CN104238702A - Power supply circuit - Google Patents
Power supply circuit Download PDFInfo
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- CN104238702A CN104238702A CN201310225281.6A CN201310225281A CN104238702A CN 104238702 A CN104238702 A CN 104238702A CN 201310225281 A CN201310225281 A CN 201310225281A CN 104238702 A CN104238702 A CN 104238702A
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Abstract
The invention discloses a power supply circuit which comprises a voltage conversion circuit. The voltage conversion circuit comprises a PWM (Pulse-Width Modulation) controller and multiple transistor switches connected with the PWM controller; the power supply circuit further comprises a comparison circuit connected with the PWM controller; the comparison circuit compares a ripple voltage of an output voltage signal of the voltage conversion circuit with a preset threshold; if the peak value of the ripple voltage is smaller than the preset threshold, the comparison circuit outputs a first signal to the PWM controller, and the PWM controller reduces the frequency of switching the transistor switches; if the peak value of the ripple voltage is not less than the preset threshold, the comparison circuit outputs a second signal to the PWM controller, and the PWM controller increases the frequency of switching the transistor switches. The power supply circuit disclosed by the invention not only controls the size of the ripple voltage, but also reduces the switching consumption of the transistor switches.
Description
Technical field
The present invention relates to a kind of feed circuit, espespecially a kind of feed circuit for portable computer.
Background technology
The CPU of portable computer is powered by single-phase, two-phase or heterogeneous feed circuit usually, described feed circuit comprise a PWM(Pulse Width Modulation, width modulation) controller, transistor switch (as field effect transistor), inductance and electric capacity that at least one pair of is connected with described PWM controller, described PWM controller switches described transistor switch according to pwm signal, thus controls the size of output voltage.The output voltage of described feed circuit has ripple usually, in order to by the Maximum constraint of ripple voltage within the limits prescribed, can improve the switching frequency of described transistor switch, but the switching frequency improving transistor switch can cause the handoff loss of transistor switch to increase.
Summary of the invention
In view of above content, be necessary that providing a kind of can control ripple voltage within the limits prescribed and reduce the feed circuit of the handoff loss of transistor switch as far as possible.
A kind of feed circuit, comprise a voltage conversion circuit, described voltage conversion circuit comprises the transistor switch that a PWM controller and multiple and described controller are connected, described PWM controller controls the state switching described multiple transistor switch, described feed circuit also comprise a comparator circuit be connected with described PWM controller, the ripple voltage of the output voltage signal of described voltage conversion circuit and the threshold value preset compare by described comparator circuit, if the peak value of described ripple voltage is less than described default threshold value, described comparator circuit exports one first signal to described PWM controller, described PWM controller reduces the frequency switching described transistor switch, if the peak value of described ripple voltage is not less than described default threshold value, described comparator circuit exports a secondary signal to described PWM controller, and described PWM controller improves the frequency switching described transistor switch.
In one embodiment, described feed circuit also comprise a high-pass filtering circuit be connected with the voltage output end of described voltage conversion circuit, the flip-flop of the output voltage signal of described voltage conversion circuit filters out by described high-pass filtering circuit, obtains described ripple signal.
In one embodiment, described high-pass filtering circuit comprises one first resistance and one second electric capacity, and one end of described second electric capacity is connected with the voltage output end of described voltage conversion circuit, and the other end is connected with a first node; One end of described first resistance is connected with described first node.Other end ground connection, described high-pass filtering circuit exports described ripple voltage by described first node.
In one embodiment, described feed circuit also comprise an amplifying circuit, and described amplifying circuit is connected with described first node, and the ripple voltage exported by described high-pass filtering circuit carries out amplification process.
In one embodiment, described amplifying circuit includes one first transport and placing device, one second resistance and one the 3rd resistance, the positive input of described first transport and placing device is connected with described first node, and negative input is connected with one end of described second resistance, the other end ground connection of described second resistance; One end of described 3rd resistance is connected with a Section Point, and negative input and described second resistance of the other end and described first operational amplifier are connected; The output terminal of described first operational amplifier is connected with described Section Point; Described amplifying circuit exports the ripple voltage signal after amplifying by described Section Point.
In one embodiment, the voltage of described second resistance is R2, and the voltage of described 3rd resistance is R3, and described amplifying circuit is (R2+R3)/R2 to the multiple that described ripple voltage amplifies.
In one embodiment, described feed circuit also comprise a peak value checking circuit, and described peak value checking circuit exports the peak value of the ripple voltage amplified through described amplifying circuit to described comparator circuit.
