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 inductor module, the switching inductor module comprises a first inductor and a first switch, and the first switch is used for controlling the first inductor to charge or discharge; the current detection module is used for outputting sensing current according to the current of the first inductor, and the size of the sensing current is in direct proportion to the size of the current of the first inductor; and the current detection and calibration module is used for calibrating the current detection module, so that the ratio of the sensing current to the current of the first inductor is equal to a preset ratio. The current detection and calibration module is used for calibrating the current detection module, so that the ratio of the sensing current to the inductive current is equal to the preset ratio, and the phenomenon that the detection value of the actual circuit current of the current detection module has large deviation compared with the design value can be avoided.

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 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 voltage control mode.

[0003] In the related art, the DC-DC converter in 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. In the current feedback loop, it is necessary to collect the inductor current signal to generate a ramp voltage signal, so as to generate a PWM control signal according to the ramp voltage signal combined with the error signal output by the voltage feedback loop, and finally use the PWM control signal to control the switching circuit.

[0004] However, since many irrational factors are introduced during the design and manufacturing process of the circuit, such as PVT factors (process, voltage and temperature factors), mismatch factors, parasitics and stress, the current detection value of the actual current feedback loop has a large deviation from the design value, and the deviation may reach ±30%, which may not only cause a reduction in load capacity but also cause damage to the circuit. Summary of the invention

[0005] 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.

[0006] In a first aspect, an embodiment of the present application provides a switching power supply circuit, comprising:

[0007] A switch inductor module, the switch inductor module includes a first inductor and a first switch, the first switch is used to control the charging or discharging of the first inductor;

[0008] A current detection module, the current detection module is used to sense current according to the current output of the first inductor, and the magnitude of the sensed current is proportional to the magnitude of the current of the first inductor;

[0009] The current detection calibration module is used to calibrate the current detection module so that the ratio of the sensed current to the current of the first inductor is equal to a preset ratio.

[0010] In a second aspect, an embodiment of the present application further provides a power supply system, comprising the above-mentioned switching power supply circuit.

[0011] 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.

[0012] The present application utilizes a current detection module to detect the current of the first inductor and output a sensed current. Since the magnitude of the sensed current is proportional to the magnitude of the current of the first inductor, the sensed current can be used as a current loop feedback signal to generate a PWM signal for controlling the first switch, or the sensed current can also be used as an overcurrent protection (OCP) to determine that the first inductor has an overcurrent phenomenon, thereby ensuring the normal operation of the switching power supply circuit and avoiding damage. Since the current detection calibration module can calibrate the current detection module so that the ratio between the sensed current and the current of the first inductor is equal to a preset ratio, that is, after the current detection calibration module calibrates the current detection module, the current detection value of the current detection module can be made close to the ideal design value, thereby avoiding the phenomenon that the current detection value of the actual circuit of the current detection module has a large deviation from the design value.

[0013] 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

[0014] 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.

[0015] Figure 1 A schematic diagram of a DC-DC converter in the related art is shown.

[0016] Figure 2 A schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0017] Figure 3 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0018] Figure 4 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0019] Figure 5Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0020] Figure 6 A schematic diagram of a current detection module in an embodiment of the present application is shown.

[0021] Figure 7 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0022] Figure 8 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0023] Fig. 9 A schematic diagram of a current detection calibration module in an embodiment of the present application is shown.

[0024] Fig.10 Another schematic diagram of the current detection calibration module in the embodiment of the present application is shown.

[0025] Fig.11 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0026] Fig.12 Another schematic diagram of a switching power supply circuit in an embodiment of the present application is shown.

