CN115700975A - Control circuit and control method of switching power supply - Google Patents
Control circuit and control method of switching power supply Download PDFInfo
- Publication number
- CN115700975A CN115700975A CN202211408801.2A CN202211408801A CN115700975A CN 115700975 A CN115700975 A CN 115700975A CN 202211408801 A CN202211408801 A CN 202211408801A CN 115700975 A CN115700975 A CN 115700975A
- Authority
- CN
- China
- Prior art keywords
- triode
- power supply
- switching power
- voltage
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- 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
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention provides a control circuit and a control method of a switching power supply, belonging to the technical field of switching power supplies, wherein the control circuit comprises a controller, a current regulation circuit and a triangular carrier generator, wherein the control circuit comprises: the controller generates a first control signal according to the current operation parameter of the switching power supply; the current adjusting circuit receives the first control signal to respond to the first control signal and adjust the slope of the triangular carrier generated by the triangular carrier generator; the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply. According to the invention, the current operation parameters of the switching power supply are collected, the current adjusting circuit is controlled to adjust the slope of the triangular carrier, and the switching power supply is controlled to operate according to the adjusted triangular carrier, so that the defect of insufficient gain or disordered time sequence of the switching power supply caused by the limited slope of the triangular carrier is solved.
Description
Technical Field
The invention relates to the technical field of switching power supplies, in particular to a control circuit and a control method of a switching power supply.
Background
In a switching power supply, in order to realize quick response to input and output voltages, one or more of input voltage, output voltage, input current and output current are collected frequently, then a fixed capacitor is charged and discharged through a triangular carrier generator, and a formed triangular carrier is compared with the output of a voltage loop error amplifier to be used as a PWM (Pulse Width Modulation) wave to control the operation of the switching power supply.
The slope of the existing triangular carrier generator is limited by the supply voltage of a preceding stage controller, a voltage-controlled constant current source and the like, the charging current of a fixed capacitor can only change in a small range, and the slope of the triangular carrier can only change in a small range, so that the converter is difficult to work in an ultra-wide voltage input and ultra-wide voltage output range, the gain of the switching power supply is not enough or the time sequence is disordered, and the control of the switching power supply for ultra-wide voltage input and ultra-wide voltage output cannot be realized.
Disclosure of Invention
The invention provides a control circuit and a control method of a switching power supply, which are used for solving the defects that in the prior art, the charging current of a fixed capacitor can only be changed in a small range, the slope of a triangular carrier is limited, the gain of the switching power supply is insufficient or the time sequence is disordered, and the control of the switching power supply for ultra-wide voltage input and ultra-wide voltage output is difficult to realize.
The invention provides a control circuit of a switching power supply, which comprises a controller, a current adjusting circuit and a triangular carrier generator, wherein:
the controller generates a first control signal according to the current operation parameter of the switching power supply;
the current adjusting circuit receives the first control signal to respond to the first control signal and adjust the slope of the triangular carrier generated by the triangular carrier generator;
the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply.
According to a control circuit of a switching power supply provided by the present invention, the controller is configured to:
under the condition that the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value, generating the first control signal to adjust the working state of the current adjusting circuit so as to reduce the slope of the triangular carrier;
and generating the first control signal to adjust the working state of the current adjusting circuit so as to increase the slope of the triangular carrier when the input voltage of the switching power supply is greater than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is greater than a set threshold value.
According to the control circuit of the switching power supply, the triangular carrier generator comprises a voltage-controlled constant current source, a basic current mirror and a fixed capacitor, wherein the voltage-controlled constant current source is used for providing current for the basic current mirror, and the basic current mirror is connected with the fixed capacitor;
the current adjusting circuit comprises at least one resistance value adjusting unit and at least one change-over switch, and one change-over switch is connected with one resistance value adjusting unit;
each resistance value adjusting unit adjusts the charging current of the fixed capacitor by controlling the corresponding change-over switch;
the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
According to the control circuit of the switching power supply, the voltage-controlled constant current source comprises an operational amplifier and a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a plurality of fixed value resistors which are connected in series, and each fixed value resistor is connected with one of the change-over switches in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of one constant value resistor, the constant value resistors are connected in series and then grounded, and each constant value resistor is connected with one selector switch in parallel;
according to the control circuit of the switching power supply provided by the invention, the voltage-controlled constant current source comprises an operational amplifier and a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a plurality of fixed value resistors connected in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the fixed value resistor, each fixed value resistor is connected with one end of one selector switch, and the other end of the selector switch is grounded;
wherein at least one of the switches is closed.
