CN220492857U - Compensation circuit and switching power supply - Google Patents
Compensation circuit and switching power supply Download PDFInfo
- Publication number
- CN220492857U CN220492857U CN202321941943.5U CN202321941943U CN220492857U CN 220492857 U CN220492857 U CN 220492857U CN 202321941943 U CN202321941943 U CN 202321941943U CN 220492857 U CN220492857 U CN 220492857U
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- 238000001514 detection method Methods 0.000 claims abstract description 22
- 238000002955 isolation Methods 0.000 claims abstract description 14
- 238000012545 processing Methods 0.000 claims abstract description 4
- 230000009977 dual effect Effects 0.000 claims description 3
- 238000013461 design Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 206010063385 Intellectualisation Diseases 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
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- 238000012986 modification Methods 0.000 description 1
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- 238000003199 nucleic acid amplification method Methods 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The utility model relates to a compensation circuit and a switching power supply, wherein the compensation circuit comprises a detection circuit, a subtraction operation circuit, an isolation operational amplifier circuit and a main control IC which are connected in sequence; the detection circuit is used for detecting an output voltage signal of the switching power supply and outputting a Va level signal after voltage division processing; the subtracting circuit is used for subtracting the Va level signal from the reference signal VREF to generate a Vb level signal which is inversely related to the Va level signal; the isolation operational amplifier circuit is used for amplifying a Vb level signal to generate a Vc level signal and outputting the Vc level signal to a COMP pin of the main control IC so that the main control IC compensates internally according to the Vc level signal; the circuit can realize the compensation of performance errors caused by gain variation, such as the consistency of overcurrent points, ripple noise, working modes and the like of the switching power supply under different gains.
Description
Technical Field
The utility model relates to the technical field of switching power supplies, in particular to a compensation circuit and a switching power supply.
Background
Along with the development of the power electronics industry, the intellectualization and the high efficiency become the necessary trend of the development of the switching power supply. Meanwhile, the application of the power supply is wider and wider, and in certain specific occasions, the output voltage range of the switching power supply is required to be wider, so that the switching power supply is required to realize wider gain. However, most conventional power ICs only compensate for performance errors caused by gain changes when input voltages change, and lack of compensation for performance errors caused by gain changes when output voltages change, and meanwhile, certain high-efficiency topologies, such as LLC and forward, have a narrow gain range, so that if wide gains are realized by using these topologies, it is more necessary to compensate for performance errors caused by gain changes when output voltages change.
Disclosure of Invention
The utility model aims to overcome at least one defect of the prior art, and provides a compensation circuit and a switching power supply, which can compensate performance errors caused by gain change due to output voltage conversion, and maintain performance consistency under different gains, so that the design reliability of the power supply is improved.
The utility model adopts the technical scheme that:
in a first aspect, a compensation circuit is provided, and is applied to a switching power supply, and comprises a detection circuit, a subtraction circuit, an isolation operational amplifier circuit and a main control IC which are sequentially connected; the detection circuit is used for detecting an output voltage signal of the switching power supply and outputting a Va level signal after voltage division processing; the subtracting circuit is used for subtracting the Va level signal from the reference signal VREF to generate a Vb level signal which is inversely related to the Va level signal; the isolation operational amplifier circuit is used for amplifying the Vb level signal to generate a Vc level signal and outputting the Vc level signal to the COMP pin of the main control IC so that the main control IC compensates internally according to the Vc level signal.
Preferably, the detection circuit comprises a resistor R1 and a resistor R2, wherein one end of the resistor R1 is used as an input end of the detection circuit and is used for being connected with an output end of the switching power supply; the other end of the resistor R1 is connected with one end of the resistor R2 and then is used as the output end of the detection circuit to be connected with the input end of the subtraction circuit; the other end of the resistor R2 is grounded.
Preferably, the subtracting circuit includes a comparator U3, a resistor R3 and a resistor R4; one end of the resistor R3 is used as the input end of the subtraction circuit and is connected with the output end of the detection circuit; the other end of the resistor R3 is connected with one end of the resistor R4 and the reverse input end of the comparator U3; the positive input end of the comparator U3 is used for accessing a reference signal VREF; the other end of the resistor R4 is connected with the output end of the comparator U3, and then is used as the output end of the subtraction circuit and is connected with the input end of the isolation operational amplifier circuit.