[0027] Among them, 10 is a switch inductor module, 20 is a current detection module, 30 is a current detection calibration module, 31 is a current output unit, 32 is a detection calibration unit, 321 is a current comparison subunit, 322 is a calibration subunit, 40 is a voltage feedback module, 50 is a control module, and 60 is a slope compensation module;

[0028] A first voltage AVDD, a second voltage VBST, a first switch S1, a first inductor L1, a first capacitor C1, a sensing current Isense, a preset reference voltage Vref, an error signal Vea, a control signal Vd, a first diode D1, an error amplifier OP, a first feedback resistor RF1, a second feedback resistor RF2, a comparator COMP, a ramp signal Vramp, a preset clock signal CLK, a first calibration current I_test, and a second calibration current Isense_test;

[0029] A first transistor M01, a first resistor R01, a first current source IS01, a second transistor M02, a second resistor R02, a second current source IS02, a third transistor M03, a third resistor R03, a fourth transistor M04, a fifth transistor M05, a sixth transistor M06, a first comparator COMP1, a second comparator COMP2, a standard resistor RS, a first reference voltage Vref-, a second reference voltage Vref+, a standard current source IS0, and an output transistor M1. DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] It should be noted that, in the embodiments of the present application, "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] At present, the peak current control mode DC-DC converter is a 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 connected to a power supply terminal VDD, a diode D0, a voltage-stabilizing capacitor C0 of an output voltage Vout, and a transistor MN1, and the feedback control circuit is composed of a current detection circuit, a resistor R3, a feedback resistor R1, a feedback resistor R2, an operational amplifier OP, a comparator COMP, and a logic drive circuit connected to a clock signal CLK.

[0041] In the feedback control circuit, the inverting input terminal of the operational amplifier OP is connected between the feedback resistor R1 and the feedback resistor R2, the non-inverting input terminal of the operational amplifier OP is connected to the reference voltage Vref, the feedback resistor R1, the feedback resistor R2 and the operational amplifier OP form a voltage feedback loop, and output the error signal Verror to the inverting input terminal of the comparator COMP; the current detection circuit can output the amplified current signal I1 during the rising period of the inductor L0 current, the amplified current signal I1 generates a ramp signal Vra through the resistor R3, and the ramp signal Vra is input to the non-inverting input terminal of the comparator, finally forming a dual-loop feedback control circuit of the voltage loop and the current loop.

[0042] However, since many irrational factors are introduced during the design and manufacturing process of the circuit, such as PVT factors (process, voltage and temperature factors), mismatch factors, parasitics and stress, the current detection value of the actual current detection circuit produced has a large deviation from the design value, and the deviation may reach as much as ±30%, which may not only cause a reduction in the load capacity of the DC-DC converter, but also cause damage to the circuit under the influence of extreme deviations.

[0043] 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.

[0044] First, see Figure 2 , Figure 2 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 inductor module 10, a current detection module 20 and a current detection calibration module 30.

[0045] Specifically, the switch inductor module 10 is used to access the first voltage AVDD and output the second voltage VBST under the control of the control signal Vd. 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 inductor module 10 may include a boost circuit so that the switch inductor module 10 outputs a second voltage VBST with a higher voltage according to the first voltage AVDD; for another example, the switch inductor module 10 may include a buck circuit so that the switch inductor module 10 outputs a second voltage VBST with a lower voltage according to the first voltage AVDD.

[0046] In some embodiments of the present application, the switch inductor module 10 can be controlled based on a peak current control mode, and the control circuit of the switch inductor module 10 includes a current loop and a voltage loop feedback control loop. In some embodiments of the present application, the switch inductor module 10 can also be controlled based on a voltage control mode, and the control circuit of the switch inductor module 10 includes a voltage loop feedback control loop, etc.

[0047] It should be noted that the switched inductor module 10 includes a first inductor L1, a first capacitor C1 and at least one first switch S1. The first switch S1 is used to control the charging or discharging of the first inductor L1. 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 boost circuit and the BUCK buck circuit.

[0048] For example, taking the BOOST boost circuit as an example, refer to Figure 3 , Figure 3 Another 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 Vd, 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.

[0049] When the control signal Vd 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 Vd 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.

[0050] For another example, taking the BUCK step-down circuit as an example, refer to Figure 4 , Figure 4 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.

[0051] When the control signal Vd 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 Vd 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.

[0052] Understandably, the above Figure 3 as well as Figure 4 As only an exemplary embodiment of the switch inductor module 10 of the present application, those skilled in the art can make equivalent modifications to the switch inductor module 10 under the guidance of the present application. For example, the switch inductor module 10 can also include a Buck-Boost step-up and step-down circuit. For another example, refer to Figure 5 , Figure 5 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 the first switch S1'. It only needs to invert the control signal Vd and input it into the control end of the first switch S1'.