In one embodiment, described peak value checking circuit comprises one second transport and placing device, a diode and one the 3rd electric capacity; The positive input of described second transport and placing device is connected with described Section Point, and negative input is connected with one the 3rd node; The negative pole of described diode is connected with described 3rd node, and positive pole is connected with the output terminal of described second transport and placing device; One end of described 3rd electric capacity is connected with described 3rd node, other end ground connection; Described peak value checking circuit exports the peak value of the ripple voltage after amplifying by described 3rd node.
In one embodiment, described comparator circuit comprises one the 3rd transport and placing device, and the negative input of described 3rd transport and placing device is connected with described 3rd node, and positive input connects a reference voltage, and the output terminal of described 3rd transport and placing device is connected with described PWM controller.
In one embodiment, described comparator circuit also comprises a transistor, one the 4th resistance and one the 5th resistance, the output terminal of described 3rd transport and placing device is connected with the grid of described transistor, the drain electrode of described transistor is connected with described 4th resistance one end, and the other end of described 4th resistance R is connected with one the 4th node; The source ground of described transistor; One end of described 5th resistance is connected with described 4th node, another termination one power supply signal; Described comparator circuit exports compare result signal to described PWM controller by described 4th node.
Compared with prior art, in above-mentioned feed circuit, the ripple voltage of the output voltage of voltage conversion circuit and the threshold value preset compare by described comparator circuit, if ripple voltage is less than default threshold value, then notify that described PWM controller reduces the frequency of switching transistor switch; If ripple voltage is not less than default threshold value, then notify that described PWM controller improves the frequency of switching transistor switch, take into account the size controlling ripple voltage and the handoff loss reducing transistor switch.
Accompanying drawing explanation
Fig. 1 is the comprising modules figure of a better embodiment of feed circuit of the present invention.
Fig. 2 is the physical circuit figure of feed circuit in Fig. 1.
Main element symbol description
| Voltage conversion circuit | 10 |
| High-pass filtering circuit | 20 |
| Amplifying circuit | 30 |
| Peak value checking circuit | 40 |
| Comparator circuit | 50 |
| PWM controller | 11 |
| The first transistor | Q1 |
| Transistor seconds | Q2 |
| Third transistor | Q3 |
| 4th transistor | Q4 |
| Inductance | L1 |
| First electric capacity | C1 |
| Second electric capacity | C2 |
| 3rd electric capacity | C3 |
| 4th electric capacity | C4 |
| First resistance | R1 |
| Second resistance | R2 |
| 3rd resistance | R3 |
| 4th resistance | R4 |
| 5th resistance | R5 |
| First transport and placing device | 31 |
| Second transport and placing device | 41 |
| 3rd transport and placing device | 51 |
| Diode | D1 |
Following embodiment will further illustrate the present invention in conjunction with above-mentioned accompanying drawing.
Embodiment
Refer to Fig. 1, a better embodiment of feed circuit of the present invention comprises voltage conversion circuit 10, high-pass filtering circuit 20, amplifying circuit 30, peak value checking circuit 40 and a comparator circuit 50.In one embodiment, described feed circuit for the mainboard of a portable computer, for the CPU on mainboard powers.
Refer to Fig. 2, described voltage conversion circuit 10 comprises a PWM controller, a first transistor Q1, a transistor seconds Q2, a third transistor Q3, an inductance L and one first electric capacity C1.In one embodiment, described the first transistor Q1, transistor seconds Q2 and third transistor Q3 are N channel field-effect pipe.The grid of described the first transistor Q1 is connected with described PWM controller 11, the drain electrode of described the first transistor Q1 is connected with an input power signal Vin, and the source electrode of described the first transistor Q1 is connected with the drain electrode of described transistor seconds Q2 and the drain electrode of described third transistor Q3; The grid of described transistor seconds Q2 is connected with described PWM controller 11, the source ground of described transistor seconds Q2; Described third transistor Q3 grid is connected with described PWM controller 11, the source ground of described third transistor Q3.One end of described inductance L 1 is connected with the source electrode of described the first transistor Q1, and the other end is connected with the voltage output end Vout of described voltage conversion circuit 10.One end of described first electric capacity C1 is connected with the voltage output end Vout of described voltage conversion circuit 10, other end ground connection.
Described high-pass filtering circuit 20 comprises one second electric capacity C2 and one first resistance R1.One end of described second electric capacity C2 is connected with the voltage output end Vout of described voltage conversion circuit 10, and the other end is connected with a first node A; One end of described first resistance R1 is connected with described first node A, other end ground connection.
