Switching power supply circuit, power supply system, and electronic device

Abstract

A switching power supply circuit, a power supply system, and an electronic device. The switching power supply circuit comprises 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); the switching impedance module (10) comprises a first inductor (L1), a first capacitor (C1), and at least one first switch (S1); the feedback module (20) is configured to output an error signal (Vea) on the basis of a second voltage (VBST) and a preset reference voltage (Vref); the inductor current detection module (30) is configured to output an initial ramp signal (Isense) on the basis of a rising current of the first inductor; the slope compensation module (40) is configured to output a slope compensation signal (Islope) on the basis of a current falling slope of the first inductor; and the control module (50) is configured to output a control signal (Vc) on the basis of the error signal (Vea) and a target ramp signal (Vramp). The slope compensation module (40) of the present application can output the slope compensation signal (Islope) having an adaptively changing slope, and for different input voltages, output voltages or inductors, the adaptively changing slope compensation signal (Islope) can avoid the occurrence of undercompensation or overcompensation.

Description

Switching power supply circuits, power supply systems, and electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 202510005016.X, filed on January 2, 2025, entitled "Switching Power Supply Circuit, Power Supply System and Electronic Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of integrated circuit technology, specifically to a switching power supply circuit, a power supply system, and electronic equipment. Background Technology

[0003] A DC-to-DC converter is a switching power supply circuit that converts DC power into DC power of different voltages, thus meeting the power supply needs of circuit modules with different supply voltages. Currently, among various DC-to-DC converters, peak current control mode DC-to-DC converters are the most widely used in practice due to their advantages over voltage control mode DC-to-DC converters, such as faster response speed and the elimination of the need for a lead compensation network.

[0004] In related technologies, DC-DC converters with peak current control mode mainly include a switching circuit, a voltage feedback loop, and a current feedback loop, controlling the switching circuit through dual voltage and current feedback. In the current feedback loop, a slope compensation circuit is typically used to prevent subharmonic oscillations when the feedback control signal duty cycle exceeds 50%. However, traditional slope compensation circuits use a fixed slope for the compensation signal. When the input voltage, output voltage, or inductance changes, this fixed slope can lead to undercompensation or overcompensation in the DC-DC converter, resulting in subharmonic oscillations or a shift to voltage-mode control. This negates the advantages of current-mode control and, in severe cases, affects the efficiency or dynamic performance of the DC-DC converter. Technical solutions

[0005] In view of the above problems, embodiments of this application provide a switching power supply circuit, a power supply system, and an electronic device to solve the above technical problems.

[0006] In a first aspect, embodiments of this application provide a switching power supply circuit, including:

[0007] A switching impedance module includes a first inductor, a first capacitor, and at least one first switch. The switching impedance module is used to receive a first voltage and output a second voltage under the control of the first switch by a control signal.

[0008] The feedback module is used to output an error signal based on the second voltage and the preset reference voltage.

[0009] The inductor current detection module is used to output an initial ramp signal based on the rising current of the first inductor.

[0010] The slope compensation module is used to output a slope compensation signal based on the current drop slope of the first inductor to compensate the initial slope signal and generate the target slope signal.

[0011] The control module is used to output control signals based on the error signal and the target slope signal.

[0012] The slope of the ramp compensation signal follows the slope of the current decrease in the first inductor.

[0013] Secondly, embodiments of this application also provide a power supply system, including the aforementioned switching power supply circuit.

[0014] Thirdly, embodiments of this application also provide an electronic device, including the power supply system or switching power supply circuit described above.

[0015] These or other aspects of this application will become more apparent from the description of the following embodiments. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 shows a schematic diagram of a DC-DC converter in the related technology.

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

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

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

[0021] Figure 5 shows a schematic diagram of a switching power supply circuit in an embodiment of this application.

[0022] Figure 6 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0023] Figure 7 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0024] Figure 8 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0025] Figure 9 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0026] Figure 10 shows a schematic diagram of an inductor current detection module in an embodiment of this application.

[0027] Figure 11 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0028] Figure 12 shows a schematic diagram of relevant signals in the switching power supply circuit in an embodiment of this application.

[0029] Figure 13 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0030] Figure 14 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0031] Figure 15 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0032] Figure 16 shows another schematic diagram of the switching power supply circuit in an embodiment of this application.

[0033] Figure 17 shows a schematic diagram of a compensation signal output unit in an embodiment of this application.

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

[0035] First inductor L1, first capacitor C1, 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] First current source IS1, first transistor M1, second transistor M2, second capacitor C2, second switch S2, third resistor R3, third transistor M3, fourth transistor M4, first resistor R1, second resistor R2, first operational amplifier OP, first comparator COMP.