[0053] The current detection module 20 is used to output a sensing current Isense according to the current Iin of the first inductor L1 of the switching inductor module 10. The magnitude of the sensing current Isense is proportional to the magnitude of the current Iin of the first inductor L1. Generally, the magnitude of the sensing current Isense is smaller than the magnitude of the current Iin of the first inductor L1. For example, the ratio of the magnitude of the sensing current Isense to the current Iin of the first inductor L1 is fixed at 1:12000, so as to reduce the power consumption and design difficulty of the current detection module 20.

[0054] In some embodiments of the present application, for example, in an embodiment where the switch inductor module 10 is controlled based on a peak current control mode, the sensed current Isense can be used as a feedback signal of a current loop feedback loop, so that the control circuit of the switch inductor module 10 generates a control signal Vd based on the sensed current Isense. In some embodiments of the present application, for example, in an embodiment where the switch inductor module 10 can be controlled based on a voltage control mode, the sensed current Isense can also be used as a detection current for overcurrent protection (OCP) judgment to avoid overcurrent in the first inductor L1.

[0055] As an example, see Figure 6 , Figure 6A schematic diagram of a current detection module 20 in an embodiment of the present application is shown, wherein the current detection module 20 includes a first transistor M01, a first resistor R01, a first current source IS01, a second transistor M02, a second resistor R02, a second current source IS02, a third transistor M03, a third resistor R03, a fourth transistor M04, a fifth transistor M05 and a sixth transistor M06; a first end of the first transistor M01 is connected to a first inductor L1, and a control end of the first transistor M01 is used to access a control signal Vd; a first end of the first resistor R01 is connected to a second end of the first transistor M01, and a second end of the first resistor R01 is connected to a ground end; an input end of the first current source IS01 is connected to a power supply end VDD, and an output end of the first current source IS01 is connected to a first end of the second transistor M02; a control end of the second transistor M02 is connected to a control end of the third transistor M03, a first end of the second resistor R02 is connected to a second end of the second transistor M02, and a second end of the second resistor R02 is connected to a first The second end of the transistor M01 is connected; the input end of the second current source IS02 is connected to the power supply terminal VDD, the output end of the second current source IS02 is connected to the first end of the third transistor M03, and the first end of the third transistor M03 is connected to the control end of the third transistor M03; the first end of the third resistor R03 is connected to the second end of the third transistor M03, and the second end of the third resistor R03 is connected to the ground end; the second end of the fifth transistor M05 is connected to the power supply terminal VDD, the control end of the fifth transistor M05 is connected to the first end of the fifth transistor M05, and the first end of the fifth transistor M05 is connected to the first end of the fourth transistor M04; the control end of the fourth transistor M04 is connected to the first end of the second transistor M02, and the second end of the fourth transistor M04 is connected to the second end of the third transistor M03; the second end of the sixth transistor M06 is connected to the power supply terminal VDD, the control end of the sixth transistor M06 is connected to the control end of the fifth transistor M05, and the first end of the sixth transistor M06 is used to output the sensing current Isense.

[0056] It should be noted that in Figure 6 In the example, the source voltage of the second transistor M02 and the source voltage of the third transistor M03 can be calculated according to the following formula:

[0057] VS2=I01*R02+(Iin+I01)*R01

[0058] VS3=I02*R03+I_M04*R03

[0059] Among them, VS2 is the source voltage of the second transistor M02, VS3 is the source voltage of the third transistor M03, Iin is the inductor current, I01 is the current output by the first current source IS01, I02 is the current output by the second current source IS02, and I_M04 is the output current of the fourth transistor M04.

