CN202632145U - Low-dropout voltage regulator - Google Patents
Low-dropout voltage regulator Download PDFInfo
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- CN202632145U CN202632145U CN 201120541122 CN201120541122U CN202632145U CN 202632145 U CN202632145 U CN 202632145U CN 201120541122 CN201120541122 CN 201120541122 CN 201120541122 U CN201120541122 U CN 201120541122U CN 202632145 U CN202632145 U CN 202632145U
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Abstract
The utility model provides a low-dropout voltage regulator, which comprises a primary power tube, a branch circuit and an error amplifying circuit. The branch circuit samples the output voltage from the output end of the primary power tube to obtain a feedback voltage. The error amplifier controls the grid electrode of the primary power tube according to the feedback voltage and a reference voltage. The low-dropout voltage regulator further comprises a control circuit and a standby power tube. When the current on the primary power tube is larger than a set current threshold value, the control circuit enables the standby power tube so as to make the standby power tube supply currents to a load. Otherwise, the control circuit does not enable the standby power tube so as to make the standby power tube unable to supply currents to the load. By changing the effective areas and the effective widths of the power tubes according to a change in the load, then different current requirements in different load current conditions are satisfied. The using efficiency is increased. The excessively low efficiency problem due to excessively large leakage currents of the power tubes is also prevented.
Description
[technical field]
The utility model relates to field of power management, particularly relates to a kind of low difference voltage regulator.
[background technology]
SOC (SOC(system on a chip)) is the main direction of present digit chip development; In the increasing digital display circuit; Be integrated into power management chip (such as low difference voltage regulator) together in the single-chip with Digital Logic, formed a more complete SOC(system on a chip).
Fig. 1 shows a kind of circuit diagram of existing low difference voltage regulator 100.Said low difference voltage regulator 100 comprises reference voltage circuit 110, error amplifier 120, power tube MP, bleeder circuit 130, pull-up resistor RL and capacitor C L.Said reference voltage circuit 110 produces one not with the reference voltage V REF of temperature, technology and mains voltage variations; Bleeder circuit 130 comprises divider resistance R1 and the divider resistance R2 that is connected between output voltage VO UT and the ground; Its sampling and outputting voltage VOUT obtains feedback voltage V FB; Said error amplifier 120 benchmark voltage VREF and feedback voltage V FB; The grid voltage that is used to adjust power tube MP after the difference amplification with both is to guarantee that output voltage VO UT keeps proportional with said reference voltage V REF under different supply voltage VBAT and load current conditions.
Current digital circuit technology has carried out the transition to 0.18um, 0.13um or the 90nm technology of main flow, and reducing of device channel effective length makes the leakage current of device can not ignore.The leakage current of MOSFET (Metal Oxide Semiconductor Field Effect Transistor) increases along with reducing of its channel length, and the width along with raceway groove increases and increases simultaneously.For the low difference voltage regulator that is integrated in the digital display circuit, its function must satisfy in the scope that output voltage VO UT under the various load current conditions is setting.Two kinds of extreme cases of load current comprise: can extract minimum load current in the time of in the time of system's operate as normal, can extracting maximum load current and system standby.The area that increases power tube MP can guarantee when the load operate as normal, to provide maximum load current; When but system standby or low difference voltage regulator are unloaded; Because the leakage current that the grid area of power tube MP brings can make output voltage VO UT raise; Even the gate voltage that error amplifier 120 adjustment make power tube MP can not make output voltage VO UT get back in the voltage range of setting near supply voltage VBAT, whole like this backfeed loop will be in open-circuit condition.The traditional solution is the value that reduces the divider resistance in the bleeder circuit; Guarantee that at load current be under the no-load condition; The leakage current of power tube MP can be absorbed by divider resistance, but this has also increased the quiescent current of system simultaneously, has reduced the service efficiency of power supply.
Therefore, be necessary to propose a kind of improved technical scheme and solve the problems referred to above.
[utility model content]
The purpose of the utility model is to provide a kind of high-level efficiency low difference voltage regulator, and it can keep higher service efficiency under the situation of various loads.