[0038] Implementation methods of this application

[0039] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0040] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0041] In the embodiments of this application, it should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0042] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] In the description of the embodiments of this application, the words "example" or "for example" are used to indicate exemplification, illustration, or description. Any embodiment or design described as "example" or "for example" in the embodiments of this application is not to be construed as being more preferred or having more advantages than another embodiment or design. The use of the words "example" or "for example" is intended to present relative concepts in a clear manner.

[0044] Furthermore, in the embodiments of this application, "multiple" refers to two or more. Therefore, in the embodiments of this application, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, such as one, two, or more. For example, including at least one means including one, two, or more, and is not limited to which ones are included. For example, including at least one of A, B, and C, then it could include A, B, C, A and B, A and C, B and C, or A and B and C.

[0045] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. 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 a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0046] In the embodiments of this application, the first terminal / first end of each transistor is one of the source and the drain, and the second terminal / second end of each transistor is the other of the source and the drain. Since the source and drain of a transistor can be structurally symmetrical, they can be structurally indistinguishable. That is, the first terminal / first end and the second terminal / second end of the transistor in the embodiments of this application can be structurally indistinguishable. For example, when the transistor is a P-type transistor, the first terminal / first end is the source, and the second terminal / second end is the drain; for example, when the transistor is an N-type transistor, the first terminal / first end is the drain, and the second terminal / second end is the source.

[0047] In the circuit structure provided by the embodiments of this application, nodes such as the first node and the second node do not represent actual existing components, but rather represent the junction points of related couplings in the circuit diagram. In other words, these nodes are equivalent to the junction points of related couplings in the circuit diagram.

[0048] Currently, peak current control mode DC-DC converters are the most widely used switching power supplies. Referring to Figure 1, Figure 1 shows a schematic diagram of a DC-DC converter in related technologies. The DC-DC converter includes a BOOST boost circuit and a feedback control circuit that controls the BOOST boost circuit. The BOOST boost circuit consists of an inductor L0, a diode D0, a voltage regulator capacitor C0, and a transistor MN1. The feedback control circuit consists 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 flip-flop. This allows the feedback control circuit to control the transistor MN1 in the BOOST boost circuit, so that the BOOST boost circuit outputs a boosted output voltage Vout based on the input voltage VDD.

[0049] 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. Therefore, the voltage feedback loop can output an error signal Verror to the non-inverting input terminal of the comparator COMP. The current detection circuit can output an amplified current signal I1 during the rising period of the inductor L0 current. 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, and the ramp signal Vra is input to the inverting input terminal of the comparator, finally forming a dual-loop feedback control circuit of the voltage loop and the current loop, and outputting a feedback control signal PWM through the comparator COMP and the RS flip-flop connected to the clock signal LCK.

[0050] For a DC-DC converter in peak current control mode, subharmonic oscillation is a common phenomenon in a switching power supply using 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 the subharmonic oscillation phenomenon occurs, if there is a small fluctuation in the inductor current, the fluctuation of this circuit will increase in the next cycle.

[0051] For example, referring to Figure 2, Figure 2 shows a schematic diagram of 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%. In Figure 2, the solid line is the ideal current of the inductor L0, the dashed line is the actual current of the inductor L0, and ΔI0 is the error current caused by the influence of the external environment on the current of the inductor L0 in the previous cycle. After one cycle, the error current ΔI1 of the inductor current satisfies the following relationship: ΔI1 = -ΔI0 * k2 / k1

[0052] Among them, k1 is the rising slope of the inductor current, and k2 is the falling slope of the inductor current.

[0053] Since the duty cycle of the feedback control signal PWM 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 the subharmonic oscillation phenomenon will not be caused.

[0054] When the duty cycle of the feedback control signal PWM is greater than 50%, if the ramp compensation circuit is not used for ramp compensation, referring to Figure 3, Figure 3 shows a schematic diagram of 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%. After one cycle, the error current ΔI1 of the inductor current satisfies the following relationship: ΔI1 = -ΔI0 * k2 / k1

[0055] Since the PWM duty cycle of the feedback control signal is greater than 50%, we know that k2>k1. Therefore, ΔI1 is greater than ΔI0. After several cycles, the error current diverges, which eventually leads to subharmonic oscillation.

[0056] To avoid subharmonic oscillations when the feedback control signal duty cycle is greater than 50%, DC-DC converters typically incorporate a slope compensation circuit, as shown in Figure 1. This circuit outputs a compensation current signal I2. The amplified current signal I1 is then superimposed with the compensation current signal I2 and passed through resistor R03 to generate a slope signal Vra. If the voltage corresponding to the compensation current signal I2 is equivalently represented on the error signal Verror, the changes in the ideal current and the actual current of inductor L0 are shown in Figure 4. After slope 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. Therefore, after one cycle, the error current ΔI1 of the inductor current satisfies the following relationship: ΔI1=-ΔI0*(k2-k) / (k1+k)

[0057] 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. Therefore, ΔI1 is less than ΔI0. After several cycles, the error current converges, thus solving the subharmonic oscillation phenomenon caused by the PWM duty cycle of the feedback control signal being greater than 50%.

