CN118100627A - PFC output voltage regulating circuit of switching power supply - Google Patents
PFC output voltage regulating circuit of switching power supply Download PDFInfo
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- CN118100627A CN118100627A CN202410497126.8A CN202410497126A CN118100627A CN 118100627 A CN118100627 A CN 118100627A CN 202410497126 A CN202410497126 A CN 202410497126A CN 118100627 A CN118100627 A CN 118100627A
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- 230000000087 stabilizing effect Effects 0.000 claims abstract description 17
- 230000003287 optical effect Effects 0.000 claims abstract description 12
- 239000003990 capacitor Substances 0.000 claims description 15
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 230000003139 buffering effect Effects 0.000 description 1
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Abstract
The invention belongs to the technical field of switching power supplies, and discloses a PFC output voltage regulating circuit of a switching power supply, which comprises a power supply VCCA, a controllable precise voltage stabilizing source U1, an MCU, an optical coupler OT1 and a voltage follower IC1, wherein the power supply VCCA is connected with one end of a resistor R12, the other end of the resistor R12 is connected with a pin 3 of the controllable precise voltage stabilizing source U1, one end of a resistor R10 and one end of a resistor R8, a pin 1 of the controllable precise voltage stabilizing source U1 is connected with the other end of the resistor R10 and one end of a resistor R11, and the other end of the resistor R11 and a pin 2 of the controllable precise voltage stabilizing source U1 are connected with a port GND. The invention has the beneficial effects that: the high-efficiency operation of the power supply is realized under the condition of wide output voltage, and the performance of the switching power supply is greatly improved.
Description
Technical Field
The invention relates to the technical field of switching power supplies, in particular to a PFC output voltage regulating circuit of a switching power supply.
Background
In a switching power supply, the PFC bus voltage is typically set to a constant value, but in some applications, PFC setting to a constant value does not allow the power supply to operate efficiently. As market demands are higher, a wide input voltage and output voltage range is a common application, and in order to improve the PF value and the efficiency of the power supply, it is generally required to make the power supply work in an optimal state by changing the PFC bus voltage, so that the power supply has lower cost, smaller volume and higher efficiency. Based on the above, the voltage regulation of the PFC bus is particularly important, and under the condition of wide output voltage requirement, the different values of the voltage of the PFC bus are regulated to meet enough gain, so that the power supply can operate efficiently under all output voltages.
Therefore, it is necessary to provide a PFC output voltage regulator circuit for a switching power supply that achieves efficient operation of the power supply under wide output voltage conditions.
Disclosure of Invention
The invention discloses a PFC output voltage regulating circuit of a switching power supply, which can effectively solve the technical problems related to the background technology.
In order to achieve the above purpose, the technical scheme of the invention is as follows:
A PFC output voltage regulating circuit of a switching power supply comprises a power supply VCCA, a controllable precise voltage stabilizing source U1, an MCU, an optical coupler OT1 and a voltage follower IC1;
The power supply VCCA is connected with one end of a resistor R12, the other end of the resistor R12 is connected with a pin 3 of the controllable precise voltage stabilizing source U1, one end of a resistor R10 and one end of a resistor R8, the pin 1 of the controllable precise voltage stabilizing source U1 is connected with the other end of the resistor R10 and one end of a resistor R11, and the other end of the resistor R11 and the pin 2 of the controllable precise voltage stabilizing source U1 are connected with a port GND;
the MCU is connected with one end of a resistor R9, the other end of the resistor R9 is connected with the anode of the diode of the optical coupler OT1, and the cathode of the diode of the optical coupler OT1 is connected with a port GND;
The other end of the resistor R8 is connected with the collector electrode of the triode of the optical coupler OT1, one end of the resistor R7 and one end of the resistor R6, the other end of the resistor R6 is connected with one end of the resistor R5 and one end of the capacitor C4, the other end of the resistor R5 is connected with one end of the capacitor C3, one end of the capacitor C2 and the pin 3 of the voltage follower IC1, the pin 1 of the voltage follower IC1 is connected with one end of the resistor R4, the other end of the resistor R4 is connected with one end of the resistor R2, one end of the resistor R3 and one end of the capacitor C1, the other end of the resistor R2 is connected with a bus output voltage port VDC through the resistor R1, and the emitter electrode of the triode of the optical coupler OT1, the other end of the resistor R7, the other end of the capacitor C4, the other end of the capacitor C3, the other end of the resistor R3 and the other end of the capacitor C1 are connected with a port GND.