To achieve these goals; The utility model proposes a kind of; It comprises first-selected power tube, bleeder circuit and error amplifying circuit; The sample output voltage of output terminal of said first-selected power tube of said bleeder circuit obtains feedback voltage, and said error amplifier is controlled the grid of said first-selected power tube according to a said feedback voltage and a reference voltage.Said low difference voltage regulator also comprises control circuit and non-firm power pipe; The electric current of said control circuit on first-selected power tube is when setting current threshold; Enable said non-firm power pipe so that it also provides electric current for load; Otherwise the said non-firm power pipe of disable is so that it can not provide electric current for load.
Further; Said low difference voltage regulator also includes the switch control tube; Said switch control tube is series between said non-firm power pipe and the power supply, and the electric current of said control circuit on first-selected power tube controlled the conducting of said switch control tube when setting current threshold; Otherwise, control said switch control tube and end.
Further; Said control circuit comprises current sample module and current comparing module; Said current sample module detects the electric current of said first-selected power tube; Said current comparing module compares the electric current on the said first-selected power tube with setting current threshold, the electric current on first-selected power tube is when setting current threshold, and the control end that outputs control signals to said switch control tube is to control the conducting of said switch control tube; Otherwise the control end that outputs control signals to said switch control tube ends to control said switch control tube.
Further again; Said current sample module is the mirror image power tube that constitutes mirror image circuit with said first-selected power tube; The drain electrode of a said mirrored transistor of input termination of said current comparing module; The drain electrode of the said first-selected power transistor of another input termination, the drain electrode of this first-selection power tube is its output terminal, the grid of the said switch control tube of its output termination.
Further again, the source class of said first-selected power tube connects power supply, and the source class of said non-firm power pipe connects said power supply through said open pipe control tube, and drain electrode connects the drain electrode of said first-selected power tube, and grid connects the grid of said first-selected power tube.
Further again; Said current comparing module comprises the 1st transistor, the 10th transistor, the 11st transistor, the 12nd transistor, the 13rd transistor, the 14th transistor, the 16th transistor; The 1st transistor and the 16th transistor series are between power supply and ground, and the 1st transistorized grid connects the grid of said first-selected power tube, and the 11st transistor and the 13rd transistor series are between the drain electrode and ground of said first-selected power tube; The 10th transistor and the 12nd transistor series are between the drain electrode and ground of mirrored transistor; The 10th transistor and the 11st transistorized gate interconnect, the 12nd transistor, the 13rd transistor and the 14th transistorized gate interconnect, the 14th transistorized source class ground connection; Drain electrode connects reference current, and the node between the 10th transistor and the 12nd transistor connects the grid of the 16th transistor M16.
Further, said bleeder circuit comprises output terminal and first divider resistance between the ground and second divider resistance that is series at said first-selected power tube, and the voltage of the intermediate node of first divider resistance and second divider resistance is said feedback voltage.
Further, said low difference voltage regulator also comprises output terminal and electric capacity between the ground and the pull-up resistor that is connected on first-selected power tube.
Compared with prior art; In the utility model according to the useful area of the change power tube of load; Thereby change the effective width of power tube; Thereby satisfy the electric current demand under the different loads current conditions, improved service efficiency, also avoid causing the low excessively problem of efficient owing to the leakage current of power tube is excessive.
[description of drawings]
In order to be illustrated more clearly in the technical scheme of the utility model embodiment; The accompanying drawing of required use is done to introduce simply in will describing embodiment below; Obviously, the accompanying drawing in describing below only is some embodiment of the utility model, for those of ordinary skills; Under the prerequisite of not paying creative work property, can also obtain other accompanying drawing according to these accompanying drawings.Wherein:
Fig. 1 is the circuit diagram of prior art mesolow difference voltage regulator; With
Fig. 2 is the high-level efficiency low difference voltage regulator circuit diagram in one embodiment in the utility model.
[embodiment]
For above-mentioned purpose, the feature and advantage that make the utility model can be more obviously understandable, the utility model is done further detailed explanation below in conjunction with accompanying drawing and embodiment.