According to the control circuit of the switching power supply provided by the invention, the voltage-controlled constant current source comprises an operational amplifier and a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a potentiometer;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the potentiometer, and the other end of the potentiometer is grounded;
the controller adjusts the resistance value of the potentiometer to adjust the charging current of the fixed capacitor.
According to the control circuit of the switching power supply, the triangular carrier generator comprises a voltage-controlled constant current source, a basic current mirror and a fixed capacitor;
the current regulation circuit comprises at least one additional current mirror output loop and at least one change-over switch; the change-over switch is connected with the additional current mirror output loop and used for adjusting the on-off of the additional current mirror output loop so as to adjust the charging current of the fixed capacitor;
the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
According to the control circuit of the switching power supply provided by the invention, the voltage-controlled constant current source comprises an operational amplifier and a first triode; the additional current mirror comprises a second triode and a third triode; the current regulation circuit comprises a plurality of additional current mirror output loops connected in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode is connected with the positive electrode of control voltage, the emitter of the third triode is connected with the positive electrode of the control voltage through the change-over switch, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, and a negative input pin of the operational amplifier is connected with an emitting electrode of the first triode in parallel and then grounded through a constant value resistor;
the controller controls the on and off of the change-over switch, and adjusts the on and off of the third triode and the positive electrode of the control voltage so as to adjust the charging current of the fixed capacitor.
The invention also provides a control method of the switching power supply, which is realized based on the control circuit and comprises the following steps:
acquiring an operating parameter of the switching power supply, and generating a first control signal in response to the operating parameter;
adjusting the slope of a triangular carrier generated by the triangular carrier generator according to the first control signal;
the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply.
According to the control method of the switching power supply provided by the invention, when the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than the set threshold value:
under the control of the first control signal, switching the working mode of the current adjusting circuit to increase the overall resistance of the current adjusting circuit;
reducing a charging current of the triangular carrier generator to reduce a slope of the triangular carrier;
when the input voltage of the switching power supply is larger than the output voltage of the switching power supply, and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value:
under the control of the first control signal, switching the working mode of the current adjusting circuit to reduce the overall resistance of the current adjusting circuit;
and increasing the charging current of the triangular carrier generator to increase the slope of the triangular carrier.
The invention also provides a switching power supply which comprises the control circuit.
According to the switching power supply provided by the invention, a main power circuit corresponding to the switching power supply is a step-up/step-down circuit or a step-up circuit;
and under the condition that the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value, the current adjusting circuit responds to the first control signal and reduces the slope of the triangular carrier generated by the triangular carrier generator.
According to the switching power supply provided by the invention, a main power circuit corresponding to the switching power supply is a step-up and step-down circuit or a step-down circuit;
and under the condition that the input voltage of the switching power supply is greater than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is greater than a set threshold value, the current adjusting circuit responds to the first control signal and increases the slope of the triangular carrier generated by the triangular carrier generator.
According to the control circuit and the control method of the switching power supply, the current operation parameters of the switching power supply are collected, the current adjusting circuit is controlled to adjust the slope of the triangular carrier, the switching power supply is controlled to operate according to the adjusted triangular carrier, and the defect that the gain of the switching power supply is insufficient or the time sequence is disordered due to the fact that the slope of the triangular carrier is limited is overcome.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 is a schematic block diagram of a control circuit of a switching power supply according to an embodiment of the present invention;
fig. 2 is one of schematic diagrams of a control circuit of a switching power supply according to an embodiment of the present invention;
fig. 3 is a second schematic diagram of a control circuit of a switching power supply according to an embodiment of the present invention;
fig. 4 is a third schematic diagram of a control circuit of a switching power supply according to an embodiment of the present invention;
fig. 5 is a fourth schematic diagram of a control circuit of a switching power supply according to an embodiment of the present invention;
fig. 6 is a flowchart illustrating a control method of a switching power supply according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the embodiments of the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected," "connected," and "electrically connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. Specific meanings of the above terms in the embodiments of the present invention can be understood in specific cases by those of ordinary skill in the art.
In embodiments of the invention, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an embodiment of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
When the switching power supply has an ultra-wide voltage input and an ultra-wide voltage output, the following problems may occur:
when the input voltage is smaller than the output voltage and the transformation ratio is gradually increased, the inductor excitation time is required to be continuously increased, and at the moment, if the charging current of the capacitor is kept constant, the output of the voltage loop error amplifier needs to be continuously increased until the clamping voltage is reached, so that the carrying capacity of the switching power supply is limited.