[0060] Since the second transistor M02 and the third 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:

[0061] I01*R02+Iin*R01=I02*R03+I_M04*R03

[0062] When the currents output by the first current source IS01 and the second current source IS02 are equal, and the resistance values ​​of the second resistor R02 and the third resistor R03 are equal, it can be seen that the current flowing through the fourth transistor M04 satisfies the following relationship:

[0063] I_M04=Iin*R01 / R02

[0064] At the same time, since the current mirror flowing through the fifth transistor M05 is equal to the current flowing through the fourth transistor M04, and the fifth transistor M05 and the sixth transistor M06 are current mirrors of each other, assuming that the mirror ratio between the fifth transistor M05 and the sixth transistor M06 is k, the second end output sensing current Isense of the sixth transistor M06 satisfies the following relationship:

[0065] Isense=k*Iin*R01 / R02

[0066] It can be seen that by setting the coefficient k in the above formula and or the ratio of R01 / R02, the amplification / reduction factor of the sensing current Isense relative to the rising current of the first inductor L1 can be adjusted, and the magnitude of the sensing current Isense is proportional to the magnitude of the current Iin of the first inductor L1.

[0067] It should be noted that due to the influence of PVT factors (process, voltage and temperature factors), mismatch factors, parasitics and stress, the ratio of the sensing current Isense output by the current detection module 20 to the current Iin of the first inductor L1 may deviate from the design value. For example, for an embodiment in which the current detection module 20 outputs the sensing current Isense according to the current Iin of the first inductor L1 at a ratio of 1:12000 to the design value, the actual ratio of the sensing current Isense output by the current detection module 20 to the current Iin of the first inductor L1 may be 1:10000, which may cause a reduction in the load capacity of the switching power supply circuit and may cause circuit damage under the influence of extreme deviations.

[0068] In the embodiment of the present application, the current detection calibration module 30 can calibrate the current detection module 20, so that the ratio of the sensing current Isense output by the current detection module 20 to the current Iin of the first inductor L1 can be equal to a preset ratio. For example, for the above-mentioned embodiment in which the ratio of the sensing current Isense output by the actual current detection module 20 to the current Iin of the first inductor L1 is 1:10000, after the current detection calibration module 30 calibrates the current detection module 20, the switching inductor module 10 can output the sensing current Isense according to the current Iin of the first inductor L1 at a ratio of 1:12000.

[0069] In some embodiments of the present application, the current detection calibration module 30 can detect the magnitude of the current Iin of the first inductor L1 and the magnitude of the sensing current Isense through an analog-to-digital converter, and then determine whether the ratio of the sensing current Isense output by the current detection module 20 to the current Iin of the first inductor L1 is equal to a preset ratio. If it is not equal to the preset ratio, the current detection module 20 can be calibrated so that the ratio of the sensing current Isense output by the current detection module 20 to the current Iin of the first inductor L1 is equal to the preset ratio. In other embodiments of the present application, the current detection calibration module 30 can input a standard current of known magnitude to the current detection module 20, and then measure the magnitude of the sensing current Isense, and determine whether to calibrate the current detection module 20 by determining whether the ratio of the sensing current Isense output by the current detection module 20 to the standard current is equal to the preset ratio.

[0070] In some embodiments of the present application, for example, the current detection module 20 includes: Figure 6In the embodiment of the circuit shown, the current detection calibration module 30 can control the size of the first resistor R01. Combining the calculation formula of the sensing current Isense and the current Iin of the first inductor L1, Isense=k*Iin*R01 / R02, it can be known that controlling the size of the first resistor R01 can change the ratio of the sensing current Isense to the current Iin of the first inductor L1 to a preset ratio, thereby realizing the calibration of the current detection module 20.

[0071] In some embodiments of the present application, for example, the current detection module 20 includes: Figure 6 In the embodiment of the circuit shown, the current detection calibration module 30 can control the sizes of the second resistor R02 and the third resistor R03. Combining the calculation formula of the sensing current Isense and the current Iin of the first inductor L1, Isense=k*Iin*R01 / R02, it can be known that by controlling the size of the second resistor R02, the ratio of the sensing current Isense to the current Iin of the first inductor L1 can be changed to a preset ratio, thereby realizing the calibration of the current detection module 20.

