CN204013456U - Switching circuit - Google Patents
Switching circuit Download PDFInfo
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- CN204013456U CN204013456U CN201420447399.3U CN201420447399U CN204013456U CN 204013456 U CN204013456 U CN 204013456U CN 201420447399 U CN201420447399 U CN 201420447399U CN 204013456 U CN204013456 U CN 204013456U
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- 230000001276 controlling effect Effects 0.000 claims abstract description 10
- 230000001105 regulatory effect Effects 0.000 claims abstract description 4
- 238000004904 shortening Methods 0.000 claims description 2
- 230000001133 acceleration Effects 0.000 claims 3
- 238000004804 winding Methods 0.000 abstract description 6
- 239000003990 capacitor Substances 0.000 description 17
- 238000010586 diagram Methods 0.000 description 11
- 238000000034 method Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
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Abstract
The utility model relates to a kind of switching circuit, comprises a MOSFET and for controlling the control circuit of a MOSFET conducting and cut-off.The one MOSFET is P channel-type MOSFET; Control circuit comprises the first control loop and the second control loop; The first control loop is connected with the grid of a MOSFET, for controlling the grid level of a MOSFET; The second control loop is connected between the grid and source electrode of a MOSFET, for regulating rise time and fall time of drain voltage of a MOSFET.Switching circuit of the present utility model need to be from the secondary reference voltage of drawing of winding, and therefore circuit volume is little, applied widely.
Description
Technical field
The application relates to a kind of Analogic Electronic Circuits, particularly a kind of switching circuit.
Background technology
Along with the use of novel switched power supply control IC, for meeting rise time (Rise time) requirement of specification definition in the past, the existing practice is to produce an A current potential (as shown in Figure 1) by the VCC winding of transformer, removes the switch N-MOSFET (Q156) of control inputs and outlet chamber.
Shown in Fig. 2 and Fig. 3, during for the Q156 turn-on and turn-off of the switching circuit of Fig. 1, capacitor C 163 discharge and recharge schematic diagram.
Shown in Figure 2, in the time of needs Q156 conducting, the VCC winding of transformer produces a stable A point current potential, and wherein A point current potential is higher than VOUT current potential.
Now suppose that A point current potential and VIN current potential all exist.In the time that control signal CON sets high (high) by low (low), Q101 conducting, Q161 is conducting again, A point current potential charges to capacitor C 163 and C153E via R166, until B point current potential equals A point current potential (supposition Q161 conduction voltage drop is 0V), Q156 saturation conduction, can change the length in charging interval by adjusting the resistance of R166 and the capacitance of C163 simultaneously, thereby realize the adjustment of the rise time (Tr) of VOUT current potential.
Shown in Figure 3, in the time that needs Q156 turn-offs, control signal CON sets low (low) by high (high), Q101 cut-off, Q161 ends again, and C163 current potential is by D161 and R169 electric discharge, until Q156 ends completely, the electric discharge speed of B point current potential can be changed by adjusting R169 resistance, the adjustment of the fall time (Fall time, Tf) of VOUT current potential can be realized.
The sequential chart of VIN, Vcon, B point current potential and A point current potential as shown in Figure 4.
But, along with the trend of Switching Power Supply miniaturization, meeting under the requirement of Switching Power Supply product performance, dwindle the size of transformer and simplify the structure of transformer and seem more and more important.And the switching circuit of Fig. 1-3 is due to need to be from the secondary A point current potential of drawing of VCC winding, cause the volume of whole switching circuit excessive, do not meet the nowadays trend of circuit miniaturization.
Utility model content
Provide hereinafter about brief overview of the present utility model, to the basic comprehension about some aspect of the present utility model is provided.Should be appreciated that this general introduction is not about exhaustive general introduction of the present utility model.It is not that intention is determined key of the present utility model or pith, neither be intended to limit scope of the present utility model.Its object is only that the form of simplifying provides some concept, using this as the preorder in greater detail of discussing after a while.
