch M2 Input signal Vin is not easy to be coupled to output end vo ut, so that the isolation of analog switching circuit is improved, so that simulation is opened Powered-down road can be applied to the certain pairs of higher occasions of insulated degree requirement.
Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with other The difference of embodiment, the same or similar parts in each embodiment may refer to each other.To the upper of the disclosed embodiments It states bright, can be realized professional and technical personnel in the field or using the utility model.Various modifications to these embodiments pair It will be apparent for those skilled in the art, the general principles defined herein can not depart from this reality In the case where with novel spirit or scope, realize in other embodiments.Therefore, the utility model is not intended to be limited to this These embodiments shown in text, and it is to fit to the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a kind of analog switching circuit, which is characterized in that including charge pump, first switch, the first bleeder circuit, first voltage choosing Select circuit and pull-down circuit;
The substrate electrical connection of the input terminal of the charge pump and the first switch;First output end of the charge pump with it is described The grid of first switch is electrically connected;The charge pump is used for after the first control signal for receiving control terminal output, according to institute The voltage for stating the substrate of first switch generates control voltage, and controls the first switch by the control voltage and be connected, After the second control signal for receiving the control terminal output, stop exporting the control voltage, to control the first switch It disconnects;
First bleeder circuit is used in first switch conducting, and the substrate of Xiang Suoshu first switch provides the first electricity Pressure, the first voltage are equal to the sum of voltage and first voltage difference of the source electrode of the first switch, described first voltage difference etc. The half of voltage difference between the source electrode of the first switch and the drain electrode of the first switch;
The pull-down circuit is used for after the second control signal for receiving the control terminal output, by the leakage of the first switch The voltage of pole pulls down to ground;
The first voltage selection circuit is used to pull down to ground for the voltage of the drain electrode of the first switch in the pull-down circuit Afterwards, the reckling in the voltage of the drain electrode of the voltage of the source electrode of the first switch and the first switch is transferred to described The substrate of one switch.
2. circuit according to claim 1, which is characterized in that further include second switch, the second bleeder circuit and the second electricity Press selection circuit;The source electrode of the second switch is electrically connected with the drain electrode of the first switch;
First output end of the charge pump is electrically connected with the grid of the second switch;The charge pump is used for receiving After the first control signal for stating control terminal output, the second switch is controlled by the control voltage and is connected, receiving After the second control signal for stating control terminal output, stop exporting the control voltage, be disconnected with controlling the second switch;
Second bleeder circuit is used in second switch conducting, and the substrate of Xiang Suoshu second switch provides third electricity Pressure, the tertiary voltage are equal to the sum of voltage and second voltage difference of the source electrode of the second switch, described second voltage difference etc. The half of voltage difference between the drain electrode of the source electrode and the second switch of the second switch;
The pull-down circuit is also used to after the second control signal for receiving the control terminal output, by the second switch The voltage of source electrode pulls down to ground;
The second voltage selection circuit is used to pull down to ground for the voltage of the source electrode of the second switch in the pull-down circuit Afterwards, the reckling in the voltage of the drain electrode of the voltage of the source electrode of the second switch and the second switch is transferred to described The substrate of two switches.
3. circuit according to claim 1 or 2, which is characterized in that the first bleeder circuit includes the first transistor and second Transistor;
The substrate electrical connection of the substrate of the first transistor and the first switch, the grid of the first transistor with it is described The grid of first switch is electrically connected, and the drain electrode of the first transistor is electrically connected with the source electrode of the first switch, and described first The substrate electrical connection of the source electrode of transistor and the first transistor;
The substrate electrical connection of the substrate of the second transistor and the first switch, the grid of the second transistor with it is described The grid of first switch is electrically connected, and the drain electrode of the second transistor is electrically connected with the drain electrode of the first switch, and described second The substrate electrical connection of the source electrode of transistor and the second transistor.
4. circuit according to claim 1 or 2, which is characterized in that the first voltage selection circuit includes third crystal Pipe and the 4th transistor;
The substrate electrical connection of the substrate of the third transistor and the first switch, the grid of the third transistor with it is described The drain electrode of first switch is electrically connected, and the drain electrode of the third transistor is electrically connected with the source electrode of the first switch, the third The substrate electrical connection of the source electrode of transistor and the third transistor;
The substrate electrical connection of the substrate of 4th transistor and the first switch, the grid of the 4th transistor with it is described The source electrode of first switch is electrically connected, and the drain electrode of the 4th transistor is electrically connected with the drain electrode of the first switch, and the described 4th The substrate electrical connection of the source electrode of transistor and the 4th transistor.
5. circuit according to claim 2, which is characterized in that the second bleeder circuit includes the 5th transistor and the 6th crystal Pipe;
The substrate electrical connection of the substrate of 5th transistor and the second switch, the grid of the 5th transistor with it is described The grid of second switch is electrically connected, and the drain electrode of the 5th transistor is electrically connected with the source electrode of the second switch, and the described 5th The substrate electrical connection of the source electrode of transistor and the 5th transistor;
The substrate electrical connection of the substrate of 6th transistor and the second switch, the grid of the 6th transistor with it is described The grid of second switch is electrically connected, and the drain electrode of the 6th transistor is electrically connected with the drain electrode of the second switch, and the described 6th The substrate electrical connection of the source electrode of transistor and the 6th transistor.