[0072] In some embodiments of the present application, for example, the current detection module 20 includes: Figure 6 In the embodiment of the circuit shown, the current detection calibration module 30 can control the mirror ratio of the fifth transistor M05 and the sixth transistor M06. Combining the calculation formula of the sensing current Isense and the current Iin of the first inductor L1, Isense=k*Iin*R01 / R02, it can be known that controlling the mirror ratio of the fifth transistor M05 and the sixth transistor M06 (i.e., the coefficient k) can change the ratio of the sensing current Isense to the current Iin of the first inductor L1 to a preset ratio, thereby realizing the calibration of the current detection module 20.

[0073] In the embodiment of the present application, since the current detection calibration module 30 can calibrate the current detection module 20, the ratio of the sensing current Isense to the current Iin of the first inductor L1 is equal to the preset ratio. That is to say, after the current detection calibration module 30 calibrates the current detection module 20, the detection value of the actual circuit current of the current detection module 20 can be made close to the ideal design value, thereby avoiding the phenomenon that the detection value of the actual circuit current of the current detection module 20 has a large deviation compared with the design value.

[0074] In some embodiments of the present application, see Figure 7 , Figure 7Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, wherein the current detection calibration module 30 includes a current output unit 31 and a detection calibration unit 32; the current output unit 31 is used to input a first calibration current I_test to the current detection module 20, so that the current detection module 20 outputs a second calibration current Isense_test according to the first calibration current I_test; the detection calibration unit 32 is used to calibrate the current detection module 20 until the ratio between the second calibration current Isense_test and the first calibration current I_test is equal to the preset ratio when the ratio between the second calibration current Isense_test and the first calibration current I_test is not equal to the preset ratio.

[0075] It should be noted that during the calibration process, the switch inductor module 10 does not output the current Iin of the first inductor L1 to the current detection module 20, but the current output unit 31 outputs the first calibration current I_test to the current detection module 20 (for example, the current output unit 31 inputs the first calibration current I_test to the first end of the first transistor M01 in the on state), so the current detection module 20 can output the second calibration current Isense_test according to the first calibration current I_test. After the current detection module 20 outputs the second calibration current Isense_test, the detection calibration unit 32 can determine whether the ratio between the second calibration current Isense_test and the first calibration current I_test is equal to the preset ratio. If the ratio between the second calibration current Isense_test and the first calibration current I_test is not equal to the preset ratio, the detection calibration unit 32 can calibrate the current detection module 20 until the ratio between the second calibration current Isense_test and the first calibration current I_test is equal to the preset ratio.

[0076] For example, for an embodiment in which the calculation formula of the sensing current Isense and the current Iin of the first inductor L1 satisfies the formula Isense=k*Iin*R01 / R02, the detection calibration unit 32 can change the resistance value of the first resistor R01, or change the resistance values ​​of the second resistor R02 and the third resistor R03, or change the mirror ratio k of the fifth transistor M05 and the sixth transistor M06, so that the ratio between the second calibration current Isense_test and the first calibration current I_test is equal to the preset ratio.

[0077] Exemplarily, the detection calibration unit 32 may include an analog-to-digital converter, which measures the magnitude of the second calibration current Isense_test and determines whether the ratio of the second calibration current Isense_test to the first calibration current I_test is equal to a preset ratio.

[0078] In some embodiments of the present application, see Figure 8 , Figure 8 Another schematic diagram of the switching power supply circuit in the embodiment of the present application is shown, and the detection calibration unit 32 includes a current comparison subunit 321 and a calibration subunit 322; the current comparison subunit 321 is used to determine whether the second calibration current Isense_test is greater than the first preset current value and less than the second preset current value; the calibration subunit 322 is used to calibrate the current detection module 20 until the second calibration current Isense_test is greater than the first preset current value and less than the second preset current value when the second calibration current Isense_test is less than the first preset current value or the second calibration current Isense_test is greater than the second preset current value; wherein the product of the first calibration current I_test and the preset ratio is greater than the first preset current value and less than the second preset current value.

[0079] It should be noted that, since the product of the first calibration current I_test and the preset ratio is greater than the first preset current value and less than the second preset current value, the following relationship is satisfied:

[0080] I1 <I_test*K0<I2

[0081] Wherein, K0 is a preset coefficient, I1 is a first preset current value, and I2 is a second preset current value.