Specifically, the voltage regulating circuit may be divided into a reference voltage generating circuit, a PWM signal generating circuit, a voltage follower circuit, and a PFC control chip feedback boost circuit. The anode of the controllable precise voltage-stabilizing source is connected with a current-limiting resistor, the other end of the current-limiting resistor is connected with a voltage-stabilizing power supply circuit for supplying power to the controllable precise voltage-stabilizing source, and the reference electrode of the controllable precise voltage-stabilizing source is connected with two voltage-dividing resistors for providing a reference voltage. The light emitting diode of the optocoupler is connected with the MCU chip, the other triode is connected with the feedback pin of the PFC chip, and the optocoupler is controlled by PWM signals, so that the partial pressure at two ends of the optocoupler is changed. The reference voltage is connected to the voltage follower through the current limiting resistor and the filter capacitor, so that a voltage buffering effect is realized, and the output voltage changes along with the input voltage. The output end of the voltage follower circuit is connected with a feedback pin (a resistor R4) of the PFC control chip, one side of the feedback pin is connected with a voltage dividing resistor to the ground, the other side is connected with a resistor to an output bus, and the voltage of the bus is regulated by regulating the voltage of the feedback pin. According to the invention, the voltage at the feedback pin of the PFC chip is regulated, so that the switching power supply can achieve enough gain by regulating the bus output voltage under the condition of larger output voltage range, and the performance of the switching power supply is greatly improved.
As a preferred improvement of the present invention: the model U1 of the controllable precise voltage stabilizing source is AZ431.
As a preferred improvement of the present invention: the MCU is an STM32 series singlechip.
As a preferred improvement of the present invention: the other end of the resistor R4 is connected with a feedback pin of the PFC control chip IC 2.
As a preferred improvement of the present invention: the model of the PFC control chip IC2 is NCP1654.
The beneficial effects of the invention are as follows: the circuit has simple structure and stable operation, realizes the regulation of the voltage of the output bus through the structures of the controllable precise voltage stabilizing source U1, the MCU, the optocoupler OT1, the voltage follower IC1 and the like, can realize the high-efficiency operation of the power supply under the condition of wide output voltage, achieves enough gain and greatly improves the performance of the switching power supply.
Drawings
For a clearer description of the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:
Fig. 1 is a schematic diagram of a PFC output voltage regulator circuit of a switching power supply according to the present invention.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.
Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In addition, the technical solutions of the embodiments of the present invention may be combined with each other, but it is necessary to be based on the fact that those skilled in the art can implement the technical solutions, and when the technical solutions are contradictory or cannot be implemented, the combination of the technical solutions should be considered as not existing, and not falling within the scope of protection claimed by the present invention.
Referring to fig. 1, the present invention provides a PFC output voltage regulator circuit for a switching power supply, which includes a power supply VCCA (input power supply), a controllable precision voltage stabilizing source U1 (TL 431), an MCU, an optical coupler OT1, and a voltage follower IC1 (operational amplifier), and may be divided into a reference voltage generating circuit, a PWM signal generating circuit, a voltage follower circuit, and a PFC control chip feedback boost circuit. In this embodiment, the controllable precise voltage stabilizing source U1 is AZ431, the MCU is STM32 series singlechip, and the OT1 is: LTV1009, IC1 model: LM2904.
The reference voltage generating circuit, the one end of resistance R12 is connected to power VCCA, pin 3 (positive pole) of controllable accurate steady voltage source U1, one end of resistance R10 and one end of resistance R8 are connected to the other end of controllable accurate steady voltage source U1 (reference pole) connect the other end of resistance R10 and one end of resistance R11, the other end of resistance R11 and pin 2 of controllable accurate steady voltage source U1 connect port GND (ground), and the reference pole of controllable accurate steady voltage source provides the reference voltage.