[0058] However, traditional slope compensation circuits use a fixed slope of the slope compensation signal (i.e., the slope k of the sawtooth wave compensation signal is a fixed value). When any of the input voltage, output voltage, or inductance changes, the fixed slope compensation slope may cause the DC-DC converter to experience undercompensation or overcompensation. This can lead to subharmonic oscillations or a change to voltage-mode control, which would negate the advantages of current-mode control and, in severe cases, affect the efficiency or dynamic performance of the DC-DC converter.

[0059] Therefore, this application provides a switching power supply circuit, a power supply system, and an electronic device, which are described in detail below.

[0060] First, referring to Figure 5, Figure 5 shows a schematic diagram of a switching power supply circuit in an embodiment of this application, 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.

[0061] Specifically, the switching impedance module 10 is used to receive a first voltage AVDD and outputs a second voltage VBST under the control of the first switch S1 by the control signal Vc. The second voltage VBST can be greater than the first voltage AVDD, or the second voltage VBST can be less than the first voltage AVDD. For example, the switching impedance module 10 may include a BOOST boost circuit so that the switching impedance module 10 outputs a higher second voltage VBST based on the first voltage AVDD; or, for example, the switching impedance module 10 may include a BUCK buck circuit so that the switching impedance module 10 outputs a lower second voltage VBST based on the first voltage AVDD.

[0062] It should be noted that the switching impedance module 10 includes a first inductor L1, a first capacitor C1, and at least one first switch S1. The connection method of the first inductor L1, the first capacitor C1, and at least one first switch S1 is different in the BOOST boost circuit and the BUCK buck circuit.

[0063] For example, taking the BOOST boost circuit as an example, referring to Figure 6, Figure 6 shows another schematic diagram of the switching power supply circuit in the embodiment of this application, 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 terminal, the control terminal 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 terminal, and the first end of the first capacitor C1 outputs the second voltage VBST.

[0064] 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 the 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 discharges and the current gradually decreases, the first diode D1 is in the on state, and the first voltage AVDD is superimposed with the induced electromotive force of the first inductor L1. Since the induced electromotive force of the first inductor L1 is in the same direction as the first voltage AVDD, a higher second voltage VBST can be output.

[0065] For example, taking the BUCK step-down circuit as an example, referring to Figure 7, Figure 7 shows another schematic diagram of the switching power supply circuit in the embodiment of this application. The first terminal of the first switch S1 is connected to the first voltage AVDD, the second terminal of the first switch S1 is connected to the first terminal of the first inductor L1, the second terminal of the first inductor L1 is connected to the first terminal of the first capacitor C1, the second terminal of the first capacitor C1 is connected to the ground terminal, the first terminal of the first capacitor C1 outputs the second voltage VBST, the first terminal of the first diode D1 is connected to the first terminal of the first inductor L1, and the second terminal of the first diode D1 is connected to the ground terminal.

[0066] When the control signal Vc controls the first switch S1 to open, the first inductor L1 discharges and its current gradually decreases, the first diode D1 is in the conducting state, and the first capacitor C1 discharges to output the second voltage VBST. When the control signal Vc controls the first switch S1 to open, the first inductor L1 charges and its current gradually increases, the first diode D1 is in the cutoff state, and the first voltage AVDD is superimposed with 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 lower second voltage VBST can be output.

[0067] It is understood that Figures 6 and 7 above are only exemplary embodiments of the switching impedance module 10 of this application. Those skilled in the art can make equivalent modifications to the switching impedance module under the guidance of this application. For example, the switching impedance module 10 may also include a Buck-Boost converter circuit. For another example, referring to Figure 8, Figure 8 shows another schematic diagram of the switching power supply circuit in the embodiment of this application. In the above embodiment, the first diode D1 can also be replaced by a switch S1'. It is only necessary to invert the control signal Vc and input it to the control terminal of the switch S1'.

[0068] Feedback module 20 is used to output an error signal Vea based on the second voltage VBST and a preset reference voltage Vref to form a voltage feedback loop in the peak current control mode. In some embodiments of this application, such as for embodiments where the switching impedance module 10 includes a BUCK step-down circuit, feedback module 20 may employ an operational amplifier to output the error signal Vea based on the second voltage VBST and the preset reference voltage Vref. In some embodiments of this application, such as for embodiments where the switching impedance module 10 includes a BOOST step-up circuit, feedback module 20 may employ a resistor divider circuit and an operational amplifier to output the error signal Vea based on the second voltage VBST and the preset reference voltage Vref.

