CN111146928A - Regulating circuit and BUCK circuit - Google Patents

Regulating circuit and BUCK circuit Download PDF

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Publication number
CN111146928A
CN111146928A CN202010065026.XA CN202010065026A CN111146928A CN 111146928 A CN111146928 A CN 111146928A CN 202010065026 A CN202010065026 A CN 202010065026A CN 111146928 A CN111146928 A CN 111146928A
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CN
China
Prior art keywords
switch
control unit
voltage
unit
load
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Pending
Application number
CN202010065026.XA
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Chinese (zh)
Inventor
李强
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Shenzhen Huliangyuan Technology Co Ltd
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Shenzhen Huliangyuan Technology Co Ltd
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Priority to CN202010065026.XA priority Critical patent/CN111146928A/en
Publication of CN111146928A publication Critical patent/CN111146928A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0009—Devices or circuits for detecting current in a converter
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0016—Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters
    • H02M1/0019—Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters the disturbance parameters being load current fluctuations
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0016—Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters
    • H02M1/0022—Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters the disturbance parameters being input voltage fluctuations

Abstract

The invention relates to a regulating circuit and a BUCK circuit, wherein the regulating circuit comprises an input voltage sampling unit, a logic control unit, a switch control unit and a load current detection unit; the input voltage sampling unit, the switch control unit and the load current detection unit are respectively connected with the logic control unit, the switch control unit is used for being connected with the control end of the switch tube, the output end of the switch tube is used for being connected with the load circuit unit, the input voltage value can be judged, and meanwhile, the state of the switch tube is controlled by combining the load state, so that the load dynamic response capability of the power supply can be effectively improved, the load circuit unit can adapt to a wider input voltage range, suitable input voltage can be provided for a post converter of the load circuit unit, the loss and temperature rise of the whole load circuit unit are finally reduced, and the reliability of the load circuit unit is improved.

Description

Regulating circuit and BUCK circuit
Technical Field
The invention relates to the field of circuits, in particular to a regulating circuit and a BUCK circuit.
Background
In the existing BUCK circuit, because the actual duty ratio of a PWM chip is little or can not reach 100%, only a relatively low BUCK output voltage can be selected, and only a post converter can adapt to the low voltage, under the condition, a switching tube is switched under the condition of low voltage and large current, and the loss of the BUCK circuit is relatively large; when the BUCK circuit is under high voltage, the duty ratio of the BUCK circuit is small, and the loss is large, so that the BUCK circuit and a corresponding post-stage circuit cannot work in the optimal state, the temperature rise of the whole circuit is large, the whole efficiency is low, and the reliability of the circuit is influenced.
Disclosure of Invention
In view of this, the present invention provides an adjusting circuit and a BUCK circuit, which can determine an input voltage value, and control a state of a switching tube in combination with a load state, and when a sampled voltage signal is smaller than a first preset voltage threshold, control the switching tube to be in a normally-on state, so that an output voltage value at this stage is not too low, and at this time, the switching tube is normally-on, and there is no switching loss, so that efficiency can be improved, and meanwhile, an input voltage of a rear-stage converter is improved, a variation range is relatively narrowed, and the rear-stage converter is easier to operate in an optimal state; furthermore, when the sampled voltage signal is not less than the first preset voltage threshold and not more than the second preset voltage threshold, it is further required to further determine whether the load current is greater than the preset current threshold according to the current detection signal, when the load current is greater than the preset current threshold, the switch control unit controls the switch tube to be in a normally-on state, at this time, the load circuit unit is equivalent to heavy load, the switch tube is in a long-time conducting state, at this time, the output voltage of the front-stage BUCK circuit can be increased, the switching loss is reduced, the efficiency is improved, a higher voltage can be output to the rear-stage converter, the current stress of the rear-stage converter is reduced, and simultaneously the duty ratio or the switching frequency can be further optimized to improve the efficiency at this stage, when the load current is not greater than the preset current threshold, the switch tube is operated in a high-frequency switching state, and the output voltage is normally, the post converter can work in a relatively ideal state; when the sampled voltage signal is greater than the second preset voltage threshold value, the switching tube works in a high-frequency switching state, and in the adjusting process, because a load participates in adjustment, the load dynamic response capability of the power supply can be effectively improved, so that the load circuit unit can adapt to a wider input voltage range, a proper input voltage can be provided for the post converter, the loss and the temperature rise of the whole load circuit unit are finally reduced, and the reliability of the load circuit unit is improved.