When the input voltage is greater than the output voltage and the transformation ratio is gradually increased, the inductor excitation time is required to be continuously reduced, and at the moment, if the charging current of the capacitor is kept constant and the output of the voltage loop error amplifier needs to be continuously reduced, the switching power supply can work intermittently, and the ripple wave is increased.
Fig. 1 is a schematic block diagram of a control circuit of a switching power supply according to an embodiment of the present invention, and referring to fig. 1, the present invention provides a control circuit of a switching power supply, including a controller 110, a current adjusting circuit 120, and a triangular carrier generator 130, wherein:
the controller 110 generates a first control signal according to the current operating parameter of the switching power supply;
the current adjusting circuit 120 receives the first control signal to adjust the slope of the triangular carrier generated by the triangular carrier generator 130 in response to the first control signal;
the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply.
Optionally, the current operating parameters of the switching power supply include, but are not limited to, system parameters such as input voltage, output voltage, input current, and output current, and the application voltage range is expanded without changing the topology structure.
Optionally, the current adjusting circuit 120 adjusts a slope of the triangular carrier generated by the triangular carrier generator 130 in response to the first control signal, specifically, the current adjusting circuit 120 adjusts a current of the triangular carrier generator 130, so as to adjust the slope of the triangular carrier.
Optionally, the triangular carrier and voltage loop error amplifier generates a second control signal, where the second control signal is a PWM wave and is used to control operation of the switching power supply.
It can be understood that, in the embodiment of the present invention, the current operating parameter of the switching power supply is collected, the current adjusting circuit is controlled to adjust the slope of the triangular carrier, and the switching power supply is controlled to operate according to the adjusted triangular carrier, so that the defect of insufficient gain or time sequence disorder of the switching power supply due to the limited slope of the triangular carrier is overcome.
On the basis of the above embodiment, as an optional embodiment, the controller is configured to:
under the condition that the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value, generating the first control signal to adjust the working state of the current adjusting circuit so as to reduce the slope of the triangular carrier;
and generating the first control signal to adjust the working state of the current adjusting circuit so as to increase the slope of the triangular carrier when the input voltage of the switching power supply is greater than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is greater than a set threshold value.
Optionally, adjusting the operating state of the current adjusting circuit to decrease the slope of the triangular carrier wave includes adjusting the operating state of the current adjusting circuit to decrease the charging current of the triangular carrier wave generator to decrease the slope of the triangular carrier wave.
Optionally, adjusting the operating state of the current adjusting circuit to increase the slope of the triangular carrier wave includes adjusting the operating state of the current adjusting circuit to increase the charging current of the triangular carrier wave generator to increase the slope of the triangular carrier wave.
It can be understood that, by configuring the operating mode of the controller, the embodiment of the invention can realize the control of the switching power supply with ultra-wide voltage input under the condition of ensuring that the intermittent operating mode of the switching power supply is not triggered and the load is not influenced.
On the basis of the above embodiment, as an optional embodiment, the triangular carrier generator includes a voltage-controlled constant current source, a basic current mirror and a fixed capacitor, the voltage-controlled constant current source is configured to provide a current for the basic current mirror, and the basic current mirror is connected to the fixed capacitor;
the current adjusting circuit comprises at least one resistance value adjusting unit and at least one change-over switch, and one change-over switch is connected with one resistance value adjusting unit;
each resistance value adjusting unit adjusts the charging current of the fixed capacitor by controlling the corresponding change-over switch;
the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
Optionally, the controller generates a first control signal for controlling the on/off or movement of the switch according to the current operating parameter of the switching power supply, and controls the switch based on the first control signal.
Optionally, the resistance adjusting unit is a potentiometer or a fixed resistance device, and if the resistance adjusting unit is a fixed resistance device, at least two or more resistance adjusting units are required, so that the overall resistance of the current adjusting circuit is adjusted by adjusting the series-parallel relationship of the fixed resistance devices or the number of the fixed resistance devices connected to the series-parallel circuit. If the resistance value adjusting unit is a potentiometer, the overall resistance value of the current adjusting circuit can be changed by adjusting the resistance value of the potentiometer.
It can be understood that the embodiment of the present invention provides a technical solution for changing the slope of the triangular carrier by using the change of the resistance value. Under the condition that the output of the voltage loop error amplifier continuously increases or continuously decreases, the charging current of the fixed capacitor needs to be adjusted, the voltage-controlled constant current source provides constant current, and the constant current passes through the current adjusting circuit and generates voltage change along with the change of the resistance value, so that the charging current of the fixed capacitor changes.