[0069] For example, taking the switching impedance module 10 including a BOOST boost circuit as an example, referring to Figure 9, Figure 9 shows another schematic diagram of the switching power supply circuit in an embodiment of this application, 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 connect to 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 terminal; the first input terminal 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 terminal of the first operational amplifier OP is used to connect to the preset reference voltage Vref, and the output terminal of the first operational amplifier OP is used to output the error signal Vea.

[0070] 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 adjust the magnitude of the second voltage VBST. After the feedback loop stabilizes, the voltages at the first and second input terminals of the first operational amplifier OP are equal. Therefore, the second voltage VBST and the preset reference voltage Vref satisfy the following relationship: VBST=Vref*(R1+R2) / R2, thereby realizing the voltage negative feedback regulation of the switching power supply circuit.

[0071] The inductor current detection module 30 is used to output an initial ramp signal Isense based on 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 this application, the inductor current detection module 30 can mirror the rising current of the first inductor L1 to 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 this 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, where N>1.

[0072] As an example, referring to FIG10, FIG10 shows a schematic diagram of an inductor current detection module 30 in an embodiment of the present application. The inductor current detection module 30 includes a current source IS01, a current source IS02, transistors M01 to M06, and resistors R01 to R03. The second terminal of transistor M01 is connected to one end of a first inductor L1 to receive the rising current Iin of the first inductor L1. The control terminal of transistor M01 is connected to a control signal Vc. The first terminal of transistor M01 is connected to the first terminal of resistor R01, and the second terminal of resistor R01 is connected to ground. The input terminal of current source IS01 is connected to the power supply terminal VDD, and the output terminal of current source IS01 is connected to the second terminal of transistor M02. The control terminal of transistor M02 is connected to the control terminal of transistor M03. The first terminal of transistor M02 is connected to the first terminal of resistor R02, and the second terminal of resistor R02 is connected to the second terminal of resistor R03. The first terminal of transistor M05 is connected to the power supply terminal VDD. The output terminal of current source IS02 is connected to the second terminal of transistor M03. The second terminal of transistor M03 is connected to the control terminal of transistor M03. The first terminal of transistor M03 is connected to the first terminal of resistor R03. The second terminal of resistor R03 is connected to the ground terminal. The first terminal of transistor M05 is connected to the power supply terminal VDD. The control terminal of transistor M05 is connected to the second terminal of transistor M05. The second terminal of transistor M05 is connected to the first terminal of transistor M04. The control terminal of transistor M04 is connected to the second terminal of transistor M02. The first terminal of transistor M04 is connected to the first terminal of resistor R03. The first terminal of transistor M06 is connected to the power supply terminal VDD. The control terminal of transistor M06 is connected to the control terminal of transistor M05. The second terminal of transistor M06 is used to output the initial ramp signal Isense.

[0073] Specifically, in Figure 10, the source voltages of transistor M02 and M03 can be calculated using the following formulas: VS2 = I01 * R02 + (Iin + I01) * R01 VS3 = I02 * R03 + I_M04 * R03

[0074] Where VS2 is the source voltage of transistor M02, VS3 is the source voltage of transistor M03, Iin is the inductor current, I01 is the current output by current source IS01, I02 is the current output by current source IS02, and I_M04 is the output current of transistor M04.

[0075] Since transistors M02 and M03 act as current mirrors of each other with a 1:1 mirror ratio, VS2 = VS3. Furthermore, since I01 is much smaller than Iin and R01 is much smaller than R02, the I01*R01 term can be ignored. Based on VS2 = VS3, we can derive the following formula: I01*R02 + Iin*R01 = I02*R03 + I_M04*R03

[0076] When the output currents from current sources IS01 and IS02 are equal, and the resistances of resistors R02 and R03 are equal, the current flowing through transistor M04 satisfies the following relationship: I_M04=Iin*R01 / R02

[0077] Meanwhile, since the current mirror flowing through transistor M05 is equal to the current flowing through transistor M04, and transistors M05 and M06 are current mirrors of each other, assuming the mirror ratio between transistors M05 and M06 is 1, the initial ramp signal Isense output from the second terminal of transistor M06 satisfies the following relationship: Isense = Iin * R01 / R02

[0078] It can be seen that by setting the ratio of R01 / R02 in the above formula, the amplification factor / 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.

[0079] The slope compensation module 40 can output a slope compensation signal Islope based on the current drop slope of the first inductor L1 to compensate for the initial slope signal Isense and generate a target slope signal Vramp. In some embodiments of this application, both the slope compensation signal Islope and the initial slope signal Isense can be current signals. The target slope signal Vramp, which is a voltage signal, is generated by superimposing the current signals onto the input resistor. In some embodiments of this application, both the slope compensation signal Islope and the initial slope signal Isense can also be voltage signals. The target slope signal Vramp, which is a voltage signal, is obtained by superimposing the slope compensation signal Islope and the initial slope signal Isense.