A regulation circuit comprising: the device comprises an input voltage sampling unit, a logic control unit, a switch control unit and a load current detection unit; the input voltage sampling unit, the switch control unit and the load current detection unit are respectively connected with the logic control unit, the switch control unit is used for being connected with the control end of the switch tube, and the output end of the switch tube is used for being connected with the load circuit unit;
the input voltage sampling unit is used for carrying out partial pressure sampling on input voltage and sending a voltage signal after the partial pressure sampling to the logic control unit;
the logic control unit is used for judging whether the voltage signal after partial pressure sampling is smaller than a first preset voltage threshold value or not, if so, generating a first switch driving control signal and sending the first switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a normally-on state;
the logic control unit is also used for judging that the voltage signal after the partial pressure sampling is larger than a second preset voltage threshold value, if so, generating a second switch driving control signal and sending the second switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a high-frequency switch state, and the second preset voltage threshold value is larger than the first preset voltage threshold value;
the load current detection unit is used for detecting the load current of the load circuit unit, generating a corresponding current detection signal and sending the current detection signal to the logic control unit;
the logic control unit is further used for judging whether the load current is larger than a preset current threshold value or not according to the current detection signal when the voltage signal after voltage division sampling is not smaller than the first preset voltage threshold value and not larger than the second preset voltage threshold value, if yes, generating a first switch driving control signal and sending the first switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a normally-on state, and if not, generating a second switch driving control signal and sending the second switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a high-frequency switch state.
In one embodiment, the logic control unit includes a first voltage comparator and a second voltage comparator, wherein an inverting input terminal of the first voltage comparator is connected to the input voltage sampling unit, a non-inverting input terminal of the first voltage comparator is connected to an output terminal of the second voltage comparator, and a non-inverting input terminal of the second voltage comparator is connected to the load current detection unit.
In one embodiment, the switch control unit comprises an optical coupler, a PWM controller and a switch driving module, wherein a positive input end of the optical coupler is connected to the logic control unit, a negative input end of the optical coupler is connected to a negative electrode of an input voltage through a first current-limiting resistor, a negative output end of the optical coupler is connected to the switch driving module, a negative output end of the optical coupler is connected to the PWM controller through a second current-limiting resistor, a positive output end of the optical coupler is externally connected to a reference power supply, and the switch driving module is further configured to be connected to a control end of the switching tube.
In one embodiment, the switch driving module adopts an NPN triode and a PNP triode, bases of the NPN triode and the PNP triode are respectively connected to a negative output end of the optocoupler, emitters of the NPN triode and the PNP triode are respectively connected to a control end of the switch tube, a collector of the NPN triode is externally connected to the reference power supply, and a collector of the PNP triode is connected to the load circuit unit.
In one embodiment, the switch driving module employs an IC chip.
In one embodiment, the logic control unit adopts a logic control chip.
In one embodiment, the input voltage sampling unit includes a first voltage dividing resistor and a second voltage dividing resistor connected in series, one end of the first voltage dividing resistor is externally connected with the input voltage, and the other end of the first voltage dividing resistor is connected with the logic control unit.
In one embodiment, the resistance value of the first voltage-dividing resistor is smaller than the resistance value of the second voltage-dividing resistor.
A BUCK circuit comprises a switch tube and a load circuit unit, wherein the output end of the switch tube is used for being connected with the load circuit unit, and the control end of the switch tube is connected with an adjusting circuit.
In one embodiment, the switching tube is any one of a triode, a MOS tube and an IGBT tube.