[0082] It can be seen that:

[0083]

[0084] Then, when the second calibration current Isense_test is less than the first preset current value, it can be known that:

[0085]

[0086] Therefore, when the second calibration current Isense_test is less than the first preset current value, it means that the ratio of the second calibration current Isense_test to the first calibration current I_test is less than the preset ratio. Therefore, the calibration subunit 322 can calibrate the current detection module 20 until the second calibration current Isense_test is greater than the first preset current value. For example, for an embodiment in which the calculation formula of the sensing current Isense and the current Iin of the first inductor L1 satisfies the formula Isense=k*Iin*R01 / R02, the calibration subunit 322 can increase the resistance of the first resistor R01, or reduce the resistance of the second resistor R02 and the third resistor R03, or increase the mirror ratio k of the fifth transistor M05 and the sixth transistor M06.

[0087] On the contrary, when the second calibration current Isense_test is greater than the first preset current value, it can be known that:

[0088]

[0089] Therefore, when the second calibration current Isense_test is greater than the second preset current value, it means that the ratio of the second calibration current Isense_test to the first calibration current I_test is greater than the preset ratio. Therefore, the calibration subunit 322 can calibrate the current detection module 20 until the second calibration current Isense_test is less than the second preset current value. For example, for an embodiment in which the calculation formula of the sensing current Isense and the current Iin of the first inductor L1 satisfies the formula Isense=k*Iin*R01 / R02, the calibration subunit 322 can reduce the resistance of the first resistor R01, or increase the resistance of the second resistor R02 and the third resistor R03, or reduce the mirror ratio k of the fifth transistor M05 and the sixth transistor M06.

[0090] It can be seen that the calibration subunit 322 can calibrate the current detection module 20 until the second calibration current Isense_test is greater than the first preset current value and less than the second preset current value. At this time, it can be considered that the ratio of the second calibration current Isense_test to the first calibration current I_test is approximately equal to the preset ratio. When the current detection module 20 works normally, it can be ensured that the ratio of the sensing current Isense to the current Iin of the first inductor L1 is approximately equal to the preset ratio.

[0091] It can be understood that the calibration subunit 322 of the present application can be a logic circuit composed of various gate circuits, triggers, registers, etc., and the present application does not make any specific limitation.

[0092] In some embodiments of the present application, when the second calibration current Isense_test is less than the first preset current value, the calibration subunit 322 controls the second calibration current Isense_test output by the current detection module 20 to increase once at every preset time interval until the second calibration current Isense_test is greater than the first preset current value; when the second calibration current Isense_test is greater than the second preset current value, the calibration subunit 322 controls the second calibration current Isense_test output by the current detection module 20 to decrease once at every preset time interval until the second calibration current Isense_test is less than the second preset current value.

[0093] For example, taking the calculation formula of the sensing current Isense and the current Iin of the first inductor L1 satisfying the formula Isense=k*Iin*R01 / R02 as an example, when the second calibration current Isense_test is less than the first preset current value, the calibration subunit 322 controls the mirror ratio k of the fifth transistor M05 and the sixth transistor M06 to increase once every preset time interval. For example, after the mirror ratio k increases from 1 to 1.1, if the second calibration current Isense_test is still less than the first preset current value, the calibration subunit 322 controls the current after the preset time interval. The mirror ratio k of the detection module 20 continues to increase from 1.1 to 1.2, so that the second calibration current Isense_test output by the current detection module 20 continues to increase; if the second calibration current Isense_test is still less than the first preset current value, the calibration subunit 322 controls the mirror ratio k of the current detection module 20 to continue to increase from 1.2 to 1.3 after an interval of a preset time, so that the second calibration current Isense_test output by the current detection module 20 continues to increase, and so on, until the second calibration current Isense_test is greater than the first preset current value.