A main purpose of the present utility model is to provide a kind of switching circuit, can regulate rise time and fall time, and circuit size is little, applied widely.
According to an aspect of the present utility model, a kind of switching circuit, comprises a MOSFET and for controlling the control circuit of a described MOSFET conducting and cut-off; A described MOSFET is P channel-type MOSFET; Described control circuit comprises the first control loop and the second control loop; Described the first control loop is connected with the grid of a described MOSFET, for controlling the grid level of a described MOSFET; Described the second control loop is connected between the grid and source electrode of a described MOSFET, for regulating rise time and fall time of drain voltage of a described MOSFET.
Switching circuit of the present utility model need to be from the secondary reference voltage of drawing of winding, and therefore circuit volume is little, applied widely.
Brief description of the drawings
With reference to the explanation to the utility model embodiment below in conjunction with accompanying drawing, can understand more easily above and other objects, features and advantages of the present utility model.Parts in accompanying drawing are just in order to illustrate principle of the present utility model.In the accompanying drawings, same or similar technical characterictic or parts will adopt same or similar Reference numeral to represent.
Fig. 1 is the circuit diagram of existing a kind of switching circuit;
Fig. 2 is that the switching circuit of Fig. 1 is in the time of Q156 conducting, to the schematic diagram of C163 charging;
Fig. 3 is that the switching circuit of Fig. 1 is in the time that Q156 turn-offs, to the schematic diagram of C163 electric discharge;
Fig. 4 is the sequential chart of the switching circuit each point current potential of Fig. 1;
Fig. 5 is the circuit diagram of the switching circuit of the first execution mode of the present utility model;
Fig. 6 is that the switching circuit of Fig. 5 is in the time of Q156 conducting, to the schematic diagram of C163 charging;
Fig. 7 is that the switching circuit of Fig. 5 is in the time that Q156 turn-offs, to the schematic diagram of C163 electric discharge;
Fig. 8 is the sequential chart of the switching circuit each point current potential of Fig. 5;
Fig. 9 is the circuit diagram of the switching circuit of the second execution mode of the present utility model;
Figure 10 is that the switching circuit of Fig. 9 is in the time of Q156 conducting, to the schematic diagram of C163 charging;
Figure 11 is that the switching circuit of Fig. 9 is in the time that Q156 turn-offs, to the schematic diagram of C163 electric discharge;
Figure 12 is the sequential chart of the switching circuit each point current potential of Fig. 9.
Embodiment
Embodiment of the present utility model is described with reference to the accompanying drawings.The element of describing in an accompanying drawing of the present utility model or a kind of execution mode and feature can combine with element and feature shown in one or more other accompanying drawing or execution mode.It should be noted that for purposes of clarity, in accompanying drawing and explanation, omitted with the utility model irrelevant, expression and the description of parts known to persons of ordinary skill in the art and processing.
Shown in Figure 5, be the circuit diagram of the switching circuit of the first execution mode of the present utility model.
In the present embodiment, switching circuit comprises a MOSFET (Q156) and for controlling the control circuit of a MOSFET conducting and cut-off.
Wherein, a MOSFET is P channel-type MOSFET.
Control circuit comprises the first control loop 10 and the second control loop 20.The first control loop 10 is connected with the grid of a MOSFET (Q156), for controlling the grid level of a MOSFET (Q156).
The second control loop 20 is connected between the grid and source electrode of a MOSFET (Q156), for regulating rise time and fall time of drain voltage of a MOSFET (Q156).
As a kind of execution mode, the first control loop 10 can comprise the first capacitor C 162, the first resistance R 165, the second resistance R 169, the 3rd resistance R 167 and the 2nd MOSFETQ161.
Wherein, the grid of the first end of the first end of the first capacitor C 162, the first resistance R 165, the 2nd MOSFETQ161 is connected to and controls voltage end CON.
The second end of the first capacitor C 162, the second end of the first resistance R 165 are connected with the source electrode of the 2nd MOSFETQ161.