Fig. 2 is a schematic diagram of a control circuit of a switching power supply according to an embodiment of the present invention, and on the basis of the foregoing embodiment, as an alternative embodiment, as shown in fig. 2, the voltage-controlled constant current source includes an operational amplifier and a first triode; the current adjusting circuit comprises a plurality of fixed value resistors which are connected in series, and each fixed value resistor is connected with one of the change-over switches in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of one constant value resistor, the constant value resistors are connected in series and then grounded, and each constant value resistor is connected with one selector switch in parallel;
optionally, the positive pole of the control voltage is 5V.
It can be understood that, by closing the switch, the circuit scheme of the current regulation circuit provided in the embodiments of the present invention may reduce the overall resistance of the current regulation circuit, increase the charging current of the fixed capacitor, and increase the slope of the triangular carrier. When the change-over switch is turned on, the integral resistance value of the current adjusting circuit is increased, the charging current of the fixed capacitor is reduced, and the slope of the triangular carrier is reduced.
Fig. 3 is a second schematic diagram of the control circuit of the switching power supply according to the second embodiment of the present invention, and on the basis of the second embodiment, as an alternative embodiment, as shown in fig. 3, the voltage-controlled constant current source includes an operational amplifier and a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a plurality of fixed value resistors connected in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of a control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the fixed value resistor, each fixed value resistor is connected with one end of one selector switch, and the other end of each selector switch is grounded;
wherein at least one of the switches is closed.
It can be understood that the present invention provides another embodiment of the current adjusting circuit, if the switch is turned off, the resistance of the current adjusting circuit is decreased, and if the switch is turned on, the resistance of the current adjusting circuit is increased.
Fig. 4 is a third schematic diagram of a control circuit of a switching power supply according to an embodiment of the present invention, and based on the above embodiment, as an alternative embodiment, as shown in fig. 4, the voltage-controlled constant current source includes an operational amplifier and a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a potentiometer;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the potentiometer, and the other end of the potentiometer is grounded;
the controller adjusts the resistance value of the potentiometer to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
It can be understood that, the embodiment of the present invention provides a circuit scheme of a current adjusting circuit, which adjusts the resistance value of a potentiometer through a controller output signal, reduces the resistance value of the potentiometer, increases the charging current of a fixed capacitor, and increases the slope of a triangular carrier. Increasing the resistance of the potentiometer will reduce the charging current of the fixed capacitor, and the slope of the triangular carrier will decrease.
On the basis of the above embodiment, the current adjusting circuit may further be configured such that a plurality of parallel resistors are connected to a plurality of series resistors.
Based on the above embodiments, as an optional embodiment, when the input voltage of the switching power supply is smaller than the output voltage and the transformation ratio is gradually increased, the inductor excitation time is required to be continuously increased, and on the basis that the output of the voltage loop error amplifier does not trigger the intermittent operation, the slope of the triangular carrier needs to be continuously reduced, that is, the capacitor charging current i is reduced C And i is C ＝U/R s Wherein U is the input voltage of the voltage-controlled constant current source, R s The sampling resistor is a voltage-controlled constant current source. When R is increased with the increase of the transformation ratio s When the voltage-controlled constant current source input voltage and/or the output voltage of the preceding-stage digital controller exceed the lower precision limit, the sampling resistor R is increased by the controller s The voltage-controlled constant-current source input voltage and the digital controller output voltage are increased in equal proportion on the basis of unchanged charging current.
When the input voltage of the switching power supply is greater than the output voltage and the transformation ratio is gradually increased, the required inductor excitation time is continuously reduced, and on the basis that the output of the voltage loop error amplifier is not clamped, the slope of the triangular carrier needs to be continuously increased, namely the charging current i of the fixed capacitor is increased C And i is C ＝U/R s Wherein U is a voltage-controlled constant current source input voltage, R s The sampling resistor of the voltage-controlled constant current source, the maximum value of the input voltage of the voltage-controlled constant current source and the maximum value of the output voltage of the digital controller are the respective power supply voltages. When R is increased with the increase of the transformation ratio s When the voltage-controlled constant current source input voltage and/or the output voltage of the preceding-stage digital controller exceed the power supply voltage, the sampling resistor R is reduced by the controller s The voltage-controlled constant current source input voltage is proportionally reduced on the basis of unchanged charging current.
It can be understood that the embodiment of the invention can continuously reduce the charging current of the capacitor and avoid the limitation of the carrying capacity of the switching power supply; by continuously increasing the fixed capacitor for charging, the switching power supply does not intermittently work and does not increase ripples.