The PWM signal generating circuit, MCU connects the one end of resistance R9, the other end of resistance R9 is connected the positive pole of opto-coupler OT 1's diode, the negative pole of opto-coupler OT 1's diode is connected port GND, the collector of opto-coupler OT 1's phototriode connects the one end of resistance R6, opto-coupler OT 1's phototriode's projecting pole ground, adjusts opto-coupler phototriode's conduction degree through MCU's control to change the split pressure resistance at both ends, change the voltage at resistance R7 both ends.
The voltage follower circuit, the other end of resistance R8 is connected the triode of opto-coupler OT 1's collecting electrode, the one end of resistance R7 and the one end of resistance R6, the one end of resistance R5 and the one end of electric capacity C4 are connected to the other end of resistance R6, the one end of electric capacity C3, the one end of electric capacity C2 and the pin 3 (input) of voltage follower IC1 are connected to the other end of resistance R5, the one end of resistance R4 is connected to the pin 1 (output) of voltage follower IC1, the pin 2 of voltage follower IC1 with the other end of electric capacity C2, the triode of opto-coupler OT 1's projecting pole, the other end of resistance R7, the other end of electric capacity C4 and the other end ground connection of electric capacity C3.
The PFC control chip feeds back the boost circuit, the other end of resistance R4 connects one end of resistance R2, one end of resistance R3 and one end of electric capacity C1, the other end of resistance R2 passes through resistance R1 and connects PFC busbar output voltage port VDC, the other end of resistance R3 with the other end of electric capacity C1 connects port GND, through changing the reference voltage and change the voltage of the other end of resistance R4, and then adjusts busbar output voltage (port VDC+). In this embodiment, the other end of the resistor R4 is connected to a feedback pin of the PFC control chip IC2, the PFC control chip IC2 is a basic device of the PFC circuit, and the resistor R4 is connected to the PFC control chip IC2, so that the voltage at the resistor R4 can be sampled, and further, the value of the bus output voltage can be determined, and the regulation of the output bus voltage can be realized by regulating the voltage at the feedback pin of the PFC control chip, so that efficient operation of the power supply can be realized under the condition of wide output voltage. Preferably, the PFC control chip IC2 is of the NCP1654 type.
Although embodiments of the present invention have been disclosed above, it is not limited to the details and embodiments shown and described, it is well suited to various fields of use for which the invention would be readily apparent to those skilled in the art, and accordingly, the invention is not limited to the specific details and illustrations shown and described herein, without departing from the general concepts defined in the claims and their equivalents.
Claims (5)
1. The PFC output voltage regulating circuit of the switching power supply is characterized in that: the device comprises a power supply VCCA, a controllable precise voltage stabilizing source U1, an MCU, an optical coupler OT1 and a voltage follower IC1;
The power supply VCCA is connected with one end of a resistor R12, the other end of the resistor R12 is connected with a pin 3 of the controllable precise voltage stabilizing source U1, one end of a resistor R10 and one end of a resistor R8, the pin 1 of the controllable precise voltage stabilizing source U1 is connected with the other end of the resistor R10 and one end of a resistor R11, and the other end of the resistor R11 and the pin 2 of the controllable precise voltage stabilizing source U1 are connected with a port GND;
the MCU is connected with one end of a resistor R9, the other end of the resistor R9 is connected with the anode of the diode of the optical coupler OT1, and the cathode of the diode of the optical coupler OT1 is connected with a port GND;
The other end of the resistor R8 is connected with the collector electrode of the triode of the optical coupler OT1, one end of the resistor R7 and one end of the resistor R6, the other end of the resistor R6 is connected with one end of the resistor R5 and one end of the capacitor C4, the other end of the resistor R5 is connected with one end of the capacitor C3, one end of the capacitor C2 and the pin 3 of the voltage follower IC1, the pin 1 of the voltage follower IC1 is connected with one end of the resistor R4, the other end of the resistor R4 is connected with one end of the resistor R2, one end of the resistor R3 and one end of the capacitor C1, the other end of the resistor R2 is connected with a bus output voltage port VDC through the resistor R1, and the emitter electrode of the triode of the optical coupler OT1, the other end of the resistor R7, the other end of the capacitor C4, the other end of the capacitor C3, the other end of the resistor R3 and the other end of the capacitor C1 are connected with a port GND.