The drain electrode of the 2nd MOSFETQ161 is connected to the grid of a MOSFETQ156 through the second resistance R 169 and the 3rd resistance R 167 of series connection.
The second control loop 20 can comprise the second capacitor C 163 and the 4th resistance R 166.
Wherein, the first end of the second capacitor C 163 and the 4th resistance R 166 is connected to external power source VIN.The second end of the second capacitor C 163 and the 4th resistance R 166 is connected to the grid of a MOSFETQ156 through the 3rd resistance R 167.
Preferably, the switching circuit of present embodiment can also comprise the 3rd capacitor C 153E.The first end of the 3rd capacitor C 153E is connected to the drain electrode of a MOSFETQ156, the second end ground connection of the 3rd capacitor C 153E.
Shown in Fig. 6 and Fig. 7, in the time that control voltage end CON is low level (low), Q161 cut-off, B point current potential equals VIN current potential.
In the time that the voltage of control voltage end CON sets high (high) by low (low), Q161 conducting, B point current potential is via resistance R 169 is discharged over the ground, until B point current potential equals the dividing potential drop (supposition Q161 conduction voltage drop is 0V) of R166 and R169, Q156 conducting, can change length discharge time of B point current potential by adjusting the resistance of R166 and the capacitance adjustment of C163 simultaneously, thereby realize the Tr adjustment of VOUT current potential.
When the voltage of controlling voltage end CON is during by high (high) low (low), Q161 cut-off, VIN charges until equal VIN to B point current potential by R166, now Q156 cut-off, can change the discharge time of B point current potential by adjusting R166 resistance, the Tf that can realize VOUT current potential adjusts.
As shown in Figure 8, be the current potential sequential chart of each node in present embodiment switching circuit.In the time that the voltage of control voltage end CON becomes high, output voltage VO UT becomes high after Tr, and in the time that the voltage of control voltage end CON becomes low, output voltage VO UT becomes low after Tf.
Shown in Figure 9, be the switching circuit of the second execution mode of the present utility model.
Compared with the switching circuit of the first execution mode, the switching circuit of the second execution mode also comprises and accelerates discharge loop 30.
Accelerate discharge loop 30 and be connected between the first end of the 3rd resistance R 167 and the drain electrode of a MOSFETQ156, for the rise time Tr of the further drain voltage of shortening the one MOSFETQ156 and fall time Tf.
As a kind of execution mode, accelerate discharge loop 30 and can comprise the 5th resistance R 171, the 6th resistance R 173, the 7th resistance R 172, the first diode D150, the 4th capacitor C 156 and the 3rd MOSFETQ162;
Wherein, the 5th resistance R 171 is in parallel with the 4th capacitor C 156, the first end of the 5th resistance R 171 and the 4th capacitor C 156 and the source ground of the 3rd MOSFET Q162.
The second end of the 5th resistance R 171 and the 4th capacitor C 156, the grid of the 3rd MOSFETQ162 are connected with the positive pole of the first diode D150.
The drain electrode of the 3rd MOSFETQ162 is connected between the second resistance and the 3rd resistance.
The negative pole of the first diode D150 is connected to and controls voltage end CON1 through the 6th resistance R 173.
One end of of the 7th resistance R 172 is connected with the second end of the 4th capacitor C 156, and the second end of the 7th resistance R 172 is connected to the drain electrode of a MOSFETQ156.
As a kind of preferred version, the second control loop 20 can also comprise the second diode D161 and the 4th MOSFETQ163.
The plus earth of the second diode D161, the negative pole of the second diode D161 is connected to the drain electrode of the 4th MOSFETQ163.The drain electrode of the 4th MOSFET Q163 is also connected to the first end of the 4th resistance R 166.
The grid of the 4th MOSFET Q163 is connected to controls voltage end CON, and the source electrode of the 4th MOSFETQ163 is connected to external power source VIN.
