CN209419502U - Power supply circuit, control circuit and Switching Power Supply - Google Patents
Power supply circuit, control circuit and Switching Power Supply Download PDFInfo
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- CN209419502U CN209419502U CN201822251405.9U CN201822251405U CN209419502U CN 209419502 U CN209419502 U CN 209419502U CN 201822251405 U CN201822251405 U CN 201822251405U CN 209419502 U CN209419502 U CN 209419502U
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Abstract
The utility model discloses a kind of power supply circuit, control circuit and Switching Power Supplies, including first switch and voltage detecting circuit, the first end of the first switch is power supply incoming end, receives supply voltage, and the second end of the first switch is treated power supply circuit as power supply output end and is powered；The voltage detecting circuit samples the voltage of the first switch first end or second end, obtains voltage sampling signal, and the voltage sampling signal is compared with first threshold, and the voltage detecting circuit exports first control signal；When the voltage sampling signal is lower than first threshold, the first control signal characterizes low-power consumption triggering command.The utility model can be realized powered stable, be conducive to the normal work of circuit to be powered, and peripheral components are few.
Description
Technical field
The utility model relates to a kind of power electronics field, in particular to a kind of power supply circuit, control circuit and
Switching Power Supply.
Background technique
In the prior art, inductive current and output voltage are usually sampled to load supplying using Switching Power Supply, and according to phase
The sampled signal answered is fed back, to realize the adjusting to output electric current or output voltage.
In isolation type switching power supply, when input terminal is electrolytic capacitor, it is typically employed in low power factor scene, it is female
Line voltage fluctuation is smaller, and input voltage VIN is not less than the normal working voltage range of control circuit.But work as input capacitance
When smaller, especially under High Power Factor scene, input voltage VIN fluctuation is larger, as shown in Figure 1, input voltage VIN it is close or
Equal to zero, the normal working voltage of control circuit need to be higher than V1, easily be lower than normal range of operation lower than chip supply voltage, because
This may cause control circuit or chip power-down, can not work normally when input voltage VIN is lower than V1.
Utility model content
In view of this, the purpose of the utility model is to provide a kind of power supply circuit of powered stable, control circuit and opening
Powered-down source, with solve control circuit of the existing technology or chip may power down the technical issues of.
To achieve the above object, the utility model provides a kind of power supply circuit, including first switch and voltage detecting electricity
Road, the first end of the first switch are power supply incoming end, receive supply voltage, the second end of the first switch is as power supply
Output end is treated power supply circuit and is powered；The voltage detecting circuit samples the electricity of the first switch first end or second end
Pressure, obtains voltage sampling signal, the voltage sampling signal is compared with first threshold, the voltage detecting circuit output
First control signal；When the voltage sampling signal is lower than first threshold, the first control signal characterizes triggering command.
Optionally, the first switch is transistor, and the transistor is connected in the case where controlled or uncontrolled with right
Circuit power supply to be powered, the conducting are fully on or incomplete conducting.
Optionally, the transistor is junction field effect transistor, when supply voltage is lower than the junction field effect transistor
When the pinch-off voltage of pipe, the junction field effect transistor conducting.
Optionally, the voltage detecting circuit includes first comparator, described in the first end reception of the first comparator
The second end of voltage sampling signal, the first comparator receives the first threshold, and the output end of the first comparator is defeated
The first control signal out.
The utility model provides a kind of control circuit, including any one of the above power supply circuit and circuit to be powered, institute
Power supply circuit is stated to power to the circuit to be powered.
The utility model additionally provide a kind of Switching Power Supply, including any one of the above power supply circuit, circuit to be powered with
And switching circuit, the power supply circuit receive the busbar voltage of the Switching Power Supply, power to the circuit to be powered, it is described to
Power supply circuit exports second control signal, for controlling the switch state of the switching circuit.
Optionally, the power supply circuit includes voltage detecting circuit, and the voltage detecting circuit samples the first switch
The voltage of first end or second end obtains voltage sampling signal, and the voltage detecting circuit exports first control signal, in voltage
When sampled signal is lower than first threshold, the first control signal characterizes triggering command, and the circuit to be powered receives the touching
Send instructions, then control the switching circuit frequency reducing work or stops working.
Optionally, the circuit to be powered includes logic circuit and reference generating circuit, and the reference generating circuit receives
The first voltage signal of current reference signal and characterization inductive current peak, the first voltage signal obtain characterization through conversion and put down
The average value signal of equal inductive current obtains reference signal, the logic according to the current reference signal and average value signal
Circuit receives the reference signal, and in logic circuits, the reference signal is compared with ramp signal, to determine main switch
The shutdown moment of pipe, and be characterized in second control signal, the output end of logic circuit is connect with driver.