[0080] Understandably, in some possible embodiments, either the slope compensation signal Islope or the initial slope signal Isense can be a current signal and the other a voltage signal. After converting the current signal into a voltage signal or the voltage signal into a current signal, the target slope signal Vramp is regenerated into a voltage signal.

[0081] The control module 50 can output a control signal Vc based on the error signal Vea and the target ramp signal Vramp, so as to control the first switch S1 in the switching impedance module 10 through the control signal Vc, and make the switching impedance module 10 output a second voltage VBST based on the first voltage AVDD.

[0082] For example, taking the BOOST boosting module 10 in Figure 6 as an example, when the voltage of the target ramp signal Vramp is greater than the voltage of the error signal Vea, it indicates that the current of the first inductor L1 has completed the rising process. Therefore, the control module 50 can output a low-level control signal Vc and cause the first switch S1 to open, the first inductor L1 discharges and the current gradually decreases, 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 same direction as the first voltage AVDD, a higher second voltage VBST can be output. 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 cause the first switch S1 to turn on. Therefore, the first voltage AVDD charges the first inductor L1, the current of the first inductor L1 gradually increases, 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.

[0083] As an exemplary embodiment, referring to FIG11, FIG11 shows another schematic diagram of the switching power supply circuit in an embodiment of the present application, wherein the control module 50 includes a first comparator COMP and an RS flip-flop; the first input terminal of the first comparator COMP is used to receive an error signal Vea, and the second input terminal of the first comparator COMP is used to receive a target ramp signal Vramp; the first input terminal of the RS flip-flop is connected to the output terminal of the first comparator COMP, the second input terminal of the RS flip-flop is used to receive a preset clock signal, and the output terminal of the RS flip-flop is connected to the control terminal of the first switch S1.

[0084] In Figure 11, when the voltage of the target ramp signal Vramp is greater than the voltage of the error signal Vea, the preset clock signal is low, the first comparator COMP outputs a high-level signal, so the output of the RS flip-flop can output a low-level signal and control the first switch S1 to open; after the first switch S1 is open, the first comparator COMP outputs a low-level signal, and when the rising edge of the preset clock signal arrives, the output of the RS flip-flop can output a high-level signal and control the first switch S1 to turn on.

[0085] It is understood that the above is only an exemplary embodiment of the control module 50 of this application. Those skilled in the art can make equivalent modifications to the control module 50, such as using other logic gates, flip-flops or other logic circuits to replace the RS flip-flop and implement the function of the control module 50.

[0086] In this embodiment, the slope compensation module 40 can output a slope-adaptively changing slope compensation signal Islope based on the current-decreasing slope of the first inductor L1, so that the slope of the slope compensation signal Islope follows the current-decreasing slope of the first inductor L1. In some embodiments of this application, the absolute value of the ratio between the slope of the slope compensation signal Islope and the current-decreasing slope of the first inductor L1 is greater than 0.5.

[0087] For example, referring to Figure 12, which shows a schematic diagram of relevant signals in a switching power supply circuit according to an embodiment of this application, the current rising slope of the first inductor L1 is m1 and the current falling slope of the first inductor L1 is m2 between time t1 and time t2. 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|) based on the current falling slope m2 of the first inductor L1, thereby avoiding subharmonic oscillations between time t1 and time t2; while after time t2, the first voltage AVDD If at least one of the second voltage VBST and the inductance value of the first inductor L1 changes, the rising slope of the current of the first inductor L1 changes to m1' and the falling slope of the current 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 falling slope of the current of the first inductor L1 m2', thereby avoiding the occurrence of subharmonic oscillation after the first voltage AVDD, the second voltage VBST and the inductance value of the first inductor L1 change at time t2.

[0088] As can be seen, since the slope compensation module 40 in this embodiment can output a slope adaptively changing slope compensation signal Islope according to the current drop 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 realized, thereby avoiding the undercompensation or overcompensation phenomenon caused by the traditional fixed slope slope compensation signal Islope.

[0089] In some embodiments of this application, referring to FIG13, FIG13 shows another schematic diagram of a switching power supply circuit in an embodiment of this application, 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 a 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 a ramp compensation signal Islope according to the compensation adjustment signal Dout. That is, this 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 a 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.

[0090] As an exemplary embodiment of the compensation adjustment unit 41, referring to FIG14, FIG14 shows another schematic diagram of the switching power supply circuit in an embodiment of the present application, 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 rising period of the current of the first inductor L1, and to detect the magnitude of the first voltage AVDD; the rising slope logic calculation unit 412 is used to determine the rising slope of the current of the first inductor L1 based on the amount of current change during the rising period of the current of the first inductor L1; the inductance logic calculation unit 413 is used to determine the inductance value of the first inductor L1 based on the first voltage AVDD and the rising slope of the current; the falling slope logic calculation unit 414 is used to determine the falling slope of the current of the first inductor L1 based on the inductance value of the first inductor L1, the first voltage AVDD, and the second voltage VBST.