Fig. 5 is a fourth schematic diagram of the principle of the control circuit of the switching power supply according to an embodiment of the present invention, and on the basis of the above embodiment, as an alternative embodiment, as shown in fig. 5, the triangular carrier generator includes a voltage-controlled constant current source, a basic current mirror, and a fixed capacitor;
the current regulation circuit comprises at least one additional current mirror output loop and at least one change-over switch; the change-over switch is connected with the additional current mirror output loop and used for adjusting the on-off of the additional current mirror output loop so as to adjust the charging current of the fixed capacitor;
the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
It can be understood that the embodiment of the present invention adjusts the charging current of the fixed capacitor by adjusting the output loop of the additional current mirror.
On the basis of the above embodiment, as an optional embodiment, the voltage-controlled constant current source includes an operational amplifier and a first triode; the additional current mirror output loop comprises a second triode and a third triode; the current regulation circuit comprises a plurality of additional current mirror output loops connected in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode is connected with the positive electrode of control voltage, the emitter of the third triode is connected with the positive electrode of the control voltage through the change-over switch, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, and a negative input pin of the operational amplifier is connected with an emitting electrode of the first triode in parallel and then grounded through a constant value resistor;
the controller controls the on and off of the change-over switch, and adjusts the on and off of the third triode and the positive electrode of the control voltage so as to adjust the charging current of the fixed capacitor.
It can be understood that, after the switch is turned on, the additional current mirror output circuit does not provide current for the fixed capacitor any more, and after the switch is turned off, the additional current mirror output circuit provides current for the fixed capacitor, and the larger the number of the additional current mirror output circuits is, the larger the charging current of the fixed capacitor is.
On the basis of the above embodiment, as an optional embodiment, the switching power supply further includes a voltage-controlled constant current source and a fixed capacitor, the current adjusting circuit includes at least one resistance value adjusting unit and a plurality of additional current mirror output loops, the voltage-controlled constant current source is respectively connected to the resistance value adjusting unit and the additional current mirror output loops, the additional current mirror output loops are connected to the fixed capacitor, each resistance value adjusting unit and each additional current mirror output loop are respectively connected to a switch, and the operating mode of the resistance value adjusting unit and the on/off of the additional current mirror output loops are adjusted by the switches.
Optionally, the voltage-controlled constant current source includes an operational amplifier and a first triode; the current adjusting circuit comprises a potentiometer; the additional current mirror output loop comprises a second triode and a third triode;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the potentiometer, and the other end of the potentiometer is grounded;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode is connected with the positive electrode of control voltage, the emitter of the third triode is connected with the positive electrode of the control voltage through the change-over switch, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
the controller is used for adjusting the resistance value of the potentiometer so as to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier;
the controller is further used for controlling the on and off of the change-over switch and adjusting the on and off of the third triode and the positive electrode of the control voltage so as to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
Optionally, the voltage-controlled constant current source includes an operational amplifier and a first triode; the current adjusting circuit comprises a plurality of fixed-value resistors connected in series; the additional current mirror output loop comprises a second triode and a third triode;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of one constant value resistor, the constant value resistors are connected in series and then grounded, and each constant value resistor is connected with one selector switch in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode is connected with the positive electrode of control voltage, the emitter of the third triode is connected with the positive electrode of the control voltage through the change-over switch, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
the controller is used for adjusting the integral resistance value of the current adjusting circuit by adjusting the opening and closing of the change-over switch so as to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier;
the controller is further used for controlling the on and off of the change-over switch and adjusting the on and off of the third triode and the positive electrode of the control voltage so as to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier; at least one of the switches is closed.
Optionally, the voltage-controlled constant current source includes an operational amplifier and a first triode; the current adjusting circuit comprises a plurality of fixed value resistors connected in parallel; the additional current mirror output loop comprises a second triode and a third triode;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the fixed value resistor, each fixed value resistor is connected with one end of one selector switch, and the other end of each selector switch is grounded;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode is connected with the positive electrode of control voltage, the emitter of the third triode is connected with the positive electrode of the control voltage through the change-over switch, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
the controller is used for adjusting the integral resistance value of the current adjusting circuit by adjusting the opening and closing of the change-over switch so as to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier, wherein at least one of the switches is closed;
the controller is further used for controlling the on and off of the change-over switch and adjusting the on and off of the third triode and the positive electrode of the control voltage so as to adjust the charging current of the fixed capacitor; the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier; at least one of the switches is closed.