Shown in Figure 10 and Figure 11, in the time that control voltage end CON is low level (low), Q161 cut-off, Q163 conducting (supposition Q163 conduction voltage drop is 0V), B point current potential equals VIN current potential.
In the time that the voltage of control voltage end CON sets high (high) by low (low), Q161 conducting, Q163 cut-off, B point current potential is via resistance R 169 is discharged over the ground, until B point current potential equals the dividing potential drop (supposition Q161 conduction voltage drop is 0V) of R166 and R169, Q156 conducting can change length discharge time of B point current potential by adjusting the resistance of R166 and the capacitance adjustment of C163 simultaneously, thereby realizes the Tr adjustment of VOUT current potential.VOUT current potential charges to capacitor C 156 by R172 when rising, in the time that C point current potential is greater than Q162 threshold voltage VTH, and Q162 saturation conduction (supposition Q162 conduction voltage drop is 0V), B point current potential is discharged to 0V by Q162.So, can accelerate the electric discharge that B is ordered, make VOUT reach rapidly impact point position.
When the voltage CON that controls voltage end is during by high (high) low (low), Q161 cut-off, Q163 conducting (supposition Q161 conduction voltage drop is 0V), VIN charges until equal VIN to B point current potential by R166, this switching tube Q156 cut-off, can change the discharge time of B point current potential by adjusting R166 resistance, the Tf that can realize VOUT current potential adjusts.
Adopt switching circuit of the present utility model, need to be from the secondary reference voltage of drawing of winding, therefore circuit volume is little, applied widely.
Above execution modes more of the present utility model are described in detail.As one of ordinary skill in the art can be understood, whole or any steps or the parts of method and apparatus of the present utility model, can be in the network of any computing equipment (comprising processor, storage medium etc.) or computing equipment, realized with hardware, firmware, software or their combination, this is that those of ordinary skill in the art use their basic programming skill just can realize in the situation that understanding content of the present utility model, therefore need not illustrate at this.
Should emphasize, term " comprises/comprises " existence that refers to feature, key element, step or assembly while use herein, but does not get rid of the existence of one or more further feature, key element, step or assembly or add.
Although described the utility model and advantage thereof in detail, be to be understood that in the case of not exceeding the spirit and scope of the present utility model that limited by appended claim and can carry out various changes, alternative and conversion.And the application's scope is not limited only to the specific embodiment of the described process of specification, equipment, means, method and step.One of ordinary skilled in the art will readily appreciate that from disclosure of the present utility model, can use and carries out with the essentially identical function of corresponding embodiment described herein or obtain process, equipment, means, method or step result essentially identical with it, that existing and will be developed future according to the utility model.Therefore, appended claim is intended to comprise such process, equipment, means, method or step in their scope.
Claims (8)
1. a switching circuit, comprises a MOSFET and for controlling the control circuit of a described MOSFET conducting and cut-off, it is characterized in that,
A described MOSFET is P channel-type MOSFET;
Described control circuit comprises the first control loop and the second control loop;
Described the first control loop is connected with the grid of a described MOSFET, for controlling the grid level of a described MOSFET;
Described the second control loop is connected between the grid and source electrode of a described MOSFET, for regulating rise time and fall time of drain voltage of a described MOSFET.
2. switching circuit according to claim 1, is characterized in that:
Described the first control loop comprises the first electric capacity, the first resistance, the second resistance, the 3rd resistance and the 2nd MOSFET;
Wherein,
The grid of the first end of described the first electric capacity, the first end of the first resistance, the 2nd MOSFET is connected to control voltage end;
The second end of described the first electric capacity, the second end of the first resistance are connected with the source electrode of described the 2nd MOSFET;
The drain electrode of described the 2nd MOSFET is connected to the grid of a described MOSFET through the second resistance and the 3rd resistance of series connection.
3. switching circuit according to claim 2, is characterized in that:
Described the second control loop comprises the second electric capacity and the 4th resistance;
Wherein,
The first end of described the second electric capacity and the 4th resistance is connected to external power source;
The second end of described the second electric capacity and the 4th resistance is connected to the grid of a described MOSFET through described the 3rd resistance.