[0091] It should be noted that the analog-to-digital converter 411 can detect the first current value of the first inductor L1 at the corresponding moment when the first switch S1 is turned on, and then detect the second current value of the first inductor L1 at the 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: m1=(I01-I02) / △t1

[0092] Wherein, I01 is the first current value of the first inductor L1 when the first switch S1 is turned on, I02 is the second current value of the first inductor L1 when the first switch S1 is turned off, and Δt is the on-time of the first switch S1.

[0093] Meanwhile, since the first terminal of the first inductor L1 is connected to the first voltage AVDD and the second terminal of the first inductor L1 is grounded during the current rise of the first inductor L1, the current of the first inductor L1 and the first voltage AVDD satisfy the following relationship formula: AVDD = L1 * di / dt. At this time, di / dt is the current rise slope m1 of the first inductor L1. Therefore, 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 rise slope m1 using the following formula: L1 = AVDD / m1

[0094] After determining the inductance value of the first inductor L1, during the current decrease of the first inductor L1, since the first voltage AVDD is connected to the first terminal of the first inductor L1 and the second voltage VBST is output from the second terminal of the first inductor L1, the current of the first inductor L1 satisfies the relationship between the first voltage AVDD and the second voltage VBST as follows: AVDD - VBST = L1 * di / dt. At this time, di / dt is the current decrease slope m2 of the first inductor L1. It can be seen that the current 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: m2 = (AVDD - VBST) / L1 = m1 * (AVDD - VBST) / AVDD

[0095] As can be seen from the above formula, AVDD, VBST, and m1 are all known quantities obtained by measurement or calculation. Therefore, the current drop slope m2 of the first inductor L1 can be determined, and the drop slope logic calculation unit 414 can output a compensation adjustment signal Dout based on the current drop slope m2 of the first inductor L1. This ultimately controls the compensation signal output unit 42 to output a slope compensation signal Islope with a slope greater than 0.5 times the current drop slope m2 of the first inductor L1 based on the compensation adjustment signal Dout.

[0096] It should be noted that in some possible embodiments, the second voltage VBST in the above formula can also be a known system set value or obtained by measurement; in other possible embodiments, the magnitude of the second voltage VBST can also be determined according to the preset reference voltage Vref. For example, referring to Figure 15, for an embodiment of the feedback module 20 including a first resistor R1, a second resistor R2 and a first operational amplifier OP, the second voltage VBST can be determined using the formula V2=Vref*(R1+R2) / R2.

[0097] As another exemplary embodiment of the compensation adjustment unit 41, referring to FIG15, FIG15 shows another schematic diagram of the switching power supply circuit in the embodiment of the present application, wherein the compensation adjustment unit 41 includes an analog-to-digital converter 411 and a descent slope logic calculation unit 414; the analog-to-digital converter 411 is used to detect the magnitude of the first voltage AVDD, and the descent slope logic calculation unit 414 is used to determine the current descent slope of the first inductor L1 based on the inductance value of the first inductor L1, the first voltage AVDD and the second voltage VBST.

[0098] It should be noted that when the inductance value of the first inductor L1 is known, there is no need to set up the rising slope logic calculation unit 412 and the inductance logic calculation unit 413. After the analog-to-digital converter 411 detects the magnitude of the first voltage AVDD, the falling slope logic calculation unit 414 can directly determine the current falling slope of the first inductor L1 based on the inductance value of the first inductor L1, the first voltage AVDD, and the second voltage VBST formula: m2=(AVDD-VBST) / L1. This allows the compensation adjustment signal Dout to be output based on the current falling slope m2 of the first inductor L1, so that the compensation signal output unit 42 can be controlled to output a slope compensation signal Islope with a slope greater than 0.5 times the current falling slope of the first inductor L1 based on the compensation adjustment signal Dout.

[0099] In some embodiments of this application, besides determining the current drop slope of the first inductor L1 based on the inductance value of the first inductor L1, the first voltage AVDD, and the second voltage VBST, the current drop slope of the first inductor L1 can also be determined by detecting the amount of current change during the current drop of the first inductor L1. For example, referring to FIG16, FIG16 shows another schematic diagram of a switching power supply circuit in an embodiment of this application. The compensation adjustment unit 41 includes an analog-to-digital converter 411 and a drop slope logic calculation unit 414. The analog-to-digital converter 411 is used to detect the current of the first inductor L1 at second preset time intervals during the current drop of the first inductor L1, and output a first digital signal and a second digital signal; the drop slope logic calculation unit 414 is used to determine the current drop slope of the first inductor L1 based on the second preset time, the first digital signal, and the second digital signal.