Described amplifying circuit 30 comprises one first transport and placing device 31,1 second resistance R2 and the 3rd resistance R3.The positive input of described first transport and placing device 31 is connected with described first node A, and negative input is connected with one end of described second resistance R2, the other end ground connection of described second resistance R2; One end of described 3rd resistance R3 is connected with a Section Point B, and negative input and the described second resistance R2 of the other end and described first transport and placing device 31 are connected.The output terminal of described first transport and placing device 31 is connected with described Section Point B.The enlargement factor of described amplifying circuit 30 is (R2+R3)/R2.
Described peak value checking circuit 40 comprises one second transport and placing device 41, diode D1 and the 3rd electric capacity C3.The positive input of described second transport and placing device 41 is connected with described Section Point B, and negative input is connected with one the 3rd node C.The negative pole of described diode D1 is connected with described 3rd node C, and positive pole is connected with the output terminal of described second transport and placing device 41.One end of described 3rd electric capacity C3 is connected with described 3rd node C, other end ground connection.
Described comparator circuit 50 comprises one the 3rd transport and placing device 51, the 4th transistor Q4, one the 4th resistance R4, one the 5th resistance R5 and the 4th electric capacity C4.The negative input of described 3rd transport and placing device 51 is connected with described 3rd node C, positive input connects a reference voltage Vref, the output terminal of described 3rd transport and placing device 51 is connected with the grid of described 4th transistor Q4, the drain electrode of described 4th transistor Q4 is connected with one end of described 4th resistance R4, and the other end of described 4th resistance R4 is connected with one the 4th node D; The source ground of described 4th transistor Q4; One end of described 5th resistance R5 is connected with described 4th node D, the voltage of another termination one+5V; One end of described 4th electric capacity C4 is connected with described 4th node D, other end ground connection.In one embodiment, described 4th transistor Q4 is N channel field-effect pipe.
During described feed circuit work, described PWM controller 11 controls the ON/OFF state switching described the first transistor Q1, transistor seconds Q2 and third transistor Q3, discharge and recharge action is carried out to inductance L 1 and the first electric capacity C1, thus exports corresponding voltage to described voltage output end Vout, the flip-flop of the output voltage signal of described voltage conversion circuit 10 filters by described high-pass filtering circuit 20, leaves the ripple of alternating component, and the voltage of this ripple is supplied to the positive input of described first transport and placing device 31 by first node A, after the ripple voltage that high-pass filtering circuit 20 exports by described first transport and placing device 31 carries out amplification process, described peak value checking circuit 40 is supplied to by Section Point B, described peak value checking circuit 40 detects the peak value of ripple voltage, and the ripple voltage this with this peak value exports the negative input of described 3rd transport and placing device 51 to by the 3rd node C, the peak value of this ripple voltage and described reference voltage Vref are made comparisons by described 3rd transport and placing device 51, if when the peak value of ripple voltage is less than described reference voltage Vref, the signal that described 3rd transport and placing device 51 exports high level makes described 4th transistor Q4 conducting, now the 4th node D has one first voltage, when described PWM controller 11 receives described first voltage signal, reduce and switch described the first transistor Q1, the frequency of transistor seconds Q2 and third transistor Q3, ripple voltage can increase, if when the peak value of ripple voltage is more than or equal to described reference voltage Vref, the signal of described 3rd transport and placing device 51 output low level makes described 4th transistor Q4 end, now described 4th node D has one second voltage, described second voltage is greater than described first voltage, when described PWM controller 11 receives described second voltage signal, improve the frequency switching described the first transistor Q1, transistor seconds Q2 and third transistor Q3, ripple voltage can reduce.
Described feed circuit when being less than default threshold value at ripple voltage, can reduce the frequency of switching transistor switch, reduce the handoff loss of transistor switch; When ripple voltage is greater than default threshold value, improve the frequency of switching transistor switch, reduce ripple voltage, so, ripple voltage can be controlled in the scope preset, farthest can also reduce the frequency of switching transistor switch, reduce the handoff loss of transistor switch, obtain best balance between.
Claims (10)
1. feed circuit, comprise a voltage conversion circuit, described voltage conversion circuit comprises the transistor switch that a PWM controller and multiple and described controller are connected, described PWM controller controls the state switching described multiple transistor switch, it is characterized in that: described feed circuit also comprise a comparator circuit be connected with described PWM controller, the ripple voltage of the output voltage signal of described voltage conversion circuit and the threshold value preset compare by described comparator circuit, if the peak value of described ripple voltage is less than described default threshold value, described comparator circuit exports one first signal to described PWM controller, described PWM controller reduces the frequency switching described transistor switch, if the peak value of described ripple voltage is not less than described default threshold value, described comparator circuit exports a secondary signal to described PWM controller, and described PWM controller improves the frequency switching described transistor switch.