It can be understood that the embodiment of the present invention provides a technical solution for adjusting the slope of the triangular carrier by combining the resistance adjustment circuit and the additional current mirror output loop, which solves the technical defect that the slope of the triangular carrier is limited.
On the basis of the above embodiment, as an optional embodiment, the current operating parameters of the switching power supply include:
and one or more parameters of input voltage, output voltage, input current and output current of the switching power supply.
It can be understood that the controller collects the input voltage, the output voltage, the input current and the output current I of the switching power supply o And generating a switch on/off or potentiometer control signal according to the collected parameters.
The following describes a control method of the switching power supply provided by the present invention, and the control method of the switching power supply described below and the control circuit of the switching power supply described above may be referred to in correspondence with each other.
Fig. 6 is a schematic flowchart of a control method of a switching power supply according to an embodiment of the present invention; referring to fig. 6, the present invention further provides a control method of a switching power supply, which is implemented based on the control circuit, and the control method includes:
s610, acquiring operation parameters of the switching power supply, and generating a first control signal in response to the operation parameters;
s620, adjusting the slope of the triangular carrier generated by the triangular carrier generator according to the first control signal;
and S630, the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply.
It can be understood that the control method provided by the embodiment of the present invention controls the current adjusting circuit to adjust the slope of the triangular carrier by acquiring the current operating parameter of the switching power supply, and controls the switching power supply to operate according to the adjusted triangular carrier, thereby solving the defect of insufficient gain or time sequence disorder of the switching power supply due to the limited slope of the triangular carrier.
On the basis of the above embodiment, as an optional embodiment, when the input voltage of the switching power supply is smaller than the output voltage of the switching power supply, and the transformation ratio value of the input voltage to the output voltage is larger than a set threshold:
under the control of the first control signal, switching the working mode of the current adjusting circuit to increase the overall resistance of the current adjusting circuit;
reducing a charging current of the triangular carrier generator to reduce a slope of the triangular carrier;
when the input voltage of the switching power supply is larger than the output voltage of the switching power supply, and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value:
under the control of the first control signal, switching the working mode of the current regulating circuit to reduce the overall resistance of the current regulating circuit;
and increasing the charging current of the triangular carrier generator to increase the slope of the triangular carrier.
It can be understood that the embodiment of the invention can realize the switch power supply control of the ultra-wide voltage input and the ultra-wide voltage output under the condition of ensuring that the intermittent working mode of the switch power supply is not triggered and the load is not influenced.
The following describes the switching power supply provided by the present invention, and the switching power supply described below and the control circuit of the switching power supply described above may be referred to correspondingly.
The invention also provides a switching power supply which comprises the control circuit.
On the basis of the above embodiment, as an optional embodiment, if the main power circuit corresponding to the switching power supply is a buck-boost circuit or a boost circuit, under the condition that the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio of the input voltage to the output voltage is greater than a set threshold, if the charging voltage of the fixed capacitor reaches the input voltage minimum limit of the voltage-controlled constant current source, the controller controls the switch to switch the operating mode of the current adjusting circuit, so as to reduce the charging current of the voltage-controlled constant current source to the fixed capacitor.
Optionally, if the main power circuit corresponding to the switching power supply is a buck-boost circuit or a buck circuit, under the condition that the input voltage of the switching power supply is greater than the output voltage of the switching power supply and the transformation ratio of the input voltage to the output voltage is greater than a set threshold, if the charging voltage of the fixed capacitor reaches the maximum limit of the input voltage of the voltage-controlled constant current source, the controller is utilized to control the switch to switch the operating mode of the current adjusting circuit, so as to increase the charging current of the voltage-controlled constant current source to the fixed capacitor.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (13)
1. A control circuit of a switching power supply is characterized by comprising a controller, a current adjusting circuit and a triangular carrier generator, wherein:
the controller generates a first control signal according to the current operation parameter of the switching power supply;
the current adjusting circuit receives the first control signal to respond to the first control signal and adjust the slope of the triangular carrier generated by the triangular carrier generator;
the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply.
2. The control circuit of the switching power supply according to claim 1, wherein the controller is configured to:
under the condition that the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value, generating the first control signal to adjust the working state of the current adjusting circuit so as to reduce the slope of the triangular carrier;
and generating the first control signal to adjust the working state of the current adjusting circuit so as to increase the slope of the triangular carrier when the input voltage of the switching power supply is greater than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is greater than a set threshold value.