Preferably, the isolation operational amplifier circuit is a dual operational amplifier IC including 8 pins.
Preferably, the master IC is model TEA9026T.
Preferably, the resistances of the resistor R1 and the resistor R2 are equal.
In a second aspect, there is provided a switching power supply comprising a main power circuit and a compensation circuit as described above; the input end of the compensation circuit is connected with the output end of the main power circuit and is used for detecting the output voltage of the main power circuit.
Compared with the prior art, the utility model has the beneficial effects that: the main control IC compensates the inside of the main control IC according to the output voltage, when the output voltage is higher, the voltage gain is higher, the COMP pin level of the main control IC is lower, low gain compensation is realized, when the output voltage is lower, the voltage gain is lower, the COMP pin level of the main control IC is higher, high gain compensation is realized, and compared with most traditional power supply ICs and digital IC schemes, the main control IC has fewer components and parts, simple circuit, and can reduce design cost and improve circuit reliability.
Drawings
Fig. 1 is a schematic diagram of a compensation circuit according to the present utility model.
Detailed Description
So that the manner in which the above recited objects, features and advantages of the present utility model can be understood in detail, a more particular description of the utility model, briefly summarized below, may be had by reference to embodiments, some of which are illustrated in the appended drawings. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present application.
It should be noted that the terms "comprising" and "having," and any variations thereof, as described in the specification and claims of this application are intended to cover a non-exclusive inclusion, for example, comprising a series of elements or unit circuits that are not necessarily limited to those elements or unit circuits explicitly listed, but may include elements or unit circuits that are not explicitly listed or inherent to such circuits.
It will be understood that, in the description and in the claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "connected" to the other element through a third element.
As shown in fig. 1, a schematic diagram of a compensation circuit according to the present embodiment is provided, in the present embodiment, a compensation circuit is provided and applied to a switching power supply, and the compensation circuit includes a detection circuit, a subtraction circuit, an isolation operational amplifier circuit and a main control IC, which are sequentially connected; the detection circuit is used for detecting an output voltage signal of the switching power supply and outputting a Va level signal after voltage division processing; the subtracting circuit is used for subtracting the Va level signal from the reference signal VREF to generate a Vb level signal which is inversely related to the Va level signal; the isolation operational amplifier circuit is used for amplifying the Vb level signal to generate a Vc level signal and outputting the Vc level signal to the COMP pin of the main control IC so that the main control IC compensates internally according to the Vc level signal.
As a specific implementation mode of the detection circuit, the detection circuit comprises a resistor R1 and a resistor R2, wherein one end of the resistor R1 is used as an input end of the detection circuit and is used for being connected with an output end of a switching power supply; the other end of the resistor R1 is connected with one end of the resistor R2 and then is used as the output end of the detection circuit to be connected with the input end of the subtraction circuit; the other end of the resistor R2 is grounded. In the implementation process of this embodiment, the resistance values of the resistor R1 and the resistor R2 are equal.
As a specific embodiment of the subtracting circuit, the subtracting circuit includes a comparator U3, a resistor R3 and a resistor R4; one end of the resistor R3 is used as the input end of the subtraction circuit and is connected with the output end of the detection circuit; the other end of the resistor R3 is connected with one end of the resistor R4 and the reverse input end of the comparator U3; the positive input end of the comparator U3 is used for accessing a reference signal VREF; the other end of the resistor R4 is connected with the output end of the comparator U3, and then is used as the output end of the subtraction circuit and is connected with the input end of the isolation operational amplifier circuit.
Specifically, the isolation operational amplifier circuit is a dual operational amplifier IC comprising 8 pins; the model of the master control IC is TEA9026T.