Fig. 2 is high-level efficiency low difference voltage regulator 200 circuit diagram in one embodiment in the utility model.As shown in Figure 2, said low difference voltage regulator 200 comprises power tube M15 (also can be called as first-selected power tube), bleeder circuit 210, error amplifying circuit 220, is connected on the output terminal VOUT of power tube M15 and capacitor C L and the pull-up resistor RL between the ground VSS.
The source class of said power tube M 15 meets power supply VBAT, and grid connects the output terminal of said error amplifying circuit 220, and its drain electrode is the output terminal VOUT of said power tube M15.The output voltage of the output terminal of the said power tube M15 of said bleeder circuit 210 samplings, and obtain reflecting the feedback voltage V FB of said output voltage.Said error amplifying circuit 220 benchmark voltage VREF and feedback voltage V FB; The grid voltage that is used to adjust power tube M15 after the difference amplification with both is to guarantee that output voltage VO UT keeps preset proportion with said reference voltage V REF under different supply voltage VBAT and load current conditions.
In order to overcome the problem of low difference voltage regulator of the prior art, the low difference voltage regulator 200 in the utility model also includes control circuit 230, non-firm power pipe M4 and switch control tube M3.
The grid of said non-firm power pipe M4 connects the grid of power tube M15, and drain electrode connects the drain electrode of power tube M15, and source class meets power supply VBAT through said switch control tube M3.The drain electrode of the said power tube M15 of input termination of said control circuit 230, the grid of the said CS pipe of output termination M3.The electric current that said control circuit 230 detects on the said power tube M15 when setting current threshold, is then controlled said switch control tube M3 conducting at detected electric current, otherwise, then control said switch control tube M3 and end.When said switch control tube M3 conducting, said non-firm power pipe M4 is parallelly connected with said power tube M15, jointly for load provides electric current, has been equivalent to increase the useful area of power tube and effective channel width this moment.When said switch control tube M3 ends, cut off said non-firm power pipe M4, by the load of said power tube M15 independence electric current is provided, be equivalent to reduce the useful area and effective channel width of power tube.
Said control circuit 230 comprises current sample module 231 and current comparing module 232.Said current sample module 231 detects the electric current of said power tube M15, and said current comparing module 232 compares electric current on the said power tube and setting current threshold with the output control signal.Said current sample module is mirrored transistor M2, and the grid of this mirrored transistor M2 links to each other with the grid of power tube M15, and source class links to each other with power supply VBAT, and this mirrored transistor M2 and said power tube M15 form current mirror.The drain electrode A1 of a said mirrored transistor M2 of input termination of said current comparing module; The drain electrode VOUT of the said power transistor of another input termination; The electric current of this current comparing module on said power tube overturns when equaling to set current threshold, the grid (being control end) of its output terminals A 3 and said switch control tube M3.
Said current comparing module 232 comprises transistor M1, M10, M11, M12, M13, M14, M16, and said transistor M1 and M16 are connected between power supply VBAT and the ground VSS, and the grid of said transistor M1 connects the grid of said power tube M15.Said transistor M11 and M13 are connected between output terminal VOUT and the ground VSS; Said transistor M10 and M12 are connected between node A1 and the ground VSS; The gate interconnect of transistor M10 and M11; The gate interconnect of transistor M12, M13 and M13, the source class ground connection VSS of transistor M14, drain electrode meets reference current IB.Transistor M12, M13 and M14 constitute current mirror.Node A2 between transistor M10 and the M12 connects the grid of said transistor M16.
In the circuit that proposes, transistor M1 and M15 and M2 also constitute current mirror, when its current ratio that flows through relation is identical with its breadth length ratio proportionate relationship, and transistor M1, M2, the drain terminal voltage of M15 equates.Promptly work as I
M15=K*I
M2, when K is the ratio of breadth length ratio of transistor M15 and M2, VA1=VOUT.