Optionally, the circuit to be powered further includes zero cross detection circuit, the input terminal of the zero cross detection circuit and institute
The control terminal connection of main switch is stated, the output end of the zero cross detection circuit is connect with logic circuit.
Compared with prior art, the technical solution of the utility model have the advantage that the utility model for detect confession
The voltage of circuit, when the voltage is lower than the voltage that control circuit works normally, the first control signal characterizes low-power consumption
Triggering command receives the low-power consumption triggering command by circuit to be powered, and control switch circuit enter low-power consumption mode (including
But it is not limited to frequency reducing work, stops working), to prevent circuit power down to be powered.The utility model can be realized powered stable, have
Conducive to the normal work of circuit to be powered, peripheral components are few.
Detailed description of the invention
Fig. 1 is the input voltage waveform schematic diagram of the prior art；
Fig. 2 is the circuit theory schematic diagram of the utility model Switching Power Supply；
Fig. 3 is the electrical block diagram of the utility model power supply circuit；
Fig. 4 is the electrical block diagram of overvoltage protective module.
Specific embodiment
It is described in detail below in conjunction with preferred embodiment of the attached drawing to the utility model, but the utility model is not merely
It is limited to these embodiments.The utility model covers any substitution made in the spirit and scope of the utility model, modification, equivalent
Method and scheme.
In order to make the public have thorough understanding to the utility model, in following the preferred embodiment in the utility model specifically
Concrete details is illustrated, and that this can also be understood completely is practical new for description without these details for a person skilled in the art
Type.
The utility model is more specifically described by way of example referring to attached drawing in the following passage.It should be noted that attached drawing
It is all made of more simplified form and uses non-accurate ratio, only to facilitate, lucidly aid in illustrating the utility model
The purpose of embodiment.
As shown in Fig. 2, the circuit theory of the utility model Switching Power Supply is illustrated, based on Flyback topological structure, and
On the basis of Switching Power Supply, rectifier bridge is set in its front end, using LED as load, may be used as LED drive circuit.
Wherein, the power supply circuit of the utility model and circuit composition control circuit to be powered, the control circuit is using collection
At the form of circuit, but it is not limited to the form using integrated circuit.The VIN pin of the chip of control circuit is integrated with as power supply
The power supply incoming end of circuit, the GATE of chip are control pin, for main switch M transmission of control signals, CS pin to be to adopt
Sample pin, pressure drop on sampling resistor R1 or the electric current for flowing through resistance R1, OVP pin is overvoltage protection pin, can be by outer
The trigger voltage of overvoltage protection is arranged in the resistance R2 set, and GND is conventional grounding pin.
As shown in figure 3, illustrating the circuit structure of the utility model power supply circuit.The power supply circuit of the utility model includes
The first end of first switch J and voltage detecting circuit U01, the first switch J are power supply incoming end, receive supply voltage VIN,
The second end of the first switch J is treated power supply circuit as power supply output end and is powered；The voltage detecting circuit sampling
The voltage of the first switch J first end or second end, obtains voltage sampling signal Vs, by the voltage sampling signal Vs and
One threshold value V1 is compared, and the voltage detecting circuit exports first control signal Vctrl1；In the voltage sampling signal Vs
When lower than first threshold V1, the first control signal Vctrl1 characterizes low-power consumption triggering command.The voltage detecting circuit packet
Including first comparator, the first end of the first comparator receives the voltage sampling signal Vs, and the of the first comparator
Two ends receive the first threshold V1, and the output end of the first comparator exports the first control signal Vctrl1.
The first switch J is transistor, and the transistor is connected in the case where controlled or uncontrolled to be powered
Circuit power supply, the conducting are fully on or incomplete conducting.MOSFET, control can be used according to controlled transistor
Its is fully on or partially ON；If uncontrolled transistor, then JFET can be used.According to JFET, better effect,
By taking high pressure JFET as an example, when supply voltage VIN is lower than the pinch-off voltage of high pressure JFET, JFET conducting；Otherwise cut-off, in this way may be used
With the situation for preventing supply voltage VIN excessively high.Control circuit (IC) only needs minimum filter capacitor or, single as the filtering
Member, or capacitor can not be needed, save external power supply capacitor.