2. feed circuit as claimed in claim 1, it is characterized in that: described feed circuit also comprise a high-pass filtering circuit be connected with the voltage output end of described voltage conversion circuit, the flip-flop of the output voltage signal of described voltage conversion circuit filters out by described high-pass filtering circuit, obtains described ripple signal.
3. feed circuit as claimed in claim 2, it is characterized in that: described high-pass filtering circuit comprises one first resistance and one second electric capacity, one end of described second electric capacity is connected with the voltage output end of described voltage conversion circuit, and the other end is connected with a first node; One end of described first resistance is connected with described first node, other end ground connection, and described high-pass filtering circuit exports described ripple voltage by described first node.
4. feed circuit as claimed in claim 3, it is characterized in that: described feed circuit also comprise an amplifying circuit, described amplifying circuit is connected with described first node, and the ripple voltage exported by described high-pass filtering circuit carries out amplification process.
5. feed circuit as claimed in claim 4, it is characterized in that: described amplifying circuit includes one first transport and placing device, one second resistance and one the 3rd resistance, the positive input of described first transport and placing device is connected with described first node, negative input is connected with one end of described second resistance, the other end ground connection of described second resistance; One end of described 3rd resistance is connected with a Section Point, and negative input and described second resistance of the other end and described first operational amplifier are connected; The output terminal of described first operational amplifier is connected with described Section Point; Described amplifying circuit exports the ripple voltage signal after amplifying by described Section Point.
6. feed circuit as claimed in claim 5, it is characterized in that: the voltage of described second resistance is R2, the voltage of described 3rd resistance is R3, and described amplifying circuit is (R2+R3)/R2 to the multiple that described ripple voltage amplifies.
7. feed circuit as claimed in claim 6, it is characterized in that: described feed circuit also comprise a peak value checking circuit, described peak value checking circuit exports the peak value of the ripple voltage amplified through described amplifying circuit to described comparator circuit.
8. feed circuit as claimed in claim 7, is characterized in that: described peak value checking circuit comprises one second transport and placing device, a diode and one the 3rd electric capacity; The positive input of described second transport and placing device is connected with described Section Point, and negative input is connected with one the 3rd node; The negative pole of described diode is connected with described 3rd node, and positive pole is connected with the output terminal of described second transport and placing device; One end of described 3rd electric capacity is connected with described 3rd node, other end ground connection; Described peak value checking circuit exports the peak value of the ripple voltage after amplifying by described 3rd node.
9. feed circuit as claimed in claim 8, it is characterized in that: described comparator circuit comprises one the 3rd transport and placing device, the negative input of described 3rd transport and placing device is connected with described 3rd node, positive input connects a reference voltage, and the output terminal of described 3rd transport and placing device is connected with described PWM controller.
10. feed circuit as claimed in claim 9, it is characterized in that: described comparator circuit also comprises a transistor, one the 4th resistance and one the 5th resistance, the output terminal of described 3rd transport and placing device is connected with the grid of described transistor, the drain electrode of described transistor is connected with described 4th resistance one end, and the other end of described 4th resistance R is connected with one the 4th node; The source ground of described transistor; One end of described 5th resistance is connected with described 4th node, another termination one power supply signal; Described comparator circuit exports compare result signal to described PWM controller by described 4th node.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310225281.6A CN104238702A (en) | 2013-06-07 | 2013-06-07 | Power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310225281.6A CN104238702A (en) | 2013-06-07 | 2013-06-07 | Power supply circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104238702A true CN104238702A (en) | 2014-12-24 |
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ID=52226957
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310225281.6A Pending CN104238702A (en) | 2013-06-07 | 2013-06-07 | Power supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104238702A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105338693A (en) * | 2015-09-22 | 2016-02-17 | 深圳市稳先微电子有限公司 | Driving chip and single-stage high-power-factor LED driving device |
| CN106712509A (en) * | 2016-12-21 | 2017-05-24 | 深圳市华星光电技术有限公司 | Power circuit and liquid crystal display |
-
2013
- 2013-06-07 CN CN201310225281.6A patent/CN104238702A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105338693A (en) * | 2015-09-22 | 2016-02-17 | 深圳市稳先微电子有限公司 | Driving chip and single-stage high-power-factor LED driving device |
| CN105338693B (en) * | 2015-09-22 | 2017-11-10 | 深圳市稳先微电子有限公司 | A kind of driving chip and single-stage high-power rate factor LED drive device |
| CN106712509A (en) * | 2016-12-21 | 2017-05-24 | 深圳市华星光电技术有限公司 | Power circuit and liquid crystal display |
| CN106712509B (en) * | 2016-12-21 | 2019-07-23 | 深圳市华星光电技术有限公司 | A kind of power circuit and liquid crystal display |
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| Date | Code | Title | Description |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20141224 |