The regulating circuit comprises an input voltage sampling unit, a logic control unit, a switch control unit and a load current detection unit; the input voltage sampling unit, the switch control unit and the load current detection unit are respectively connected with the logic control unit, the switch control unit is used for being connected with the control end of the switch tube, the output end of the switch tube is used for being connected with the load circuit unit, the input voltage value can be judged, the state of the switch tube is controlled by combining the load state, when the sampled voltage signal is smaller than a first preset voltage threshold value, the switch tube is controlled to be in a normally-on state, so that the output voltage value at the stage is not too low, the switch tube is normally-on at the moment, no switching loss exists, the efficiency can be improved, meanwhile, the input voltage of a rear-stage converter connected with the load circuit unit is improved, the change range is relatively narrow, and the rear-stage converter is easier to work in an optimal state; furthermore, when the sampled voltage signal is not less than the first preset voltage threshold and not more than the second preset voltage threshold, it is further required to further determine whether the load current is greater than the preset current threshold according to the current detection signal, when the load current is greater than the preset current threshold, the switch control unit controls the switch tube to be in a normally-on state, at this time, the load circuit unit is equivalent to a heavy load, the switch tube is in a long-time conducting state, at this time, the output voltage of the load circuit unit can be increased, the switching loss is reduced, the efficiency is improved, a higher voltage can be provided for a later converter of the load circuit unit, the current stress of the later converter is reduced, and simultaneously, the duty ratio or the switching frequency can be further optimized to improve the efficiency at this stage, when the load current is not greater than the preset current threshold, the switch tube is operated in a high-frequency switching state, the output voltage is normally output, and the post converter can work in a relatively ideal state; when the sampled voltage signal is greater than the second preset voltage threshold value, the switching tube works in a high-frequency switching state, and in the adjusting process, because a load participates in adjustment, the load dynamic response capability of the power supply can be effectively improved, so that the load circuit unit can adapt to a wider input voltage range, a proper input voltage can be provided for a post converter of the load circuit unit, the loss and the temperature rise of the whole load circuit unit are finally reduced, and the reliability of the load circuit unit is improved.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention. Like components are numbered similarly in the various figures.
FIG. 1 is a schematic diagram of a regulating circuit provided in one embodiment;
fig. 2 is a circuit configuration diagram of a regulating circuit provided in one embodiment.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
Various embodiments of the present disclosure will be described more fully hereinafter. The present disclosure is capable of various embodiments and of modifications and variations therein. However, it should be understood that: there is no intention to limit the various embodiments of the disclosure to the specific embodiments disclosed herein, but rather, the disclosure is to cover all modifications, equivalents, and/or alternatives falling within the spirit and scope of the various embodiments of the disclosure.
Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present invention, are only intended to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present invention belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments of the present invention.
Fig. 1 is a block diagram of a regulating circuit 100 provided in one embodiment, the regulating circuit 100 including: the input voltage sampling unit 110, the logic control unit 120, the switch control unit 130 and the load current detection unit 140, wherein the input voltage sampling unit 110, the switch control unit 130 and the load current detection unit 140 are respectively connected with the logic control unit 120, the switch control unit 130 is used for being connected with a control end of a switch tube Q1, and an output end of the switch tube Q1 is used for being connected with the load circuit unit 150;
the input voltage sampling unit 110 is configured to perform voltage division sampling on an input voltage, and send a voltage signal after the voltage division sampling to the logic control unit 120;
the logic control unit 120 is configured to determine whether the voltage signal after voltage division sampling is smaller than a first preset voltage threshold, and if so, generate a first switch driving control signal and send the first switch driving control signal to the switch control unit 130 so that the switch control unit 130 controls the switching tube Q1 to be in a normally-on state;
the logic control unit 120 is further configured to determine that the voltage signal after the voltage division sampling is greater than a second preset voltage threshold, if so, generate a second switch driving control signal and send the second switch driving control signal to the switch control unit 130 so that the switch control unit 130 controls the switching tube Q1 to be in a high-frequency switching state, where the second preset voltage threshold is greater than the first preset voltage threshold;
the load current detection unit 140 is configured to detect a load current of the load circuit unit 150, generate a corresponding current detection signal, and send the current detection signal to the logic control unit 120;
the logic control unit 120 is further configured to, when the voltage signal after voltage division sampling is not less than the first preset voltage threshold and not greater than the second preset voltage threshold, determine whether the load current is greater than the preset current threshold according to the current detection signal, if so, generate a first switch driving control signal and send the first switch driving control signal to the switch control unit 130 so that the switch control unit 130 controls the switch tube Q1 to be in a normally-on state, and if not, generate a second switch driving control signal and send the second switch driving control signal to the switch control unit 130 so that the switch control unit 130 controls the switch tube Q1 to be in a high-frequency switch state.