6. circuit according to claim 2, which is characterized in that the second voltage selection circuit include the 7th transistor and 8th transistor;
The substrate electrical connection of the substrate of 7th transistor and the second switch, the grid of the 7th transistor with it is described The drain electrode of second switch is electrically connected, and the drain electrode of the 7th transistor is electrically connected with the source electrode of the second switch, and the described 7th The substrate electrical connection of the source electrode of transistor and the 7th transistor;
The substrate electrical connection of the substrate of 8th transistor and the second switch, the grid of the 8th transistor with it is described The source electrode of second switch is electrically connected, and the drain electrode of the 8th transistor is electrically connected with the drain electrode of the second switch, and the described 8th The substrate electrical connection of the source electrode of transistor and the 8th transistor.
7. circuit according to claim 1, which is characterized in that the pull-down circuit includes the 9th transistor;Described 9th The grid of transistor is electrically connected with the control terminal, the source electrode of the 9th transistor and the drain electrode and second of the first switch The source electrode of switch is electrically connected, and the drain electrode of the 9th transistor is electrically connected with ground terminal, the substrate of the 9th transistor and institute State the second output terminal electrical connection of charge pump.
8. circuit according to claim 1, which is characterized in that the charge pump includes the tenth transistor, the 11st crystal Pipe, the tenth two-transistor, the 13rd transistor, the 14th transistor, the 15th transistor, the 16th transistor, the 17th crystalline substance Body pipe, the 18th transistor, the 19th transistor, the 20th transistor, first capacitor and the second capacitor;
The grid of tenth transistor is electrically connected with the drain electrode of the 11st transistor, the source electrode of the tenth transistor with The input terminal of the charge pump is electrically connected, and the drain electrode of the tenth transistor is electrically connected with the grid of the 11st transistor, The source electrode of 11st transistor is electrically connected with the input terminal of the charge pump;
The drain electrode of tenth transistor is also electrically connected with the first end of the first capacitor, the second end of the first capacitor with The electrical connection of first signal end;The drain electrode of 11st transistor is electrically connected with the first end of the second capacitor, second capacitor Second end be electrically connected with second signal end;
The source electrode of tenth two-transistor is electrically connected with the drain electrode of the tenth transistor, the drain electrode of the tenth two-transistor It is electrically connected with the output end of the charge pump, the source electrode of the grid and the 13rd transistor of the tenth two-transistor is electrically connected It connects, the grid of the 13rd transistor is electrically connected with the source electrode of the tenth two-transistor, the leakage of the 13rd transistor Pole is electrically connected with the output end of the charge pump, the substrate of the substrate of the 13rd transistor and the tenth two-transistor with The source electrode of 14th transistor is electrically connected;
The drain electrode of 14th transistor is electrically connected with the output end of the charge pump, the grid of the 14th transistor with The drain electrode of 15th transistor is electrically connected, the source electrode of the 15th transistor and the source electrode electricity of the 14th transistor Connection, the grid of the 15th transistor are electrically connected with the drain electrode of the 14th transistor;
The grid of 16th transistor is electrically connected with the drain electrode of the 17th transistor, the grid of the 17th transistor Pole is electrically connected with the drain electrode of the 16th transistor, the drain electrode of the 16th transistor and the input terminal electricity of the charge pump Connection, the drain electrode of the 17th transistor are electrically connected with ground terminal, the 16th transistor and the 17th transistor Source electrode be electrically connected with the source electrode of the 18th transistor;
The source electrode of 19th transistor and the 20th transistor is electrically connected with the source electrode of the 19th transistor, institute The grid for stating the 18th transistor, the 19th transistor and the 20th transistor is electrically connected with the control terminal, institute The drain electrode for stating the 18th transistor is electrically connected with the first end of the first capacitor, the drain electrode of the 19th transistor with it is described The first end of second capacitor is electrically connected, and the drain electrode of the 20th transistor is electrically connected with the output end of the charge pump.
9. circuit according to claim 8, which is characterized in that the tenth two-transistor to the 15th transistor is PMOS transistor, the tenth transistor, the 11st transistor, the 16th transistor to the 20th transistor are NMOS crystal Pipe.
10. circuit according to claim 2, which is characterized in that the first switch and the second switch are brilliant for NMOS Body pipe.
CN201822150934.XU 2018-12-20 2018-12-20 A kind of analog switching circuit Withdrawn - After Issue CN209184579U (en)

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Application Number Priority Date Filing Date Title
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109361384A (en) * 2018-12-20 2019-02-19 上海艾为电子技术股份有限公司 A kind of analog switching circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109361384A (en) * 2018-12-20 2019-02-19 上海艾为电子技术股份有限公司 A kind of analog switching circuit
CN109361384B (en) * 2018-12-20 2023-09-19 上海艾为电子技术股份有限公司 Analog switch circuit

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