[0100] For example, when the first switch S1 is open and switches S0 and S1' are closed, the amplifier circuit amplifies the voltage across the sampling resistor Rs and converts it through an analog-to-digital converter (ADC) to obtain the corresponding first digital signal (i.e., the current value of the first inductor L1 when the first switch S1 is open); while when the first switch S1 is closed and switches S0 and S1' are open, the amplifier circuit amplifies the voltage across the sampling resistor Rs and converts it through an ADC to obtain the corresponding second digital signal (the current value of the first inductor L1 when the first switch S1 is closed). 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 using the following formula: m2=(I03-I04) / △t2

[0101] Where 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 back on, and Δt2 is the time when the first switch S1 is turned off.

[0102] After determining the current drop slope of the first inductor L1, the drop slope detection subunit 410 can output a compensation adjustment signal Dout based on the current drop slope m2 of the first inductor L1, so as to control the compensation signal output unit 42 to output a 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.

[0103] Referring to FIG17 in some embodiments of this application, FIG17 shows a schematic diagram of a compensation signal output unit 42 in an embodiment of this application. 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 terminal of the first current source IS1 is connected to the power supply terminal, and the output terminal of the first current source IS1 is connected to the second terminal of the first transistor M1. The control terminal of the first transistor M1 is connected to the second terminal of the first transistor M1, the first terminal of the first transistor M1 is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is connected to the ground terminal. The input terminal of the second current source IS2 is connected to the power supply terminal, and the output terminal of the second current source IS2 is connected to the second terminal of the second transistor M2. The control terminal of the second transistor M2 is connected to the second terminal of the second transistor M2. The control terminal of the first transistor M1 is connected to the control terminal of the second transistor M2. The first terminal of the second transistor M2 is connected to the first terminal of the fourth resistor R4. The second terminal of the fourth resistor R4 is connected to the first terminal of the second capacitor C2. The second terminal of the second capacitor C2 is connected to the ground terminal. The first terminal of the second switch S2 is connected to the second terminal of the fourth resistor R4. The second terminal of the second switch S2 is connected to the ground terminal. The first terminal of the third transistor M3 is connected to the power supply terminal. The control terminal of the third transistor M3 is connected to the second terminal of the third transistor M3. The first terminal of the fifth transistor M5 is connected to the second terminal of the third transistor M3. The control terminal of the fifth transistor M5 is connected to the second terminal of the second transistor M2. The first terminal of the fifth transistor M5 is connected to the first terminal of the first transistor M1. The first terminal of the fourth transistor M4 is connected to the power supply terminal. The control terminal of the fourth transistor M4 is connected to the control terminal of the third transistor M3. The second terminal of the fourth transistor M4 is used to output the slope compensation signal Islope.

[0104] It should be noted that when the second switch S2 is open, 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. Therefore, the current flowing through the branch where the second transistor M2 is located gradually decreases, and the control terminal voltage of the fifth transistor M5 (i.e., the drain voltage of the second transistor) gradually increases. The current flowing through the branches 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 a common source and common gate configuration and act as current mirrors for each other, the fourth transistor M4 can output a slope compensation signal Islope with a gradually increasing current. When the second switch S2 is closed, the first terminal of the second transistor M2 is grounded through the fourth resistor R4, and the source voltage of the second transistor M2 decreases and turns on. Since the control terminal of the fifth transistor M5 is connected to the second terminal of the second transistor M2, the conduction of the second transistor M2 will cause the control terminal voltage of the fifth transistor M5 to decrease and turn off. Therefore, the current flowing through the branches where the third transistor M3 and the fifth transistor M5 are located becomes 0. During the alternating closing and opening of the second switch S2, a periodically changing ramp compensation signal Islope is output. At the same time, in Figure 17, when both the ramp compensation signal Islope and the initial ramp signal Isense are input to the fifth resistor R5, the target ramp signal Vramp, which is a voltage signal, can be output at one end of the fifth resistor R5.

[0105] In some embodiments of this application, the compensation adjustment signal Dout can control the mirror ratio between the third transistor M3 and the fourth transistor M4. For example, continuing to refer to FIG17, the compensation adjustment signal Dout can control the number of parallel connections of the fourth transistor M4, thereby changing the mirror ratio between the third transistor M3 and the fourth transistor M4, and ultimately changing the slope of the ramp compensation signal Islope.

[0106] Understandably, 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.

[0107] To better implement the switching power supply circuit in the embodiments of this application, this application also provides a power supply system based on the switching power supply circuit. The power supply system includes the switching power supply circuit as described in any of the above embodiments. Since the power supply system of this application has the switching power supply circuit described in the above embodiments, it possesses all the beneficial effects of the switching power supply circuit in the above embodiments, which will not be repeated here.