3. The control circuit of the switching power supply according to claim 1, wherein the triangular carrier generator comprises a voltage-controlled constant current source, a base current mirror and a fixed capacitor, the voltage-controlled constant current source is used for providing current for the base current mirror, and the base current mirror is connected with the fixed capacitor;
the current adjusting circuit comprises at least one resistance value adjusting unit and at least one change-over switch, and one change-over switch is connected with one resistance value adjusting unit;
each resistance value adjusting unit adjusts the charging current of the fixed capacitor by controlling the corresponding change-over switch;
the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
4. The control circuit of the switching power supply according to claim 3, wherein: the voltage-controlled constant current source comprises an operational amplifier and a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a plurality of fixed value resistors which are connected in series, and each fixed value resistor is connected with one of the change-over switches in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
the output pin of the operational amplifier is connected with the base electrode of the first triode, the negative input pin of the operational amplifier and the emitter electrode of the first triode are both connected with one end of one constant value resistor, the constant value resistors are connected in series and then grounded, and each constant value resistor is connected with one selector switch in parallel.
5. The control circuit of the switching power supply according to claim 3, wherein the voltage-controlled constant current source comprises an operational amplifier, a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a plurality of fixed value resistors connected in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the fixed value resistor, each fixed value resistor is connected with one end of one selector switch, and the other end of the selector switch is grounded;
wherein at least one of the switches is closed.
6. The control circuit of the switching power supply according to claim 3, wherein the voltage-controlled constant current source comprises an operational amplifier, a first triode; the basic current mirror comprises a second triode and a third triode; the current adjusting circuit comprises a potentiometer;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode and the emitter of the third triode are both connected with the positive electrode of the control voltage, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, a negative input pin of the operational amplifier and an emitting electrode of the first triode are both connected with one end of the potentiometer, and the other end of the potentiometer is grounded;
the controller adjusts the resistance value of the potentiometer to adjust the charging current of the fixed capacitor.
7. The control circuit of the switching power supply according to claim 1, wherein the triangular carrier generator includes a voltage-controlled constant current source, a base current mirror, and a fixed capacitor;
the current regulation circuit comprises at least one additional current mirror output loop and at least one change-over switch; the change-over switch is connected with the additional current mirror output loop and used for adjusting the on-off of the additional current mirror output loop so as to adjust the charging current of the fixed capacitor;
the charging current of the fixed capacitor is positively correlated with the slope of the triangular carrier.
8. The control circuit of the switching power supply according to claim 7, wherein the voltage-controlled constant current source comprises an operational amplifier, a first triode; the additional current mirror output loop comprises a second triode and a third triode; the current regulation circuit comprises a plurality of additional current mirror output loops connected in parallel;
the collector and the base of the second triode are both connected with the collector of the first triode, the base of the second triode is connected with the base of the third triode, the emitter of the second triode is connected with the positive electrode of control voltage, the emitter of the third triode is connected with the positive electrode of the control voltage through the change-over switch, the collector of the third triode is connected with one end of the fixed capacitor, and the other end of the fixed capacitor is grounded;
an output pin of the operational amplifier is connected with a base electrode of the first triode, and a negative input pin of the operational amplifier is connected with an emitting electrode of the first triode in parallel and then grounded through a constant value resistor;
the controller controls the on and off of the change-over switch, and adjusts the on-off between the third triode and the positive electrode of the control voltage so as to adjust the charging current of the fixed capacitor.
9. A control method of a switching power supply, implemented based on the control circuit of any one of claims 1 to 8, the control method comprising:
acquiring an operating parameter of the switching power supply, and generating a first control signal in response to the operating parameter;
adjusting the slope of a triangular carrier generated by the triangular carrier generator according to the first control signal;
the triangular carrier is used for generating a second control signal for controlling the operation of the switching power supply.
10. The control method of the switching power supply according to claim 9, characterized in that: when the input voltage of the switching power supply is smaller than the output voltage of the switching power supply, and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value:
under the control of the first control signal, switching the working mode of the current adjusting circuit to increase the overall resistance of the current adjusting circuit;
reducing a charging current of the triangular carrier generator to reduce a slope of the triangular carrier;
when the input voltage of the switching power supply is larger than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value:
under the control of the first control signal, switching the working mode of the current adjusting circuit to reduce the overall resistance of the current adjusting circuit;
and increasing the charging current of the triangular carrier generator to increase the slope of the triangular carrier.
11. A switching power supply comprising a control circuit as claimed in any one of claims 1 to 8.
12. The switching power supply according to claim 11, wherein: the main power circuit corresponding to the switching power supply is a boost circuit or a booster circuit;
and under the condition that the input voltage of the switching power supply is smaller than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is larger than a set threshold value, the current adjusting circuit responds to the first control signal and reduces the slope of the triangular carrier generated by the triangular carrier generator.