The equilibrium state of said current comparing module is: I
M2=I
M12=IB, I
M15=K*I
M2=K*IB, wherein I
M2Be the electric current on the transistor M2, IM12 is the electric current on the transistor M12, and IM15 is the electric current on the transistor M15, at this moment VA1=VOUT.
When underload, i.e. Iout=I
M15During＜K*IB; VOUT＞VA1, the output terminals A 3 of said current comparing module is a high level, this moment, switch control tube M3 turn-offed; The useful power pipe of said low difference voltage regulator 200 is merely power tube M15; Under underload, reduce the useful area of power tube, can effectively reduce the leakage current of power tube, the short channel device that particularly applies to digital circuit is particularly effective.
When heavy duty, i.e. Iout=I
M15During＞K*IB; VOUT＜VA1; The output terminals A 3 of said current comparing module is a low level, switch control tube M3 conducting this moment, and the useful power pipe of said low difference voltage regulator 200 adds non-firm power pipe M4 for power tube M15; Increase the area of power tube, can provide load bigger electric current.
According to the useful area and the effective width of the change power tube of load, thereby satisfy the electric current demand under the different loads current conditions, improved service efficiency, also avoid causing the low excessively problem of efficient owing to the leakage current of power tube is excessive.Through reasonable reference electric current I B is set, the switching value of the weight load of initialization circuit accurately.This technology receives technological parameter and Influence of Temperature is smaller equally.
" connection " among this paper, " joining ", " being connected to " etc. relate to the speech of electric connection all can represent direct or indirect electric connection.
Above-mentioned explanation has fully disclosed the embodiment of the utility model.It is pointed out that any change that the technician that is familiar with this field does the embodiment of the utility model does not all break away from the scope of claims of the utility model.Correspondingly, the scope of the claim of the utility model also is not limited only to previous embodiment.
Claims (8)
1. low difference voltage regulator; It comprises first-selected power tube, bleeder circuit and error amplifying circuit; The sample output voltage of output terminal of said first-selected power tube of said bleeder circuit obtains feedback voltage; Said error amplifier is controlled the grid of said first-selected power tube according to a said feedback voltage and a reference voltage
It is characterized in that; Said low difference voltage regulator also comprises control circuit and non-firm power pipe; The electric current of said control circuit on first-selected power tube is when setting current threshold; Enable said non-firm power pipe so that its also for load provides electric current, otherwise the said non-firm power pipe of disable is so that it can not provide electric current for load.
2. low difference voltage regulator according to claim 1; It is characterized in that it also includes the switch control tube, said switch control tube is series between said non-firm power pipe and the power supply; The electric current of said control circuit on first-selected power tube is when setting current threshold; Control the conducting of said switch control tube, otherwise, control said switch control tube and end.
3. low difference voltage regulator according to claim 2; It is characterized in that; Said control circuit comprises current sample module and current comparing module, and said current sample module detects the electric current of said first-selected power tube, and said current comparing module compares electric current on the said first-selected power tube and setting current threshold; Electric current on first-selected power tube is when setting current threshold; The control end that outputs control signals to said switch control tube is controlling the conducting of said switch control tube, otherwise the control end that outputs control signals to said switch control tube ends to control said switch control tube.
4. low difference voltage regulator according to claim 3; It is characterized in that; Said current sample module is the mirror image power tube that constitutes mirror image circuit with said first-selected power tube, the drain electrode of a said mirrored transistor of input termination of said current comparing module, the drain electrode of the said first-selected power transistor of another input termination; The drain electrode of this first-selection power tube is its output terminal, the grid of the said switch control tube of its output termination.
5. low difference voltage regulator according to claim 4; It is characterized in that; The source class of said first-selected power tube connects power supply; The source class of said non-firm power pipe connects said power supply through said open pipe control tube, and drain electrode connects the drain electrode of said first-selected power tube, and grid connects the grid of said first-selected power tube.