When the first control signal Vctrl1 characterization triggering command, the triggering command has mode switch function, with
Into for low-power consumption mode, logic circuit receives the triggering command, wherein a part of logic circuit as circuit to be powered,
The power supply of entire control chip relies primarily on the power supply circuit of the utility model.Second control signal is exported by logic circuit
Vctrl2, the second control signal Vctrl2 are used to control the switch state of the switching circuit, in first control signal
When Vctrl1 characterizes low-power consumption triggering command, the second control signal Vctrl2 control switch circuit enters low-power consumption mode,
The low-power consumption mode includes frequency reducing work or stops working.
The present invention is applied in Switching Power Supply, and the Switching Power Supply includes power supply circuit, circuit to be powered and switch electricity
Road, wherein switching tube M is the switching tube on secondary side, and the power supply circuit receives the busbar voltage of the Switching Power Supply, i.e. power supply electricity
VIN is pressed, is powered to the circuit to be powered, the circuit output second control signal Vctrl2 to be powered is described for controlling
The switch state of switching circuit.In order to provide the efficiency of Switching Power Supply, can be used using the Switching Power Supply of the utility model critical
Conduction mode (BCM) work.The shutdown moment of the primary side of the switching circuit is determined by the reference generating circuit, it is described wait supply
Circuit includes logic circuit and reference generating circuit, and the reference generating circuit receives current reference signal and characterization inductance electricity
The first voltage signal of stream peak value, the first voltage signal obtain the average value signal of characterization average inductor current through converting,
According to the current reference signal and average value signal, reference signal is obtained, the logic circuit receives the reference signal,
In logic circuit, the reference signal is compared with ramp signal, to determine the shutdown moment of main switch, and is characterized in
On two control signals, the output end of logic circuit is connect with driver Driver, the control terminal of the driver and main switch M
Connection.Due to using critical conduction mode, therefore, it is necessary to detect inductive current zero crossing, the prior art flows through electricity by sampling
The electric current of sense, that is, when detecting that secondary inductance is reduced to zero, control switch pipe M is open-minded.The zero passage detection electricity of the utility model
The zero crossing of inductive current is detected on road by the voltage of detection switch pipe M control terminal, and principle is, inductive current zero passage
When, resonance can be generated, when resonance occurs, negative pressure can be generated in the control terminal of primary side switch pipe, therefore, pass through zero passage detection electricity
The voltage of the switching tube M control terminal is detected to realize the detection of zero crossing in road.
As shown in figure 4, illustrating the circuit structure of overvoltage protective module.The utility model is also provided with overvoltage protection function
Energy.The hot end of the input terminal connection input voltage VIN of the overvoltage protective module OVP, the overvoltage protective module sampling
Input voltage VIN, the signal Vs1 that sampling is obtained (sampled signal can be same signal with the voltage sampling signal Vs,
Can also sample respectively as different sampled signals) proportion adjustment is carried out, and it is crossed into pressure reference signal with corresponding
VOVP_REFIt is compared, is judged whether that over-voltage phenomenon occurs according to comparison result, complete to compare in the second comparator COMP2,
The output end of the second comparator COMP2 is connect with logic circuit, to trigger overvoltage protection in over-voltage.The ratio tune
Section uses the proportionality coefficient with main power tube duty ratio direct proportionality, so that opening described in the characterization after proportion adjustment
The output voltage in powered-down source.The pressure reference signal of crossing is generated by reference signal generation circuit, the reference signal generation circuit
Including the overvoltage protection resistance R3 being set to outside piece.
Although embodiment is separately illustrated and is illustrated above, it is related to the common technology in part, in ordinary skill
Personnel apparently, can be replaced and integrate between the embodiments, be related to one of embodiment and the content recorded is not known, then
It can refer to another embodiment on the books.
Embodiments described above does not constitute the restriction to the technical solution protection scope.It is any in above-mentioned implementation
Made modifications, equivalent substitutions and improvements etc., should be included in the protection model of the technical solution within the spirit and principle of mode
Within enclosing.
Claims (9)
1. a kind of power supply circuit, including first switch and voltage detecting circuit, the first end of the first switch is for being electrically accessed
End, receives supply voltage, and the second end of the first switch is treated power supply circuit as power supply output end and is powered；The electricity
Pressure detection circuit samples the voltage of the first switch first end or second end, obtains voltage sampling signal, the voltage is adopted
Sample signal is compared with first threshold, and the voltage detecting circuit exports first control signal；In the voltage sampling signal
When lower than first threshold, the first control signal characterizes triggering command.