2. The switching power supply PFC output voltage regulator circuit of claim 1, wherein: the model U1 of the controllable precise voltage stabilizing source is AZ431.
3. The switching power supply PFC output voltage regulator circuit of claim 1, wherein: the MCU is an STM32 series singlechip.
4. The switching power supply PFC output voltage regulator circuit of claim 1, wherein: the other end of the resistor R4 is connected with a feedback pin of the PFC control chip IC 2.
5. A switching power supply PFC output voltage regulator circuit according to claim 4, wherein: the model of the PFC control chip IC2 is NCP1654.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410497126.8A CN118100627A (en) | 2024-04-24 | 2024-04-24 | PFC output voltage regulating circuit of switching power supply |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410497126.8A CN118100627A (en) | 2024-04-24 | 2024-04-24 | PFC output voltage regulating circuit of switching power supply |
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| CN118100627A true CN118100627A (en) | 2024-05-28 |
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| CN202410497126.8A Pending CN118100627A (en) | 2024-04-24 | 2024-04-24 | PFC output voltage regulating circuit of switching power supply |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103427619A (en) * | 2012-05-24 | 2013-12-04 | 珠海格力电器股份有限公司 | PFC control circuit with capability of flexible boosting and control method thereof |
| CN205753967U (en) * | 2016-05-09 | 2016-11-30 | 深圳市金威源科技股份有限公司 | A kind of simulation PFC Linear voltage-adjusting circuit |
| CN107968575A (en) * | 2017-12-25 | 2018-04-27 | 广州金升阳科技有限公司 | A kind of feedback control circuit |
| CN110266182A (en) * | 2019-05-20 | 2019-09-20 | 杭州电子科技大学 | A kind of adaptive following controller of PFC output voltage |
| JP2020078155A (en) * | 2018-11-07 | 2020-05-21 | ローム株式会社 | Power controller, and llc resonant converter |
| CN216530680U (en) * | 2022-04-08 | 2022-05-13 | 广东高斯宝电气技术有限公司 | Battery charging circuit of electric vehicle |
| CN115313863A (en) * | 2022-08-08 | 2022-11-08 | 深圳创客恒源科技有限公司 | Circuit and method for adjusting PFC (power factor correction) and LLC (logical link control) topology output voltage based on output requirement |
-
2024
- 2024-04-24 CN CN202410497126.8A patent/CN118100627A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103427619A (en) * | 2012-05-24 | 2013-12-04 | 珠海格力电器股份有限公司 | PFC control circuit with capability of flexible boosting and control method thereof |
| CN205753967U (en) * | 2016-05-09 | 2016-11-30 | 深圳市金威源科技股份有限公司 | A kind of simulation PFC Linear voltage-adjusting circuit |
| CN107968575A (en) * | 2017-12-25 | 2018-04-27 | 广州金升阳科技有限公司 | A kind of feedback control circuit |
| JP2020078155A (en) * | 2018-11-07 | 2020-05-21 | ローム株式会社 | Power controller, and llc resonant converter |
| CN110266182A (en) * | 2019-05-20 | 2019-09-20 | 杭州电子科技大学 | A kind of adaptive following controller of PFC output voltage |
| CN216530680U (en) * | 2022-04-08 | 2022-05-13 | 广东高斯宝电气技术有限公司 | Battery charging circuit of electric vehicle |
| CN115313863A (en) * | 2022-08-08 | 2022-11-08 | 深圳创客恒源科技有限公司 | Circuit and method for adjusting PFC (power factor correction) and LLC (logical link control) topology output voltage based on output requirement |
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