The working principle of the compensation circuit in this embodiment is as follows:
the resistor R1 and the resistor R2 of the detection circuit have the voltage division function, and the divided voltages are as follows:
as can be seen from the formula (1), va level becomes large when the output voltage VO becomes large;
the subtracting circuit comprises a comparator U3, a resistor R3 and a resistor R4, and uses the input end circuit and the feedback circuit to have equal current, namely the current of the branch where the resistor R3 is positioned is equal to the current of the branch where the resistor R4 is positioned, and the flowing current is that
The simplification can be obtained:
wherein VREF is the reference voltage VREF accessed by the positive input end of the comparator U3, and when the Va level becomes large, the Vb level becomes small as known by a formula;
the isolation operational amplifier circuit U1 has an input end for inputting a Vb level and an output end for outputting a Vc level, and the level relationship is as follows, assuming that the amplification coefficient is beta:
V c ＝β·V b ； (4)
as can be seen from the formula, when the Vb level becomes smaller, the Vc level becomes smaller;
the main control IC U2 detects the level change of Vc, and as can be seen from formulas (1) - (4), when the VO level becomes large, the Vc level becomes small; when the VO level becomes smaller, the Vc level becomes larger; therefore, when the output voltage is high, the voltage gain is high, the level of the main control IC U2 COMP pin is low, low-gain compensation is realized, when the output is low, the voltage gain is low, the level of the main control IC U2 COMP pin is high, and high-gain compensation is realized.
In another embodiment, a switching power supply is provided comprising a main power circuit and a compensation circuit as described above; the input end of the compensation circuit is connected with the output end of the main power circuit and is used for detecting the output voltage of the main power circuit.
The foregoing is illustrative of the preferred embodiments of the present utility model, and it should be noted that the foregoing is not to be construed as limiting the utility model, and that modifications and adaptations to those skilled in the art may be made without departing from the spirit and scope of the utility model, which is also intended to be covered by the appended claims.
Claims (7)
1. A compensation circuit is applied to a switching power supply and is characterized by comprising a detection circuit, a subtraction circuit, an isolation operational amplifier circuit and a main control IC which are connected in sequence; the detection circuit is used for detecting an output voltage signal of the switching power supply and outputting a Va level signal after voltage division processing; the subtracting circuit is used for subtracting the Va level signal from the reference signal VREF to generate a Vb level signal which is inversely related to the Va level signal; the isolation operational amplifier circuit is used for amplifying the Vb level signal to generate a Vc level signal and outputting the Vc level signal to the COMP pin of the main control IC so that the main control IC compensates internally according to the Vc level signal.
2. The compensation circuit according to claim 1, wherein the detection circuit comprises a resistor R1 and a resistor R2, and one end of the resistor R1 is used as an input end of the detection circuit and is used for being connected with an output end of a switching power supply; the other end of the resistor R1 is connected with one end of the resistor R2 and then is used as the output end of the detection circuit to be connected with the input end of the subtraction circuit; the other end of the resistor R2 is grounded.
3. The compensation circuit of claim 1, wherein the subtraction circuit comprises a comparator U3, a resistor R3, and a resistor R4; one end of the resistor R3 is used as the input end of the subtraction circuit and is connected with the output end of the detection circuit; the other end of the resistor R3 is connected with one end of the resistor R4 and the reverse input end of the comparator U3; the positive input end of the comparator U3 is used for accessing a reference signal VREF; the other end of the resistor R4 is connected with the output end of the comparator U3, and then is used as the output end of the subtraction circuit and is connected with the input end of the isolation operational amplifier circuit.
4. The compensation circuit of claim 1 wherein the isolated op-amp circuit is a dual op-amp IC comprising 8 pins.
5. The compensation circuit of claim 1, wherein the master IC is model TEA9026T.
6. The compensation circuit of claim 2, wherein the resistances of the resistor R1 and the resistor R2 are equal.
7. A switching power supply comprising a main power circuit and a compensation circuit as claimed in any one of claims 1 to 6; the input end of the compensation circuit is connected with the output end of the main power circuit and is used for detecting the output voltage of the main power circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321941943.5U CN220492857U (en) | 2023-07-21 | 2023-07-21 | Compensation circuit and switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321941943.5U CN220492857U (en) | 2023-07-21 | 2023-07-21 | Compensation circuit and switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220492857U true CN220492857U (en) | 2024-02-13 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321941943.5U Active CN220492857U (en) | 2023-07-21 | 2023-07-21 | Compensation circuit and switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220492857U (en) |
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2023
- 2023-07-21 CN CN202321941943.5U patent/CN220492857U/en active Active
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