[0108] This application also provides an electronic device, which includes a device body and a power supply system as described above disposed within the device body. The electronic device may be, but is not limited to, a weight scale, body fat scale, nutrition scale, infrared electronic thermometer, pulse oximeter, body composition analyzer, power bank, wireless charger, fast charger, car charger, adapter, display, USB (Universal Serial Bus) docking station, stylus, true wireless earphones, car center console screen, automobile, smart wearable device, mobile terminal, and smart home device. Smart wearable devices include, but are not limited to, smartwatches, smart bracelets, and neck massagers. Mobile terminals include, but are not limited to, smartphones, laptops, tablets, and POS (point of sales terminal) machines. Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart robot vacuums, and smart lights.

[0109] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although this application has disclosed preferred embodiments as above, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A switching power supply circuit, characterized in that, include: A switching impedance module, comprising a first inductor and at least one first switch, wherein the switching impedance module is used to receive a first voltage and output a second voltage under the control of a control signal on the first switch; The feedback module is used to output an error signal based on the second voltage and a preset reference voltage; An inductor current detection module is used to output an initial ramp signal based on the rising current of the first inductor. A slope compensation module is used to output a slope compensation signal based on the current drop slope of the first inductor, so as to compensate the initial slope signal and generate a target slope signal. The control module is configured to output the control signal based on the error signal and the target ramp signal; The slope of the ramp compensation signal follows the slope of the current decrease in the first inductor.

2. The switching power supply circuit as described in claim 1, characterized in that, The absolute value of the ratio between the slope of the ramp compensation signal and the slope of the current drop of the first inductor is greater than 0.

5.

3. The switching power supply circuit as described in 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 drop slope of the first inductor and output a compensation adjustment signal corresponding to the current drop 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 as described in claim 3, characterized in that, The compensation and adjustment unit includes an analog-to-digital converter, a rising slope logic calculation unit, an inductor logic calculation unit, and a falling slope logic calculation unit. The analog-to-digital converter is used to detect the magnitude of the current in the first inductor during the rise of the first inductor current, and to detect the magnitude of the first voltage. The rising slope logic calculation unit is used to determine the rising slope of the first inductor current based on the amount of current change during the rising period of the first inductor current. The inductor logic calculation unit is used to determine the inductance value of the first inductor based on the first voltage and the current rise slope. The descent slope logic calculation unit is used to determine the current descent slope of the first inductor based on the inductance value of the first inductor, the first voltage, and the second voltage.

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

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

7. The switching power supply circuit as described in 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 terminal of the first current source is connected to the power supply terminal, and the output terminal of the first current source is connected to the second terminal of the first transistor. The control terminal of the first transistor is connected to the second terminal of the first transistor, the first terminal of the first transistor is connected to the first terminal of the third resistor, and the second terminal of the third resistor is connected to the ground terminal. The input terminal of the second current source is connected to the power supply terminal, and the output terminal of the second current source is connected to the second terminal of the second transistor. The control terminal of the second transistor is connected to the control terminal of the first transistor, the first terminal of the second transistor is connected to the first terminal of the fourth resistor, the second terminal of the fourth resistor is connected to the first terminal of the second capacitor, and the second terminal of the second capacitor is connected to the ground terminal. The first terminal of the second switch is connected to the second terminal of the fourth resistor, and the second terminal of the second switch is connected to the ground terminal; The first terminal of the third transistor is connected to the power supply terminal, and the control terminal of the third transistor is connected to the second terminal of the third transistor. The second terminal of the fifth transistor is connected to the second terminal of the third transistor, the control terminal of the fifth transistor is connected to the second terminal of the second transistor, and the first terminal of the fifth transistor is connected to the first terminal of the first transistor. The first terminal of the fourth transistor is connected to the power supply terminal, the control terminal of the fourth transistor is connected to the control terminal of the third transistor, and the second terminal of the fourth transistor is used to output the ramp compensation signal.

8. The switching power supply circuit as described in 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 as described in 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 connect to 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 terminal; The first input terminal of the first operational amplifier is connected to the first node between the first resistor and the second resistor, the second input terminal of the first operational amplifier is used to connect to 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 as described in claim 1, characterized in that, The control module includes a first comparator and an RS flip-flop; The first input terminal of the first comparator is used to receive the error signal, and the second input terminal of the first comparator is used to receive the target ramp signal; The first input terminal of the RS flip-flop is connected to the output terminal of the first comparator, the second input terminal of the RS flip-flop is used to receive a preset clock signal, and the output terminal of the RS flip-flop is connected to the control terminal of the first switch.

11. A power supply system, characterized in that, Includes the switching power supply circuit as described in any one of claims 1 to 10.

12. An electronic device, characterized in that, Including the power supply system as described in claim 11.

Images