2. power supply circuit according to claim 1, it is characterised in that: the first switch is transistor, the transistor
It is connected in the case where controlled or uncontrolled to treat power supply circuit power supply, the conducting is fully on or incomplete conducting.
3. power supply circuit according to claim 2, it is characterised in that: the transistor is junction field effect transistor, when
When supply voltage is lower than the pinch-off voltage of the junction field effect transistor, the junction field effect transistor conducting.
4. power supply circuit according to claim 1,2 or 3, it is characterised in that: the voltage detecting circuit includes the first ratio
Compared with device, the first end of the first comparator receives the voltage sampling signal, and the second end of the first comparator receives institute
First threshold is stated, the output end of the first comparator exports the first control signal.
5. a kind of control circuit, it is characterised in that: including any one power supply circuit of claim 1-4 and circuit to be powered, institute
Power supply circuit is stated to power to the circuit to be powered.
6. a kind of Switching Power Supply, it is characterised in that: including claim 1-4 any one power supply circuit, circuit to be powered and
Switching circuit, the power supply circuit receive the busbar voltage of the Switching Power Supply, power to the circuit to be powered, described wait supply
Electric circuit output second control signal, for controlling the switch state of the switching circuit.
7. Switching Power Supply according to claim 6, it is characterised in that: the power supply circuit includes voltage detecting circuit, institute
The voltage that voltage detecting circuit samples the first switch first end or second end is stated, voltage sampling signal, the voltage are obtained
Detection circuit exports first control signal, when voltage sampling signal is lower than first threshold, the first control signal characterization touching
Send instructions, the circuit to be powered receives the triggering command, then controls the switching circuit frequency reducing work or stop working.
8. Switching Power Supply according to claim 7, it is characterised in that: the circuit to be powered includes logic circuit and benchmark
Generation circuit, the reference generating circuit receive current reference signal and characterize the first voltage signal of inductive current peak, institute
It states first voltage signal and obtains the average value signal of characterization average inductor current through converting, according to the current reference signal peace
Mean value signal, obtains reference signal, and the logic circuit receives the reference signal, in logic circuits, the reference signal
It is compared with ramp signal, to determine the shutdown moment of main switch, and is characterized in second control signal, logic circuit
Output end is connect with driver.
9. Switching Power Supply according to claim 8, it is characterised in that: the circuit to be powered further includes zero passage detection electricity
Road, the input terminal of the zero cross detection circuit are connect with the control terminal of the main switch, the output of the zero cross detection circuit
End is connect with logic circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822251405.9U CN209419502U (en) | 2018-12-29 | 2018-12-29 | Power supply circuit, control circuit and Switching Power Supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822251405.9U CN209419502U (en) | 2018-12-29 | 2018-12-29 | Power supply circuit, control circuit and Switching Power Supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209419502U true CN209419502U (en) | 2019-09-20 |
Family
ID=67941694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201822251405.9U Active CN209419502U (en) | 2018-12-29 | 2018-12-29 | Power supply circuit, control circuit and Switching Power Supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209419502U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109586598A (en) * | 2018-12-29 | 2019-04-05 | 杰华特微电子（杭州）有限公司 | A kind of power supply circuit, control circuit and Switching Power Supply |
| CN112650377A (en) * | 2020-12-22 | 2021-04-13 | 海光信息技术股份有限公司 | I2C bus pull-up power supply method, circuit and chip |
| CN113675817A (en) * | 2021-07-02 | 2021-11-19 | 富满微电子集团股份有限公司 | Overvoltage protection circuit, overvoltage protection method and chip |
-
2018
- 2018-12-29 CN CN201822251405.9U patent/CN209419502U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109586598A (en) * | 2018-12-29 | 2019-04-05 | 杰华特微电子（杭州）有限公司 | A kind of power supply circuit, control circuit and Switching Power Supply |
| CN112650377A (en) * | 2020-12-22 | 2021-04-13 | 海光信息技术股份有限公司 | I2C bus pull-up power supply method, circuit and chip |
| CN113675817A (en) * | 2021-07-02 | 2021-11-19 | 富满微电子集团股份有限公司 | Overvoltage protection circuit, overvoltage protection method and chip |
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| GR01 | Patent grant | ||
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| CP03 | Change of name, title or address |
Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 424, building 1, 1500 Wenyi West Road, Cangqian street, Yuhang District, Hangzhou City, Zhejiang Province Patentee before: JOULWATT TECHNOLOGY (HANGZHOU) Co.,Ltd. |