4. according to the switching circuit described in claim 2 or 3 any one, it is characterized in that, also comprise the 3rd electric capacity;
The first end of described the 3rd electric capacity is connected to the drain electrode of a described MOSFET, the second end ground connection of described the 3rd electric capacity.
5. switching circuit according to claim 4, is characterized in that, also comprises acceleration discharge loop;
Described acceleration discharge loop is connected between the first end of described the 3rd resistance and the drain electrode of a described MOSFET, for further shortening rise time and the fall time of the drain voltage of a described MOSFET.
6. switching circuit according to claim 5, is characterized in that:
Described acceleration discharge loop comprises the 5th resistance, the 6th resistance, the 7th resistance, the first diode, the 4th electric capacity and the 3rd MOSFET;
Wherein,
Described the 5th resistance and described the 4th Capacitance parallel connection, described the 5th resistance and the first end of the 4th electric capacity and the source ground of described the 3rd MOSFET;
The grid of described the 5th resistance and the second end of the 4th electric capacity, described the 3rd MOSFET is connected with the positive pole of described the first diode;
The drain electrode of described the 3rd MOSFET is connected between the second resistance and the 3rd resistance;
The negative pole of described the first diode is connected to control voltage end through described the 6th resistance;
One end of of described the 7th resistance is connected with the second end of the 4th electric capacity, and the second end of the 7th resistance is connected to the drain electrode of a MOSFET.
7. switching circuit according to claim 6, is characterized in that:
Described the second control loop also comprises the second diode and the 4th MOSFET;
The plus earth of described the second diode, the negative pole of described the second diode is connected to the drain electrode of described the 4th MOSFET;
The drain electrode of described the 4th MOSFET is also connected to the first end of described the 4th resistance;
The grid of described the 4th MOSFET is connected to described control voltage end;
The source electrode of described the 4th MOSFET is connected to described external power source.
8. switching circuit according to claim 6, is characterized in that:
Described control voltage end is same control voltage end with controlling voltage end.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420447399.3U CN204013456U (en) | 2014-08-08 | 2014-08-08 | Switching circuit |
| TW103222603U TWM501051U (en) | 2014-08-08 | 2014-12-19 | Switch circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420447399.3U CN204013456U (en) | 2014-08-08 | 2014-08-08 | Switching circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204013456U true CN204013456U (en) | 2014-12-10 |
Family
ID=52053390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420447399.3U Active CN204013456U (en) | 2014-08-08 | 2014-08-08 | Switching circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN204013456U (en) |
| TW (1) | TWM501051U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107612534A (en) * | 2017-09-18 | 2018-01-19 | 深圳市沃特沃德股份有限公司 | On-off circuit and terminal device |
| CN110571917A (en) * | 2019-09-30 | 2019-12-13 | 华勤通讯技术有限公司 | Switching control circuit and electronic equipment |
-
2014
- 2014-08-08 CN CN201420447399.3U patent/CN204013456U/en active Active
- 2014-12-19 TW TW103222603U patent/TWM501051U/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107612534A (en) * | 2017-09-18 | 2018-01-19 | 深圳市沃特沃德股份有限公司 | On-off circuit and terminal device |
| CN110571917A (en) * | 2019-09-30 | 2019-12-13 | 华勤通讯技术有限公司 | Switching control circuit and electronic equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| TWM501051U (en) | 2015-05-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210120 Address after: 523290 Xincheng District, Shijie Town, Dongguan City, Guangdong province (Delta Industrial Zone) Patentee after: DELTA ELECTRONICS (DONGGUAN) Co.,Ltd. Address before: 523308 Xincheng District, Shijie Town, Dongguan City, Guangdong Province Patentee before: DELTA ELECTRONICS POWER (DONG GUAN) Co.,Ltd. |
|
| TR01 | Transfer of patent right |