13. The switching power supply according to claim 11, wherein the main power circuit corresponding to the switching power supply is a buck-boost circuit or a buck-boost circuit;
and under the condition that the input voltage of the switching power supply is greater than the output voltage of the switching power supply and the transformation ratio value of the input voltage and the output voltage is greater than a set threshold value, the current adjusting circuit responds to the first control signal and increases the slope of the triangular carrier generated by the triangular carrier generator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211408801.2A CN115700975A (en) | 2022-11-11 | 2022-11-11 | Control circuit and control method of switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211408801.2A CN115700975A (en) | 2022-11-11 | 2022-11-11 | Control circuit and control method of switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115700975A true CN115700975A (en) | 2023-02-07 |
Family
ID=85121237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211408801.2A Pending CN115700975A (en) | 2022-11-11 | 2022-11-11 | Control circuit and control method of switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115700975A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118092571A (en) * | 2024-04-23 | 2024-05-28 | 成都芯正微电子科技有限公司 | Portable programmable direct-current linear power supply generating circuit with variable slope |
| CN118100644A (en) * | 2024-04-23 | 2024-05-28 | 成都芯正微电子科技有限公司 | Direct-current linear power supply generating circuit with variable wide voltage and falling slope |
| CN118092570A (en) * | 2024-04-23 | 2024-05-28 | 成都芯正微电子科技有限公司 | Direct-current linear power supply generating circuit with wide voltage and variable rising slope |
-
2022
- 2022-11-11 CN CN202211408801.2A patent/CN115700975A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118092571A (en) * | 2024-04-23 | 2024-05-28 | 成都芯正微电子科技有限公司 | Portable programmable direct-current linear power supply generating circuit with variable slope |
| CN118100644A (en) * | 2024-04-23 | 2024-05-28 | 成都芯正微电子科技有限公司 | Direct-current linear power supply generating circuit with variable wide voltage and falling slope |
| CN118092570A (en) * | 2024-04-23 | 2024-05-28 | 成都芯正微电子科技有限公司 | Direct-current linear power supply generating circuit with wide voltage and variable rising slope |
| CN118092570B (en) * | 2024-04-23 | 2024-07-02 | 成都芯正微电子科技有限公司 | Direct-current linear power supply generating circuit with wide voltage and variable rising slope |
| CN118100644B (en) * | 2024-04-23 | 2024-07-09 | 成都芯正微电子科技有限公司 | Direct-current linear power supply generating circuit with variable wide voltage and falling slope |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115700975A (en) | Control circuit and control method of switching power supply | |
| US7372239B2 (en) | Multi-output type DC/DC converter | |
| US11594971B2 (en) | Control circuit and control method for switching regulator | |
| US20120133345A1 (en) | Hysteretic power converter with calibration circuit | |
| KR20100047159A (en) | Circuits and methods for power conversion | |
| US9819276B2 (en) | Power supply circuit using DC/DC converter | |
| CN102386771B (en) | Controller, current control method and DC-DC converter | |
| JP2006501798A (en) | Switching DC-DC power converter and battery charger for use with a direct oxidation fuel cell power supply | |
| JP2003033005A (en) | Switched-capacitor stabilized power supply | |
| KR20060049753A (en) | Power supply using step-down converter of synchronous rectifying manner | |
| CN112821762B (en) | Control circuit and booster circuit | |
| US8988039B2 (en) | Power converter circuit | |
| CN116436293A (en) | Hybrid control circuit and control method of switching power supply and switching power supply | |
| JP6134312B2 (en) | Downconverter control circuit and vehicle lamp | |
| US7154252B2 (en) | Converter for electronic flashlight | |
| US20130241660A1 (en) | Buck Up Power Converter | |
| CN112688540A (en) | Switching power converter and boost turn-off time adaptive adjusting unit | |
| JP2024525932A (en) | Driver for supplying current to an LED load | |
| CN115242060A (en) | Electromagnetic actuator control circuit, control method and medical equipment | |
| CN117856033A (en) | Constant current driving circuit, laser pumping source and laser radar | |
| CN113629994A (en) | Bidirectional multilevel converter topological structure for controlling battery energy storage system | |
| JP3863663B2 (en) | Amplifier circuit | |
| CN118157484B (en) | New energy circuit and new energy socket suitable for multiple loads | |
| CN217693087U (en) | Combination control voltage converter, power and new energy automobile | |
| CN216819411U (en) | Charging box and circuit thereof, and wireless earphone assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |