Switching power supply circuit, power supply system and electronic equipment

Abstract

The embodiment of the invention provides a switching power supply circuit, a power supply system and electronic equipment, the switching power supply circuit comprises a switching impedance module, a feedback module, an inductive current detection module, a slope compensation module and a control module, and the switching impedance module comprises a first inductor, a first capacitor and at least one first switch; the feedback module is used for outputting an error signal according to the second voltage and preset reference voltage; the inductive current detection module is used for outputting an initial ramp signal according to the rising current of the first inductor; the slope compensation module is used for outputting a ramp compensation signal according to the current drop slope of the first inductor; the control module is used for outputting a control signal according to the error signal and the target ramp signal. The slope compensation module can output the slope self-adaptive change oblique wave compensation signal, and for different input voltages, output voltages or inductors, the self-adaptive change oblique wave compensation signal can avoid the under-compensation or over-compensation phenomenon.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a switching power supply circuit, a power supply system and an electronic device. Background Art

[0002] A DC-to-DC converter is a switching power supply circuit that can convert a DC power supply into a DC power supply of different voltages, so it can meet the power supply requirements of circuit modules with different supply voltages. At present, among various types of DC-to-DC converters, the DC-to-DC converter with a peak current control mode is the most widely used in practice because it has the advantages of fast response speed and no need for a lead compensation network compared to the DC-to-DC converter with a voltage control mode.

[0003] In the related art, the DC-DC converter of the peak current control mode mainly includes a switching circuit, a voltage feedback loop and a current feedback loop, and controls the switching circuit in a dual feedback manner of voltage and current. Among them, in the current feedback loop, in order to avoid the occurrence of subharmonic oscillation when the duty cycle of the feedback control signal is greater than 50%, a slope compensation circuit is usually set. However, the traditional slope compensation circuit adopts a fixed slope compensation signal slope. When the input voltage, output voltage or inductance size changes, the fixed slope compensation slope may cause the DC-DC converter to be under-compensated or over-compensated, which in turn causes the DC-DC converter to have subharmonic oscillation phenomenon or change to voltage mode control mode, which will cause the advantages of current mode control to be lost, and in severe cases will affect the efficiency or dynamic performance of the DC-DC converter. Summary of the invention

[0004] In view of the above problems, the embodiments of the present application provide a switching power supply circuit, a power supply system and an electronic device to solve the above technical problems.

[0005] In a first aspect, an embodiment of the present application provides a switching power supply circuit, comprising:

[0006] A switch impedance module, the switch impedance module includes a first inductor, a first capacitor and at least one first switch, the switch impedance module is used to access the first voltage and output a second voltage under the control of the control signal on the first switch;

[0007] A feedback module, the feedback module is used to output an error signal according to the second voltage and a preset reference voltage;

[0008] An inductor current detection module, the inductor current detection module is used to output an initial ramp signal according to the rising current of the first inductor;

[0009] A slope compensation module, the slope compensation module is used to output a slope compensation signal according to the current falling slope of the first inductor to compensate the initial slope signal and generate a target slope signal;

[0010] A control module, the control module is used to output a control signal according to the error signal and the target ramp signal;

[0011] The slope of the ramp compensation signal changes with the current falling slope of the first inductor.

[0012] In a second aspect, an embodiment of the present application further provides a power supply system, comprising the above-mentioned switching power supply circuit.

[0013] In a third aspect, an embodiment of the present application further provides an electronic device, comprising the above-mentioned power supply system or switching power supply circuit.

[0014] The present application outputs an error signal according to the second voltage and the preset reference voltage through the feedback module, and uses the initial ramp signal of the ramp compensation signal output by the slope compensation module to compensate and generate a target ramp signal, so that the control module can output a control signal according to the error signal and the target ramp signal, and finally realize the dual-loop peak current feedback control of the voltage and current of the switch impedance module. At the same time, since the ramp compensation signal is based on the current drop slope of the first inductor, and the absolute value of the ratio between the slope of the ramp compensation signal and the current drop slope of the first inductor is greater than 0.5, the slope compensation module can output a ramp compensation signal whose slope follows the current drop slope of the first inductor. When the input voltage, output voltage or inductance changes, the ramp compensation signal whose slope follows the current drop slope of the first inductor can avoid under-compensation or over-compensation in the switching power supply circuit, thereby solving the problem that the fixed slope ramp compensation signal has subharmonic oscillation phenomenon or changes to voltage mode control mode when the input voltage, output voltage or inductance changes.

[0015] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of a DC-DC converter in the related art is shown.

[0018] Figure 2A schematic diagram showing the change of the ideal inductor current and the actual inductor current when the duty cycle of the feedback control signal PWM is less than 50%.

[0019] Figure 3 A schematic diagram showing the change of the ideal inductor current and the actual inductor current when the duty cycle of the feedback control signal PWM is greater than 50%.

[0020] Figure 4 Another schematic diagram showing the changes of the ideal inductor current and the actual inductor current when the duty cycle of the feedback control signal PWM is greater than 50%.

[0021] Figure 5 A schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0022] Figure 6 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0023] Figure 7 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0024] Figure 8 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0025] Fig. 9 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0026] Fig.10 A schematic diagram of an inductor current detection module in an embodiment of the present application is shown.

[0027] Fig.11 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0028] Fig.12 A schematic diagram showing relevant signals in a switching power supply circuit in an embodiment of the present application is shown.

[0029] Fig.13 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0030] Fig.14 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0031] Fig.15 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0032] Fig.16 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0033] Fig.17 A schematic diagram of a compensation signal output unit in an embodiment of the present application is shown.

[0034] Among them, 10 is a switch impedance module, 20 is a feedback module, 30 is an inductor current detection module, 40 is a slope compensation module, 41 is a compensation adjustment unit, 411 is an analog-to-digital converter, 412 is a rising slope logic calculation unit, 413 is an inductor logic calculation unit, 414 is a falling slope logic calculation unit, 42 is a compensation signal output unit, and 50 is a control module;

[0035] A first inductor L1, a first capacitor C1, and a first switch S1;

[0036] control signal Vc, first voltage AVDD, second voltage VBST, preset reference voltage Vref, error signal Vea, initial ramp signal Isense, ramp compensation signal Islope, target ramp signal Vramp, compensation adjustment signal Dout;

[0037] A first current source IS1, a first transistor M1, a second transistor M2, a second capacitor C2, a second switch S2, a third resistor R3, a third transistor M3, a fourth transistor M4, a first resistor R1, a second resistor R2, a first operational amplifier OP, and a first comparator COMP. DETAILED DESCRIPTION

[0038] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0039] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0040] In the embodiments of the present application, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0041] Moreover, the terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0042] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0043] In addition, the "plurality" in the embodiments of the present application refers to two or more than two. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C can be included.

[0044] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0045] The first pole / first end of each transistor used in the embodiments of the present application is one of the source and the drain, and the second pole / second end of each transistor is the other of the source and the drain. Since the source and drain of the transistor can be symmetrical in structure, the source and drain thereof can be structurally indistinguishable, that is, the first pole / first end and the second pole / second end of the transistor in the embodiments of the present application can be structurally indistinguishable. Exemplarily, in the case where the transistor is a P-type transistor, the first pole / first end of the transistor is the source, and the second pole / second end is the drain; exemplarily, in the case where the transistor is an N-type transistor, the first pole / first end of the transistor is the drain, and the second pole / second end is the source.

[0046] In the circuit structure provided in the embodiments of the present application, the first node, the second node and other nodes do not represent actual existing components, but represent the junction points of related couplings in the circuit diagram, that is, these nodes are nodes formed by the equivalent junction points of related couplings in the circuit diagram.

[0047] At present, the peak current control mode DC-DC converter is the most widely used switching power supply. Figure 1 , Figure 1 A schematic diagram of a DC-DC converter in the related art is shown, wherein the DC-DC converter includes a BOOST boost circuit and a feedback control circuit for controlling the BOOST boost circuit, wherein the BOOST boost circuit is composed of an inductor L0, a diode D0, a voltage-stabilizing capacitor C0 and a transistor MN1, and the feedback control circuit is composed of a current detection circuit, a ramp compensation circuit, a resistor R03, a feedback resistor R01, a feedback resistor R02, an operational amplifier OP, a comparator COMP and an RS trigger, so as to control the transistor MN1 in the BOOST boost circuit through the feedback control circuit, and enable the BOOST boost circuit to output a boosted output voltage Vout according to the input voltage VDD voltage.

[0048] In the feedback control circuit, the inverting input terminal of the operational amplifier OP is connected between the feedback resistor R01 and the feedback resistor R02, the non-inverting input terminal of the operational amplifier OP is connected to the reference voltage Vref, the feedback resistor R01, the feedback resistor R02 and the operational amplifier OP form a voltage feedback loop, so the voltage feedback loop can output the error signal Verror to the non-inverting input terminal of the comparator COMP; the current detection circuit can output the amplified current signal I1 during the current rise period of the inductor L0, the slope compensation circuit can output the compensation current signal I2, and finally the amplified current signal I1 and the compensation current signal I2 are superimposed and pass through the resistor R03 to generate the ramp signal Vra, and the ramp signal Vra is input to the inverting input terminal of the comparator, and finally a dual-loop feedback control circuit of the voltage loop and the current loop is formed, and the feedback control signal PWM is output through the comparator COMP and the RS trigger connected to the clock signal LCK.

[0049] For a DC-DC converter in peak current control mode, subharmonic oscillation is a common phenomenon in switching power supplies that use peak current control mode. Subharmonic oscillation generally does not occur when the duty cycle of the feedback control signal PWM is less than 50%, but mainly occurs when the duty cycle of the feedback control signal PWM is greater than 50%. When subharmonic oscillation occurs, if the inductor current has a small fluctuation, the circuit fluctuation will increase in the next cycle.

[0050] For example, see Figure 2 , Figure 2shows a schematic diagram of the change in the ideal inductor current and the actual inductor current when the PWM duty cycle of the feedback control signal is less than 50%. In Figure 2 the solid line is the ideal current of inductor L0, the dashed line is the actual current of inductor L0, and ΔI0 is the error current caused by the influence of the external environment on the current of inductor L0 in the previous cycle. After one cycle, the error current ΔI1 of the inductor current satisfies the following relationship:

[0051] ΔI1 = -ΔI0 * k2 / k1

[0052] where k1 is the rising slope of the inductor current and k2 is the falling slope of the inductor current.

[0053] Since the PWM duty cycle of the feedback control signal is less than 50%, it can be known that k2 < k1. Therefore, ΔI1 is less than ΔI0. After several cycles, the error current converges, so it will not cause sub-harmonic oscillation.

[0054] When the PWM duty cycle of the feedback control signal is greater than 50%, if the ramp compensation circuit is not used for ramp compensation, refer to Figure 3 , Figure 3 shows a schematic diagram of the change in the ideal inductor current and the actual inductor current when the PWM duty cycle of the feedback control signal is greater than 50%. After one cycle, the error current ΔI1 of the inductor current satisfies the following relationship:

[0055] ΔI1 = -ΔI0 * k2 / k1

[0056] Since the PWM duty cycle of the feedback control signal is greater than 50%, it can be known that k2 > k1. Therefore, ΔI1 is greater than ΔI0. After several cycles, the error current diverges, so it will eventually cause sub-harmonic oscillation.

[0057] To avoid the occurrence of sub-harmonic oscillation when the duty cycle of the feedback control signal is greater than 50%, the DC-DC converter usually sets a ramp compensation circuit. As Figure 1 shown, the ramp compensation circuit can output a compensation current signal I2. Finally, the amplified current signal I1 and the compensation current signal I2 are superimposed and pass through the resistor R03 to generate a ramp signal Vra. If the voltage corresponding to the compensation current signal I2 is equivalently applied to the error signal Verror, the change in the ideal current of inductor L0 and the actual current of inductor L0 is as Figure 4 shown. After ramp compensation, the error signal Verror is equivalently superimposed with a sawtooth wave compensation signal (corresponding to the compensation current signal I2). The slope of the sawtooth wave compensation signal is k. It can be known that after one cycle, the error current ΔI1 of the inductor current satisfies the following relationship:

[0058] ΔI1 = -ΔI0 * (k2 - k) / (k1 + k)

[0059] It can be seen that when k>1 / 2*k2, (k2-k) / (k1+k) in the above formula is always a decimal less than 1, so ΔI1 is less than ΔI0. After several cycles, the error current converges, thus solving the subharmonic oscillation phenomenon caused by the duty cycle of the feedback control signal PWM being greater than 50%.

[0060] However, the conventional slope compensation circuit adopts a fixed slope of the ramp compensation signal (i.e., the slope k of the sawtooth compensation signal is a fixed value). When any one of the input voltage, the output voltage or the inductance changes, the fixed slope compensation slope may cause the DC-DC converter to be under-compensated or over-compensated, thereby causing the DC-DC converter to have subharmonic oscillation or change to a voltage mode control mode, which will lead to the loss of the advantages of the current mode control and, in severe cases, will affect the efficiency or dynamic performance of the DC-DC converter.

[0061] To this end, the present application provides a switching power supply circuit, a power supply system and an electronic device, which are described in detail below.

[0062] First, see Figure 5 , Figure 5 A schematic diagram of a switching power supply circuit in an embodiment of the present application is shown, wherein the switching power supply circuit includes a switching impedance module 10, a feedback module 20, an inductor current detection module 30, a slope compensation module 40 and a control module 50.

[0063] Specifically, the switch impedance module 10 is used to access the first voltage AVDD, and output the second voltage VBST under the control of the control signal Vc on the first switch S1. The second voltage VBST may be greater than the first voltage AVDD, or the second voltage VBST may be less than the first voltage AVDD. For example, the switch impedance module 10 may include a BOOST boost circuit so that the switch impedance module 10 outputs a second voltage VBST with a higher voltage according to the first voltage AVDD; for another example, the switch impedance module 10 may include a BUCK buck circuit so that the switch impedance module 10 outputs a second voltage VBST with a lower voltage according to the first voltage AVDD.

[0064] It should be noted that the switch impedance module 10 includes a first inductor L1, a first capacitor C1 and at least one first switch S1, and the connection method of the first inductor L1, the first capacitor C1 and the at least one first switch S1 is different in the BOOST circuit and the BUCK circuit.

[0065] For example, taking the BOOST boost circuit as an example, refer to Figure 6 , Figure 6Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, wherein the first end of the first inductor L1 is connected to the first voltage AVDD, the first end of the first switch S1 is connected to the second end of the first inductor L1, the second end of the first switch S1 is connected to the ground, the control end of the first switch S1 is connected to the control signal Vc, the first end of the first diode D1 is connected to the second end of the first inductor L1, the first end of the first capacitor C1 is connected to the second end of the first diode D1, the second end of the first capacitor C1 is connected to the ground, and the first end of the first capacitor C1 outputs the second voltage VBST.

[0066] When the control signal Vc controls the first switch S1 to be turned on, the first voltage AVDD charges the first inductor L1, the current of the first inductor L1 gradually increases, the first diode D1 is in a cut-off state, and the first capacitor C1 discharges to output the second voltage VBST; when the control signal Vc controls the first switch S1 to be turned off, the first inductor L1 is discharged and the current gradually decreases, the first diode D1 is in a turned-on state, the first voltage AVDD is superimposed on the induced electromotive force of the first inductor L1, and since the induced electromotive force of the first inductor L1 is in the same direction as the first voltage AVDD, a second voltage VBST with a higher voltage can be output.

[0067] For another example, taking the BUCK step-down circuit as an example, refer to Figure 7 , Figure 7 Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, where the first end of the first switch S1 is connected to the first voltage AVDD, the second end of the first switch S1 is connected to the first end of the first inductor L1, the second end of the first inductor L1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the ground, the first end of the first capacitor C1 outputs the second voltage VBST, the first end of the first diode D1 is connected to the first end of the first inductor L1, and the second end of the first diode D1 is connected to the ground.

[0068] When the control signal Vc controls the first switch S1 to be disconnected, the first inductor L1 is discharged and the current gradually decreases, the first diode D1 is in the on state, and the first capacitor C1 is discharged to output the second voltage VBST; when the control signal Vc controls the first switch S1 to be turned on, the first inductor L1 is charged and the current gradually increases, the first diode D1 is in the off state, and the first voltage AVDD is superimposed on the induced electromotive force of the first inductor L1. Since the induced electromotive force of the first inductor L1 is in the opposite direction to the first voltage AVDD, a second voltage VBST with a lower voltage can be output.

[0069] Understandably, the above Figure 6 as well as Figure 7As only an exemplary embodiment of the switch impedance module 10 of the present application, those skilled in the art can make equivalent modifications and designs to the switch impedance module under the guidance of the present application. For example, the switch impedance module 10 can also include a Buck-Boost step-up and step-down circuit; for another example, refer to Figure 8 , Figure 8 Another schematic diagram of the switching power supply circuit in the embodiment of the present application is shown. In the above embodiment, the first diode D1 can also be replaced by a switch S1', and the control signal Vc is only needed to be inverted and input into the control end of the switch S1'.

[0070] The feedback module 20 is used to output the error signal Vea according to the second voltage VBST and the preset reference voltage Vref to form a voltage feedback loop in the peak current control mode. In some embodiments of the present application, for example, for an embodiment in which the switch impedance module 10 includes a BUCK step-down circuit, the feedback module 20 can use an operational amplifier to output the error signal Vea according to the second voltage VBST and the preset reference voltage Vref. In some embodiments of the present application, for example, for an embodiment in which the switch impedance module 10 includes a BOOST step-up circuit, the feedback module 20 can use a resistor divider circuit and an operational amplifier to output the error signal Vea according to the second voltage VBST and the preset reference voltage Vref.

[0071] For example, taking the switch impedance module 10 including a BOOST boost circuit as an example, refer to Fig. 9 , Fig. 9 Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, wherein the feedback module 20 includes a first resistor R1, a second resistor R2 and a first operational amplifier OP; the first end of the first resistor R1 is used to access the second voltage VBST, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the ground end; the first input end of the first operational amplifier OP is connected to the first node mo1 between the first resistor R1 and the second resistor R2, the second input end of the first operational amplifier OP is used to access the preset reference voltage Vref, and the output end of the first operational amplifier OP is used to output the error signal Vea.

[0072] It should be noted that, due to the virtual short and virtual open characteristics of the first operational amplifier OP, the error signal Vea output by the first operational amplifier OP can be used to feedback and adjust the size of the second voltage VBST. After the feedback loop is stable, the voltages of the first input terminal and the second input terminal of the first operational amplifier OP are equal. Therefore, the second voltage VBST and the preset reference voltage Vref satisfy the relationship: VBST = Vref*(R1+R2) / R2, thereby realizing negative feedback regulation of the voltage of the switching power supply circuit.

[0073] The inductor current detection module 30 is used to output an initial ramp signal Isense according to the rising current of the first inductor L1, so as to realize the current negative feedback regulation of the switching power supply circuit. In some embodiments of the present application, the inductor current detection module 30 can mirror the rising current of the first inductor L1 and output the initial ramp signal Isense as a current signal, and the ratio of the rising current of the first inductor L1 to the initial ramp signal Isense is 1:1. In some embodiments of the present application, the inductor current detection module 30 can amplify the rising current signal of the first inductor L1 to obtain the amplified initial ramp signal Isense, and the ratio of the rising current of the first inductor L1 to the initial ramp signal Isense is 1:N, N>1.

[0074] As an example, see Fig.10 , Fig.10 A schematic diagram of the inductor current detection module 30 in the embodiment of the present application is shown, wherein the inductor current detection module 30 includes a current source IS01, a current source IS02, transistors M01-M06 and resistors R01-R03, the second end of the transistor M01 is connected to one end of the first inductor L1 to access the rising current Iin of the first inductor L1, the control end of the transistor M01 is connected to the control signal Vc, the first end of the transistor M01 is connected to the first end of the resistor R01, and the second end of the resistor R01 is connected to the ground end; the input end of the current source IS01 is connected to the power supply end VDD, the output end of the current source IS01 is connected to the second end of the transistor M02, the control end of the transistor M02 is connected to the control end of the transistor M03, the first end of the transistor M02 is connected to the first end of the resistor R02, and the second end of the resistor R02 is connected to the first end of the resistor R01; An input end of the current source IS02 is connected to the power supply end VDD, an output end of the current source IS02 is connected to the second end of the transistor M03, the second end of the transistor M03 is connected to the control end of the transistor M03, a first end of the transistor M03 is connected to the first end of the resistor R03, and a second end of the resistor R03 is connected to the ground end; a first end of the transistor M05 is connected to the power supply end VDD, a control end of the transistor M05 is connected to the second end of the transistor M05, a second end of the transistor M05 is connected to the first end of the transistor M04, a control end of the transistor M04 is connected to the second end of the transistor M02, and a first end of the transistor M04 is connected to the first end of the resistor R03; a first end of the transistor M06 is connected to the power supply end VDD, a control end of the transistor M06 is connected to the control end of the transistor M05, and a second end of the transistor M06 is used to output an initial ramp signal Isense.

[0075] Specifically, in Fig.10 In the example, the source voltage of transistor M02 and the source voltage of transistor M03 can be calculated according to the following formula:

[0076] VS2=I01*R02+(Iin+I01)*R01

[0077] VS3=I02*R03+I_M04*R03

[0078] Among them, VS2 is the source voltage of the transistor M02, VS3 is the source voltage of the transistor M03, Iin is the inductor current, I01 is the current output by the current source IS01, I02 is the current output by the current source IS02, and I_M04 is the output current of the transistor M04.

[0079] Since transistor M02 and transistor M03 are current mirrors with a mirror ratio of 1:1, VS2 = VS3. At the same time, since I01 is much smaller than Iin and R01 is much smaller than R02, the term I01*R01 can be ignored. According to VS2 = VS3, the following formula can be obtained:

[0080] I01*R02+Iin*R01=I02*R03+I_M04*R03

[0081] When the currents output by the current sources IS01 and IS02 are equal, and the resistance values ​​of the resistors R02 and R03 are equal, it can be seen that the current flowing through the transistor M04 satisfies the following relationship:

[0082] I M04 = Iin * R01 / R02

[0083] At the same time, since the current mirror flowing through the transistor M05 is equal to the current flowing through the transistor M04, and the transistor M05 and the transistor M06 are current mirrors of each other, assuming that the mirror ratio between the transistor M05 and the transistor M06 is 1, the second end of the transistor M06 outputs the initial ramp signal Isense satisfying the following relationship:

[0084] Isense=Iin*R01 / R02

[0085] It can be seen that by setting the ratio of R01 / R02 in the above formula, the amplification / reduction factor of the initial ramp signal Isense relative to the rising current of the first inductor L1 can be adjusted, thereby achieving the purpose of amplifying the rising current signal of the first inductor L1 and obtaining the amplified initial ramp signal Isense.

[0086] The slope compensation module 40 can output a slope compensation signal Islope according to the current falling slope of the first inductor L1 to compensate the initial ramp signal Isense and generate a target ramp signal Vramp. In some embodiments of the present application, the slope compensation signal Islope and the initial ramp signal Isense can both be current signals, and the target ramp signal Vramp as a voltage signal can be generated by superimposing the current signal with the input resistor. In some embodiments of the present application, the slope compensation signal Islope and the initial ramp signal Isense can also both be voltage signals, and the target ramp signal Vramp as a voltage signal can be obtained by superimposing the slope compensation signal Islope and the initial ramp signal Isense.

[0087] It can be understood that in some possible embodiments, one of the slope compensation signal Islope and the initial slope signal Isense can also be a current signal, and the other can be a voltage signal. After converting the current signal into a voltage signal, or converting the voltage signal into a current signal, the target slope signal Vramp is regenerated as a voltage signal.

[0088] The control module 50 may output a control signal Vc according to the error signal Vea and the target ramp signal Vramp, so as to control the first switch S1 in the switch impedance module 10 through the control signal Vc, and enable the switch impedance module 10 to output the second voltage VBST according to the first voltage AVDD.

[0089] For example, Figure 6 Taking the switch impedance module 10 including BOOST as an example, when the voltage of the target ramp signal Vramp is greater than the voltage of the error signal Vea, it means that the current of the first inductor L1 has completed the rising process, so the control module 50 can output a low-level control signal Vc and disconnect the first switch S1, the first inductor L1 is discharged and the current gradually decreases, the first voltage AVDD is superimposed on the induced electromotive force of the first inductor L1, and since the induced electromotive force of the first inductor L1 is in the same direction as the first voltage AVDD, a second voltage VBST with a higher voltage can be output; and during the discharge process of the first inductor L1, since the voltage of the target ramp signal Vramp is less than the voltage of the error signal Vea, when the rising edge of the clock signal arrives, the control module 50 can output a high-level control signal Vc and turn on the first switch S1, so the first voltage AVDD charges the first inductor L1, the current of the first inductor L1 gradually increases, and the first capacitor C1 discharges and outputs the second voltage VBST, until the voltage of the target ramp signal Vramp is greater than the voltage of the error signal Vea, and the above process is repeated.

[0090] As an exemplary embodiment, see Fig.11 , Fig.11Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, wherein the control module 50 includes a first comparator COMP and an RS trigger; the first input terminal of the first comparator COMP is used to access the error signal Vea, and the second input terminal of the first comparator COMP is used to access the target ramp signal Vramp; the first input terminal of the RS trigger is connected to the output terminal of the first comparator COMP, the second input terminal of the RS trigger is used to access the preset clock signal, and the output terminal of the RS trigger is connected to the control terminal of the first switch S1.

[0091] exist Fig.11 In the embodiment, when the voltage of the target ramp signal Vramp is greater than the voltage of the error signal Vea, the preset clock signal is at a low level, and the first comparator COMP outputs a high level signal, so the output end of the RS trigger can output a low level signal and control the first switch S1 to be turned off; and after the first switch S1 is turned off, the first comparator COMP outputs a low level signal, and when the rising edge of the preset clock signal arrives, the output end of the RS trigger can output a high level signal and control the first switch S1 to be turned on.

[0092] It can be understood that the above is only an exemplary embodiment of the control module 50 of the present application, and those skilled in the art can make equivalent modifications to the control module 50, such as using other logic gates, triggers and other logic circuits to replace the RS trigger and implement the functions of the control module 50.

[0093] In the embodiment of the present application, the slope compensation module 40 of the present application can output a slope compensation signal Islope whose slope changes adaptively according to the current falling slope of the first inductor L1, so that the slope of the slope compensation signal Islope changes with the current falling slope of the first inductor L1. In some implementations of the present application, the absolute value of the ratio between the slope of the slope compensation signal Islope and the current falling slope of the first inductor L1 is greater than 0.5.

[0094] For example, see Fig.12 , Fig.12A schematic diagram of related signals in the switching power supply circuit in an embodiment of the present application is shown, wherein, between time t1 and time t2, the current rising slope of the first inductor L1 is m1, and the current falling slope of the first inductor L1 is m2, and the slope compensation module 40 can output a slope compensation signal Islope with a slope of m (m>0.5|m2|, for example, m=0.75|m2|) according to the current falling slope m2 of the first inductor L1, thereby avoiding the occurrence of subharmonic oscillation between time t1 and time t2; and after time t2, the first voltage AVDD and the second voltage V At least one of BST and the inductance value of the first inductor L1 changes, so that the current rising slope of the first inductor L1 changes to m1', and the current falling slope of the first inductor L1 changes to m2'. The slope compensation module 40 can output a slope compensation signal Islope with a slope of m' (m'>0.5|m2'|, for example, m'=0.75|m2'|) according to the current falling slope m2' of the first inductor L1, thereby avoiding the occurrence of subharmonic oscillation after at least one of the first voltage AVDD, the second voltage VBST and the inductance value of the first inductor L1 changes at time t2.

[0095] It can be seen that, since the slope compensation module 40 in the embodiment of the present application can output the slope compensation signal Islope with an adaptively changing slope according to the current falling slope of the first inductor L1, when at least one of the first voltage AVDD, the second voltage VBST and the inductance value of the first inductor L1 changes, adaptive slope compensation of the switching power supply circuit can be achieved, thereby avoiding under-compensation or over-compensation caused by the traditional fixed-slope slope compensation signal Islope.

[0096] In some embodiments of the present application, see Fig.13 , Fig.13 Another schematic diagram of the switching power supply circuit in the embodiment of the present application is shown, wherein the slope compensation module 40 includes a compensation adjustment unit 41 and a compensation signal output unit 42; the compensation adjustment unit 41 is used to determine the current drop slope of the first inductor L1, and output the compensation adjustment signal Dout corresponding to the current drop slope of the first inductor L1; the compensation signal output unit 42 is used to output the ramp compensation signal Islope according to the compensation adjustment signal Dout. That is to say, the present application can use the compensation adjustment unit 41 to determine the current drop slope of the first inductor L1, and then output the compensation adjustment signal Dout corresponding to the current drop slope of the first inductor L1, so that the compensation signal output unit 42 outputs the ramp compensation signal Islope with a slope greater than 0.5 times the current drop slope of the first inductor L1 according to the compensation adjustment signal Dout.

[0097] As an exemplary embodiment of the compensation adjustment unit 41, see Fig.14 , Fig.14Another schematic diagram of the switching power supply circuit in the embodiment of the present application is shown, wherein the compensation adjustment unit 41 includes an analog-to-digital converter 411, a rising slope logic calculation unit 412, an inductance logic calculation unit 413 and a falling slope logic calculation unit 414; the analog-to-digital converter 411 is used to detect the magnitude of the current of the first inductor L1 during the current rising period of the first inductor L1, and detect the magnitude of the first voltage AVDD; the rising slope logic calculation unit 412 is used to determine the current rising slope of the first inductor L1 according to the current change during the current rising period of the first inductor L1; the inductance logic calculation unit 413 is used to determine the inductance value of the first inductor L1 according to the first voltage AVDD and the current rising slope; the falling slope logic calculation unit 414 is used to determine the current falling slope of the first inductor L1 according to the inductance value of the first inductor L1, the first voltage AVDD and the second voltage VBST.

[0098] It should be noted that the analog-to-digital converter 411 can detect the first current value of the first inductor L1 at a corresponding moment when the first switch S1 is turned on, and then detect the second current value of the first inductor L1 at a corresponding moment when the first switch S1 is turned off. Therefore, the rising slope logic calculation unit 412 can calculate the current rising slope of the first inductor L1 using the following formula:

[0099] m1=(I01-I02) / △t1

[0100] Wherein, I01 is a first current value of the first inductor L1 when the first switch S1 is turned on, I02 is a second current value of the first inductor L1 when the first switch S1 is turned off, and Δt is the turn-on time of the first switch S1.

[0101] At the same time, since during the current rising period of the first inductor L1, the first end of the first inductor L1 is connected to the first voltage AVDD, and the second end of the first inductor L1 is grounded, the current of the first inductor L1 and the first voltage AVDD satisfy the relationship formula: AVDD=L1*di / dt, at this time di / dt is the current rising slope m1 of the first inductor L1, so the inductance logic calculation unit 413 can determine the inductance value of the first inductor L1 according to the first voltage AVDD and the current rising slope m1 using the following formula:

[0102] L1=AVDD / m1

[0103] After the inductance value of the first inductor L1 is determined, during the current decrease period of the first inductor L1, since the first end of the first inductor L1 is connected to the first voltage AVDD and the second end of the first inductor L1 outputs the second voltage VBST, the current of the first inductor L1 and the first voltage AVDD and the second voltage VBST satisfy the relationship formula: AVDD-VBST=L1*di / dt. At this time, di / dt is the current decrease slope m2 of the first inductor L1. It can be known that the decrease slope logic calculation unit 414 can determine the current decrease slope of the first inductor L1 according to the inductance value of the first inductor L1, the first voltage AVDD and the second voltage VBST using the following formula:

[0104] m2=(AVDD-VBST) / L1=m1*(AVDD-VBST) / AVDD

[0105] It can be seen from the above formula that AVDD, VBST, and m1 are all known quantities obtained by measurement or calculation, so the current falling slope m2 of the first inductor L1 can be determined, and the falling slope logic calculation unit 414 outputs the compensation adjustment signal Dout according to the current falling slope m2 of the first inductor L1, thereby finally controlling the compensation signal output unit 42 to output the slope compensation signal Islope with a slope greater than 0.5 times the current falling slope m2 of the first inductor L1 according to the compensation adjustment signal Dout.

[0106] It should be noted that, in some possible embodiments, the second voltage VBST in the above formula may also be a known system setting value or obtained by measurement; in other possible embodiments, the second voltage VBST may also be determined according to a preset reference voltage Vref, for example, see Fig.15 For the embodiment in which the feedback module 20 includes a first resistor R1, a second resistor R2 and a first operational amplifier OP, the second voltage VBST can be determined by using the formula V2=Vref*(R1+R2) / R2.

[0107] As another exemplary embodiment of the compensation adjustment unit 41, see Fig.15 , Fig.15 Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, wherein the compensation adjustment unit 41 includes an analog-to-digital converter 411 and a falling slope logic calculation unit 414; the analog-to-digital converter 411 is used to detect the magnitude of the first voltage AVDD, and the falling slope logic calculation unit 414 is used to determine the current falling slope of the first inductor L1 according to the inductance value of the first inductor L1, the first voltage AVDD and the second voltage VBST.

[0108] It should be noted that, when the inductance value of the first inductor L1 is a known value, there is no need to set the rising slope logic calculation unit 412 and the inductance logic calculation unit 413. After the analog-to-digital converter 411 detects the first voltage AVDD, the falling slope logic calculation unit 414 can directly determine the current falling slope of the first inductor L1 according to the inductance value of the first inductor L1, the first voltage AVDD and the second voltage VBST formula: m2=(AVDD-VBST) / L1, so that the compensation adjustment signal Dout is output according to the current falling slope m2 of the first inductor L1, so as to control the compensation signal output unit 42 to output the slope compensation signal Islope with a slope greater than 0.5 times the current falling slope of the first inductor L1 according to the compensation adjustment signal Dout.

[0109] In some embodiments of the present application, in addition to determining the current falling slope of the first inductor L1 according to the inductance value of the first inductor L1, the first voltage AVDD and the second voltage VBST, the current falling slope of the first inductor L1 can also be determined by detecting the current change amount during the current falling period of the first inductor L1. For example, see Fig.16 , Fig.16 Another schematic diagram of the switching power supply circuit in the embodiment of the present application is shown, the compensation adjustment unit 41 includes an analog-to-digital converter 411 and a falling slope logic calculation unit 414, the analog-to-digital converter 411 is used to detect the current of the first inductor L1 at an interval of a second preset time during the current decline of the first inductor L1, and output a first digital signal and a second digital signal; the falling slope logic calculation unit 414 is used to determine the current falling slope of the first inductor L1 according to the second preset time, the first digital signal and the second digital signal.

[0110] For example, when the first switch S1 is turned off and the switch S0 and the first switch S1' are turned on, the amplifier circuit amplifies the voltage across the sampling resistor Rs and converts it through the analog-to-digital converter ADC to obtain a corresponding first digital signal (i.e., the current value of the first inductor L1 when the first switch S1 is turned off); and when the first switch S1 is turned on and the switch S0 and the first switch S1' are turned off, the amplifier circuit amplifies the voltage across the sampling resistor Rs and converts it through the analog-to-digital converter ADC to obtain a corresponding second digital signal (the current value of the first inductor L1 when the first switch S1 is turned on). Therefore, the falling slope logic calculation unit 414 can calculate the current falling slope of the first inductor L1 according to the first digital signal and the second digital signal according to the following formula:

[0111] m2=(I03-I04) / △t2

[0112] Wherein, I03 is the current value of the first inductor L1 when the first switch S1 is turned off, I04 is the current value of the first inductor L1 when the first switch S1 is turned on again, and Δt2 is the off time of the first switch S1.

[0113] After determining the current falling slope of the first inductor L1, the falling slope detection subunit 410 can output the compensation adjustment signal Dout according to the current falling slope m2 of the first inductor L1, so as to control the compensation signal output unit 42 to output the ramp compensation signal Islope having a slope greater than 0.5 times the current falling slope of the first inductor L1 according to the compensation adjustment signal Dout.

[0114] In some embodiments of the present application, see Fig.17 , Fig.17 A schematic diagram of the compensation signal output unit 42 in an embodiment of the present application is shown, wherein the compensation signal output unit 42 includes a first current source IS1, a second current source IS2, a first transistor M1, a second transistor M2, a second capacitor C2, a second switch S2, a third resistor R3, a fourth resistor R4, a third transistor M3, a fourth transistor M4 and a fifth transistor M5; the input end of the first current source IS1 is connected to the power supply end, and the output end of the first current source IS1 is connected to the second end of the first transistor M1; the control end of the first transistor M1 is connected to the second end of the first transistor M1, the first end of the first transistor M1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the ground end; the input end of the second current source IS2 is connected to the power supply end, and the output end of the second current source IS2 is connected to the second end of the second transistor M2; the control end of the second transistor M2 is connected to the first transistor M1 The first end of the second transistor M2 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is connected to the ground end; the first end of the second switch S2 is connected to the second end of the fourth resistor R4, and the second end of the second switch S2 is connected to the ground end; the first end of the third transistor M3 is connected to the power supply end, and the control end of the third transistor M3 is connected to the second end of the third transistor M3; the second end of the fifth transistor M5 is connected to the second end of the third transistor M3, the control end of the fifth transistor M5 is connected to the second end of the second transistor M2, and the first end of the fifth transistor M5 is connected to the first end of the first transistor M1; the first end of the fourth transistor M4 is connected to the power supply end, the control end of the fourth transistor M4 is connected to the control end of the third transistor M3, and the second end of the fourth transistor M4 is used to output the ramp compensation signal Islope.

[0115] It should be noted that when the second switch S2 is disconnected, the second current source IS2 charges the second capacitor C2 through the second transistor M2, and the source voltage of the second transistor M2 gradually increases, so the current flowing through the branch where the second transistor M2 is located gradually decreases, the control terminal voltage of the fifth transistor M5 (that is, the drain voltage of the second transistor) gradually increases, and the current flowing through the branch where the third transistor M3 and the fifth transistor M5 are located gradually increases. Since the third transistor M3 and the fourth transistor M4 are connected in common source and common gate and serve as current mirrors, the fourth transistor M4 can output the ramp compensation signal Islope with a gradually increasing current; and when the second switch S2 is closed, the first end of the second transistor M2 is grounded through the fourth resistor R4, the source voltage of the second transistor M2 is reduced and turned on, and since the control end of the fifth transistor M5 is connected to the second end of the second transistor M2, the control end voltage of the fifth transistor M5 will be reduced and turned off after the second transistor M2 is turned on, so the current flowing through the branch where the third transistor M3 and the fifth transistor M5 are located becomes 0. During the process of the second switch S2 being alternately closed and opened, a periodically changing slope compensation signal Islope is outputted; Fig.17 In the embodiment, when the slope compensation signal Islope and the initial slope signal Isense are both input into the fifth resistor R5, a target slope signal Vramp as a voltage signal can be outputted at one end of the fifth resistor R5.

[0116] In some embodiments of the present application, the compensation adjustment signal Dout can control the mirror ratio between the third transistor M3 and the fourth transistor M4. Fig.17 The compensation adjustment signal Dout can control the parallel quantity of the fourth transistor M4, thereby changing the mirror ratio of the third transistor M3 and the fourth transistor M4, and finally changing the slope of the ramp compensation signal Islope.

[0117] It can be understood that, in some possible embodiments, the compensation adjustment signal Dout can also control the mirror ratio between the first transistor M1 and the second transistor M2 to change the slope of the ramp compensation signal Islope; or, in other possible embodiments, the compensation adjustment signal Dout can also control the magnitude of the output current of the first current source IS1 to change the slope of the ramp compensation signal Islope.

[0118] In order to better implement the switching power supply circuit in the embodiment of the present application, on the basis of the switching power supply circuit, the present application also provides a power supply system, the power supply system includes the switching power supply circuit as described in any of the above embodiments. Since the power supply system of the present application has the switching power supply circuit described in the above embodiments, it has all the beneficial effects of the switching power supply circuit in the above embodiments, which will not be repeated here.

[0119] The embodiment of the present application also provides an electronic device, which includes a device body and a power supply system as described above, which is arranged in the device body. The electronic device can be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply, a wireless charger, a fast charger, a car charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a stylus, a true wireless headset, a car central control screen, a car, a smart wearable device, a mobile terminal, and a smart home device. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal). Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart sweepers, and smart lights.

[0120] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A switching power supply circuit, characterized in that: include: A switch impedance module, the switch impedance module comprising a first inductor and at least one first switch, the switch impedance module being used to access a first voltage and output a second voltage under the control of a control signal on the first switch; a feedback module, the feedback module being configured to output an error signal according to the second voltage and a preset reference voltage; an inductor current detection module, the inductor current detection module being used to output an initial ramp signal according to a rising current of the first inductor; A slope compensation module, the slope compensation module is used to output a slope compensation signal according to the current falling slope of the first inductor to compensate the initial ramp signal and generate a target ramp signal; A control module, the control module is used to output the control signal according to the error signal and the target ramp signal; The slope of the ramp compensation signal changes with the current decreasing slope of the first inductor.

2. The switching power supply circuit according to claim 1, characterized in that: An absolute value of a ratio of a slope of the ramp compensation signal to a current falling slope of the first inductor is greater than 0.

5.

3. The switching power supply circuit according to claim 1, characterized in that: The slope compensation module includes a compensation adjustment unit and a compensation signal output unit; The compensation adjustment unit is used to determine the current falling slope of the first inductor and output a compensation adjustment signal corresponding to the current falling slope of the first inductor; The compensation signal output unit is used to output the ramp compensation signal according to the compensation adjustment signal.

4. The switching power supply circuit according to claim 3, characterized in that: The compensation adjustment unit includes an analog-to-digital converter, a rising slope logic calculation unit, an inductance logic calculation unit, and a falling slope logic calculation unit; The analog-to-digital converter is used to detect the magnitude of the current of the first inductor and the magnitude of the first voltage during the period when the current of the first inductor rises; The rising slope logic calculation unit is used to determine the current rising slope of the first inductor according to the current change amount during the rising period of the first inductor current; The inductance logic calculation unit is used to determine the inductance value of the first inductor according to the first voltage and the current rising slope; The falling slope logic calculation unit is used to determine the current falling slope of the first inductor according to the inductance value of the first inductor, the first voltage and the second voltage.

5. The switching power supply circuit according to claim 3, characterized in that: The compensation adjustment unit includes an analog-to-digital converter and a falling slope logic calculation unit; The analog-to-digital converter is used to detect the magnitude of the first voltage; The falling slope logic calculation unit is used to determine the current falling slope of the first inductor according to the inductance value of the first inductor, the first voltage and the second voltage.

6. The switching power supply circuit according to claim 3, characterized in that: The compensation adjustment unit includes an analog-to-digital converter and a falling slope logic calculation unit; The analog-to-digital converter is used to detect the current of the first inductor at intervals of a second preset time during a period when the current of the first inductor decreases, and output a first digital signal and a second digital signal; The falling slope logic calculation unit is used to determine the current falling slope of the first inductor according to the second preset time, the first digital signal and the second digital signal.

7. The switching power supply circuit according to claim 3, characterized in that: The compensation signal output unit includes a first current source, a second current source, a first transistor, a second transistor, a second capacitor, a second switch, a third resistor, a fourth resistor, a third transistor, a fourth transistor and a fifth transistor; The input end of the first current source is connected to the power supply end, and the output end of the first current source is connected to the second end of the first transistor; The control end of the first transistor is connected to the second end of the first transistor, the first end of the first transistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the ground end; The input end of the second current source is connected to the power supply end, and the output end of the second current source is connected to the second end of the second transistor; The control end of the second transistor is connected to the control end of the first transistor, the first end of the second transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the ground end; The first end of the second switch is connected to the second end of the fourth resistor, and the second end of the second switch is connected to the ground end; The first end of the third transistor is connected to the power supply end, and the control end of the third transistor is connected to the second end of the third transistor; The second end of the fifth transistor is connected to the second end of the third transistor, the control end of the fifth transistor is connected to the second end of the second transistor, and the first end of the fifth transistor is connected to the first end of the first transistor; The first end of the fourth transistor is connected to the power supply end, the control end of the fourth transistor is connected to the control end of the third transistor, and the second end of the fourth transistor is used to output the ramp compensation signal.

8. The switching power supply circuit according to claim 7, characterized in that: The compensation adjustment signal is used to control the mirror ratio between the first transistor and the second transistor; and / or The compensation adjustment signal is used to control the mirror ratio between the third transistor and the fourth transistor.

9. The switching power supply circuit according to claim 1, characterized in that: The feedback module includes a first resistor, a second resistor and a first operational amplifier; The first end of the first resistor is used to access the second voltage, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the ground end; The first input terminal of the first operational amplifier is connected to a first node between the first resistor and the second resistor, the second input terminal of the first operational amplifier is used to access the preset reference voltage, and the output terminal of the first operational amplifier is used to output the error signal.

10. The switching power supply circuit according to claim 1, characterized in that: The control module includes a first comparator and an RS trigger; The first input terminal of the first comparator is used to access the error signal, and the second input terminal of the first comparator is used to access the target ramp signal; The first input end of the RS trigger is connected to the output end of the first comparator, the second input end of the RS trigger is used to access a preset clock signal, and the output end of the RS trigger is connected to the control end of the first switch.

11. A power supply system, characterized in that: The invention comprises a switching power supply circuit as claimed in any one of claims 1 to 10.

12. An electronic device, characterized in that: Comprising the power supply system as claimed in claim 11.

Images