The above-mentioned regulating circuit includes an input voltage sampling unit 110, a logic control unit 120, a switch control unit 130 and a load current detection unit 140; the input voltage sampling unit 110, the switch control unit 130 and the load current detection unit 140 are respectively connected to the logic control unit 120, the switch control unit 130 is used for being connected to the control end of the switching tube Q1, the output end of the switching tube Q1 is used for being connected to the load circuit unit 150, the input voltage value can be judged, and the state of the switching tube Q1 is controlled by combining the load state, when the sampled voltage signal is smaller than the first preset voltage threshold value, the switching tube Q1 is controlled to be in a normally-on state, so that the output voltage value at this stage is not too low, at this time, the switching tube Q1 is normally-on, there is no switching loss, and the efficiency can be improved, and at the same time, the input voltage of the post-stage converter connected to the load circuit unit 150 is improved, the change range is relatively narrowed, and the post-stage converter is easier to operate in an optimal state.
Further, when the sampled voltage signal is not less than the first preset voltage threshold and not more than the second preset voltage threshold, it is further required to determine whether the load current is greater than the preset current threshold according to the current detection signal, when the load current is greater than the preset current threshold, the switch control unit 130 controls the switching tube Q1 to be in a normally-on state, at this time, the load circuit unit 150 is equivalent to a heavy load, and the switching tube Q1 is in a long-time conducting state, at this time, the output voltage of the load circuit unit 150 can be increased, the switching loss is reduced, the efficiency is improved, a higher voltage can be provided for the subsequent converter of the load circuit unit 150, the current stress of the subsequent converter is reduced, and meanwhile, the duty ratio or the switching frequency can be further optimized to improve the efficiency at this stage; when the load current is not greater than the preset current threshold, the switching tube Q1 works in a high-frequency switching state, the output voltage is normally output, and the post-stage converter can work in a relatively ideal state; when the sampled voltage signal is greater than the second preset voltage threshold, the switching tube Q1 works in a high-frequency switching state, and in the above adjusting process, because of the participation of the load in the adjustment, the load dynamic response capability of the power supply can be effectively improved, so that the load circuit unit 150 can adapt to a wider input voltage range, and a suitable input voltage can be provided for the subsequent converter of the load circuit unit 150, thereby finally reducing the loss and temperature rise of the whole load circuit unit 150 and improving the reliability of the load circuit unit 150.
In one embodiment, the logic control unit 120 includes a first voltage comparator 122 and a second voltage comparator 124, wherein an inverting input terminal of the first voltage comparator 122 is connected to the input voltage sampling unit 110, a non-inverting input terminal of the first voltage comparator 122 is connected to an output terminal of the second voltage comparator 124, and a non-inverting input terminal of the second voltage comparator 124 is connected to the load current detection unit 140.
In one embodiment, the switch control unit 130 includes an optical coupler P1, a PWM controller 132, and a switch driving module 134, wherein a positive input terminal of the optical coupler P1 is connected to the logic control unit 120, a negative input terminal of the optical coupler P1 is connected to a negative terminal of an input voltage through a first current limiting resistor R1, a negative output terminal of the optical coupler P1 is connected to the switch driving module 134, a negative output terminal of the optical coupler P1 is connected to the PWM controller 132 through a second current limiting resistor R2, a positive output terminal of the optical coupler P1 is externally connected to a reference power supply, and the switch driving module 134 is further configured to be connected to a control terminal of the switching tube Q1.
The optical coupler P1 can be replaced by other isolation devices with the same function.
In one embodiment, the non-inverting input terminal of the first voltage comparator 122 is externally connected to the reference voltage through a resistor R3, the output terminal of the second voltage comparator 124 is connected to the non-inverting input terminal of the first voltage comparator 122 through a third current limiting resistor R4, and the non-inverting input terminal of the second voltage comparator 124 is externally connected to the load current detection unit 140 through a pull-down resistor R5.
In one embodiment, the switch driving module 134 employs an NPN transistor Q2 and a PNP transistor Q3, bases of the NPN transistor Q2 and the PNP transistor Q3 are respectively connected to a negative output terminal of the optocoupler P1, emitters of the NPN transistor Q2 and the PNP transistor Q3 are respectively connected to a control terminal of the switch transistor Q1, a collector of the NPN transistor Q2 is externally connected to the reference power supply, and a collector of the PNP transistor Q3 is connected to the load circuit unit 150.
In one embodiment, the switch driving module 134 employs an IC chip.
In one embodiment, the logic control unit 120 employs a logic control chip.
In one embodiment, the input voltage sampling unit 110 includes a first voltage dividing resistor R6 and a second voltage dividing resistor R7 connected in series, one end of the first voltage dividing resistor R6 is externally connected to the input voltage, and the other end of the first voltage dividing resistor R6 is connected to the logic control unit 120.