6. low difference voltage regulator according to claim 5; It is characterized in that; Said current comparing module comprises the 1st transistor, the 10th transistor, the 11st transistor, the 12nd transistor, the 13rd transistor, the 14th transistor, the 16th transistor; The 1st transistor and the 16th transistor series are between power supply and ground, and the 1st transistorized grid connects the grid of said first-selected power tube, and the 11st transistor and the 13rd transistor series are between the drain electrode and ground of said first-selected power tube; The 10th transistor and the 12nd transistor series are between the drain electrode and ground of mirrored transistor; The 10th transistor and the 11st transistorized gate interconnect, the 12nd transistor, the 13rd transistor and the 14th transistorized gate interconnect, the 14th transistorized source class ground connection; Drain electrode connects reference current, and the node between the 10th transistor and the 12nd transistor connects the grid of the 16th transistor M16.
7. according to the arbitrary described low difference voltage regulator of claim 1-6; It is characterized in that; Said bleeder circuit comprises output terminal and first divider resistance between the ground and second divider resistance that is series at said first-selected power tube, and the voltage of the intermediate node of first divider resistance and second divider resistance is said feedback voltage.
8. according to the arbitrary described low difference voltage regulator of claim 1-6, it is characterized in that it also comprises output terminal and electric capacity between the ground and the pull-up resistor that is connected on first-selected power tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120541122 CN202632145U (en) | 2011-12-15 | 2011-12-15 | Low-dropout voltage regulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120541122 CN202632145U (en) | 2011-12-15 | 2011-12-15 | Low-dropout voltage regulator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202632145U true CN202632145U (en) | 2012-12-26 |
Family
ID=47385322
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201120541122 Withdrawn - After Issue CN202632145U (en) | 2011-12-15 | 2011-12-15 | Low-dropout voltage regulator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202632145U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103163925A (en) * | 2011-12-15 | 2013-06-19 | 无锡中星微电子有限公司 | High efficiency low drop-out voltage regulator |
| CN104569548A (en) * | 2014-12-30 | 2015-04-29 | 上海贝岭股份有限公司 | Line voltage detection circuit for switching power supply |
| CN106325344A (en) * | 2015-06-29 | 2017-01-11 | 展讯通信（上海）有限公司 | A low voltage difference voltage stabilizer circuit with an auxiliary circuit |
| CN108885474A (en) * | 2016-03-25 | 2018-11-23 | 松下知识产权经营株式会社 | Adjuster circuit |
| CN113672024A (en) * | 2021-07-21 | 2021-11-19 | 北京时代民芯科技有限公司 | Leakage current compensation circuit and method applied to low-power LDO (low dropout regulator) |
-
2011
- 2011-12-15 CN CN 201120541122 patent/CN202632145U/en not_active Withdrawn - After Issue
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103163925A (en) * | 2011-12-15 | 2013-06-19 | 无锡中星微电子有限公司 | High efficiency low drop-out voltage regulator |
| CN103163925B (en) * | 2011-12-15 | 2014-11-05 | 无锡中星微电子有限公司 | High efficiency low drop-out voltage regulator |
| CN104569548A (en) * | 2014-12-30 | 2015-04-29 | 上海贝岭股份有限公司 | Line voltage detection circuit for switching power supply |
| CN106325344A (en) * | 2015-06-29 | 2017-01-11 | 展讯通信（上海）有限公司 | A low voltage difference voltage stabilizer circuit with an auxiliary circuit |
| CN106325344B (en) * | 2015-06-29 | 2018-01-26 | 展讯通信（上海）有限公司 | Low-dropout regulator circuit with auxiliary circuit |
| CN108885474A (en) * | 2016-03-25 | 2018-11-23 | 松下知识产权经营株式会社 | Adjuster circuit |
| CN113672024A (en) * | 2021-07-21 | 2021-11-19 | 北京时代民芯科技有限公司 | Leakage current compensation circuit and method applied to low-power LDO (low dropout regulator) |
| CN113672024B (en) * | 2021-07-21 | 2022-11-01 | 北京时代民芯科技有限公司 | Leakage current compensation circuit and method applied to low-power LDO (low dropout regulator) |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20121226 Effective date of abandoning: 20141105 |
|
| RGAV | Abandon patent right to avoid regrant |