In one embodiment, the resistance value of the first divider resistor R6 is less than the resistance value of the second divider resistor R7.
In one embodiment, as shown in fig. 2, the switch Q1 and the load circuit unit 150 form a BUCK circuit, and the load circuit unit 150 includes an inductor L, a capacitor C, and a diode D1.
In one embodiment, a BUCK circuit is provided, the BUCK circuit includes a switch Q1 and a load circuit unit 150, an output terminal of the switch Q1 is used for connecting with the load circuit unit 150, and a control terminal and an input terminal of the switch Q1 are respectively connected with the above-mentioned regulating circuit 100.
In one embodiment, the switching tube Q1 adopts any one of a triode, a MOS tube and an IGBT tube.
In the embodiment shown in fig. 2, the output value of the second voltage comparator 124 is used to provide a reference voltage for the first voltage comparator 122, wherein when the load current is greater than the preset current threshold I, it indicates that the load circuit unit 150 is overloaded, at this time, the second voltage comparator 124 outputs the first reference voltage VREF1, when the voltage signal sampled by the input voltage sampling unit 110 is not less than the first preset voltage threshold and not greater than the second preset voltage threshold, at this time, the second voltage comparator 124 outputs the first reference voltage VREF1 (high level), the first voltage comparator 122 outputs high level (corresponding to the second switch driving control signal), the optocoupler switch P1 is in a normally-on state, and drives the NPN Q2 to be turned on to drive the switching tube Q1 to operate, at this time, the output voltage of the load circuit unit 150 can be increased, and the switching loss can be reduced, the efficiency is improved, and a higher voltage can be supplied to the subsequent converter of the load circuit unit 150, the current stress of the subsequent converter is reduced, and the duty ratio or the switching frequency can be further optimized to improve the efficiency at this stage.
Further, when the load current is not greater than the preset current threshold I, the second voltage comparator 124 outputs the second reference voltage VREF2, when the voltage signal sampled by the input voltage sampling unit 110 is less than the first preset voltage threshold, P1 is turned off, Q2 does not work, the PWM controller 132 controls the PNP transistor Q3 to operate, so that the switching tube Q1 operates in a high-frequency switching state, the output voltage is normally output, and at this time, the post-stage converter can operate in a more ideal state.
When the sampled voltage signal is greater than the second preset voltage threshold, no matter whether the first reference voltage VREF1 or the second reference voltage VREF2 is provided, the switching tube Q1 is controlled by the PWM controller 132, and the switching tube Q3 is turned on and operates in a high-frequency switching state.
In the adjusting process, because the load participates in the adjustment, the load dynamic response capability of the power supply can be effectively improved, so that the load circuit unit 150 can adapt to a wider input voltage range, and can provide a proper input voltage for the subsequent converter of the load circuit unit 150, thereby finally reducing the loss and the temperature rise of the whole load circuit unit 150 and improving the reliability of the load circuit unit 150.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented in other ways. The above-described apparatus embodiments are merely illustrative.
In addition, each functional module or unit in each embodiment of the present invention may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention.

Claims (10)

1. A regulation circuit, characterized in that the regulation circuit comprises: the device comprises an input voltage sampling unit, a logic control unit, a switch control unit and a load current detection unit; the input voltage sampling unit, the switch control unit and the load current detection unit are respectively connected with the logic control unit, the switch control unit is used for being connected with the control end of the switch tube, and the output end of the switch tube is used for being connected with the load circuit unit;
the input voltage sampling unit is used for carrying out partial pressure sampling on input voltage and sending a voltage signal after the partial pressure sampling to the logic control unit;
the logic control unit is used for judging whether the voltage signal after the partial pressure sampling is smaller than a first preset voltage threshold value or not, if so, generating a first switch driving control signal and sending the first switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a normally-on state;
the logic control unit is further used for judging that the voltage signal after the partial pressure sampling is larger than a second preset voltage threshold value, if so, generating a second switch driving control signal and sending the second switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a high-frequency switch state, and the second preset voltage threshold value is larger than the first preset voltage threshold value;
the load current detection unit is used for detecting the load current of the load circuit unit, generating a corresponding current detection signal and sending the current detection signal to the logic control unit;
the logic control unit is further used for judging whether the load current is larger than a preset current threshold value according to the current detection signal when the voltage signal after the partial pressure sampling is not smaller than the first preset voltage threshold value and not larger than the second preset voltage threshold value, if so, generating a first switch driving control signal and sending the first switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a normally-on state, and if not, generating a second switch driving control signal and sending the second switch driving control signal to the switch control unit so that the switch control unit controls the switch tube to be in a high-frequency switch state.
2. The regulating circuit according to claim 1, wherein the logic control unit comprises a first voltage comparator and a second voltage comparator, an inverting input terminal of the first voltage comparator is connected to the input voltage sampling unit, a non-inverting input terminal of the first voltage comparator is connected to an output terminal of the second voltage comparator, and a non-inverting input terminal of the second voltage comparator is connected to the load current detection unit.
3. The regulating circuit according to claim 1, wherein the switch control unit comprises an optocoupler, a PWM controller and a switch driving module, an anode input end of the optocoupler is connected to the logic control unit, a cathode input end of the optocoupler is connected to a cathode of the input voltage through a first current limiting resistor, a cathode output end of the optocoupler is connected to the switch driving module, a cathode output end of the optocoupler is connected to the PWM controller through a second current limiting resistor, an anode output end of the optocoupler is externally connected to a reference power supply, and the switch driving module is further configured to be connected to a control end of the switching tube.
4. The adjusting circuit according to claim 3, wherein the switch driving module employs an NPN triode and a PNP triode, bases of the NPN triode and the PNP triode are respectively connected with a negative output end of the optocoupler, emitters of the NPN triode and the PNP triode are respectively connected with a control end of the switch tube, a collector of the NPN triode is externally connected with the reference power supply, and a collector of the PNP triode is connected with the load circuit unit.
5. The regulating circuit according to claim 3, wherein the switch driving module is an IC chip.
6. The regulating circuit according to claim 1, wherein the logic control unit is a logic control chip.
7. The adjusting circuit of claim 1, wherein the input voltage sampling unit comprises a first voltage dividing resistor and a second voltage dividing resistor connected in series, one end of the first voltage dividing resistor is externally connected to the input voltage, and the other end of the first voltage dividing resistor is connected to the logic control unit.
8. The adjusting circuit of claim 7, wherein the first voltage-dividing resistor has a resistance value smaller than a resistance value of the second voltage-dividing resistor.
9. BUCK circuit, characterized in that the BUCK circuit comprises a switching tube and a load circuit unit, the output end of the switching tube is used for being connected with the load circuit unit, and the control end of the switching tube is connected with the regulating circuit of any one of claims 1-8.
10. The BUCK circuit according to claim 9, wherein the switching tube is any one of a triode, an MOS tube and an IGBT tube.
CN202010065026.XA 2020-01-20 2020-01-20 Regulating circuit and BUCK circuit Pending CN111146928A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112837646A (en) * 2021-02-02 2021-05-25 海信视像科技股份有限公司 Display device and control method thereof
CN113258912A (en) * 2021-04-29 2021-08-13 珠海格力电器股份有限公司 Control device and method of switch tube and electrical equipment
CN114488873A (en) * 2021-12-24 2022-05-13 深圳市联洲国际技术有限公司 Control circuit and device
CN116599346A (en) * 2023-07-17 2023-08-15 广州中基国威电子科技有限公司 Load driving circuit, method and electronic equipment

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112837646A (en) * 2021-02-02 2021-05-25 海信视像科技股份有限公司 Display device and control method thereof
CN112837646B (en) * 2021-02-02 2022-12-06 海信视像科技股份有限公司 Display device and control method thereof
CN113258912A (en) * 2021-04-29 2021-08-13 珠海格力电器股份有限公司 Control device and method of switch tube and electrical equipment
CN113258912B (en) * 2021-04-29 2024-05-03 珠海格力电器股份有限公司 Control device and method of switching tube and electrical equipment
CN114488873A (en) * 2021-12-24 2022-05-13 深圳市联洲国际技术有限公司 Control circuit and device
CN114488873B (en) * 2021-12-24 2024-05-03 深圳市联洲国际技术有限公司 Control circuit and device
CN116599346A (en) * 2023-07-17 2023-08-15 广州中基国威电子科技有限公司 Load driving circuit, method and electronic equipment
CN116599346B (en) * 2023-07-17 2023-10-13 广州中基国威电子科技有限公司 Load driving circuit, method and electronic equipment

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