[0094] On the contrary, when the second calibration current Isense_test is greater than the second preset current value, the calibration subunit 322 controls the mirror ratio k of the fifth transistor M05 and the sixth transistor M06 to decrease once every preset time interval. For example, after the mirror ratio k is reduced from 1 to 0.9, if the second calibration current Isense_test is still greater than the second preset current value, the calibration subunit 322 controls the mirror ratio k of the current detection module 20 to continue to decrease from 0.9 to 0.8 after the preset time interval, so that the second calibration current Isense_test output by the current detection module 20 continues to decrease; if the second calibration current Isense_test is still greater than the second preset current value, the calibration subunit 322 controls the mirror ratio k of the current detection module 20 to continue to decrease from 0.8 to 0.7 after the preset time interval, so that the second calibration current Isense_test output by the current detection module 20 continues to decrease, and so on, until the second calibration current Isense_test is less than the second preset current value.

[0095] It can be understood that the above embodiment uses multiple calibrations to make the second calibration current Isense_test greater than the first preset current value and less than the second preset current value. In some possible embodiments, when the second calibration current Isense_test is less than the first preset current value or greater than the second preset current value, the calibration subunit 322 may also calibrate the current detection module 20 once to make the second calibration current Isense_test greater than the first preset current value and less than the second preset current value.

[0096] In some embodiments of the present application, see Fig. 9 , Fig. 9 A schematic diagram of the current detection calibration module 30 in an embodiment of the present application is shown, wherein the current comparison subunit 321 includes a first comparator COMP1, a second comparator COMP2 and a standard resistor RS; the inverting input terminal of the first comparator COMP1 is used to access the first reference voltage Vref-, and the non-inverting input terminal of the first comparator COMP1 is connected to the first end of the standard resistor RS; the inverting input terminal of the second comparator COMP2 is used to access the second reference voltage Vref+, and the non-inverting input terminal of the second comparator COMP2 is connected to the first end of the standard resistor RS; the first end of the standard resistor RS is used to access the second calibration current Isense_test, and the second end of the standard resistor RS is connected to the ground terminal; wherein the output terminal of the first comparator COMP1 is connected to the calibration subunit 322, and the output terminal of the second comparator COMP2 is connected to the calibration subunit 322.

[0097] It should be noted that the resistance value of the standard resistor RS is known. When the second calibration current Isense_test flows into the ground terminal through the standard resistor RS, a corresponding voltage signal Isense_test*RS can be generated at the first end of the standard resistor RS. The first comparator COMP1 and the second comparator COMP2 are used to compare the voltage signal Isense_test*RS with respect to the first reference voltage Vref- and the second reference voltage Vref+, so as to determine whether the second calibration current Isense_test is greater than the first preset current value and less than the second preset current value.

[0098] For example, when the output ends of the first comparator COMP1 and the second comparator COMP2 both output low-level signals, it means that the voltage signal Isense_test*RS is less than the first reference voltage Vref- and is also less than the second reference voltage Vref+, that is, at this time, it can be considered that the second calibration current Isense_test is less than the first preset current value. Therefore, the calibration subunit 322 can control the current detection module 20 to increase the second calibration current Isense_test, for example, the mirror ratio k of the fifth transistor M05 and the sixth transistor M06 is controlled to increase once at every preset time interval until the first comparator COMP1 outputs a high-level signal and the output end of the second comparator COMP2 outputs a low-level signal, indicating that the voltage signal Isense_test*RS is greater than the first reference voltage Vref- and less than the second reference voltage Vref+. At this time, it can be considered that the second calibration current Isense_test is greater than the first preset current value and less than the second preset current value.

[0099] For another example, when the output ends of the first comparator COMP1 and the second comparator COMP2 both output high-level signals, it means that the voltage signal Isense_test*RS is greater than the first reference voltage Vref- and is also greater than the second reference voltage Vref+, that is, at this time, it can be considered that the second calibration current Isense_test is greater than the second preset current value, so the calibration subunit 322 can control the current detection module 20 to reduce the second calibration current Isense_test, for example, the mirror ratio k of the fifth transistor M05 and the sixth transistor M06 is controlled to decrease once every preset time interval, the first comparator COMP1 outputs a high-level signal, and the output end of the second comparator COMP2 outputs a low-level signal, indicating that the voltage signal Isense_test*RS is greater than the first reference voltage Vref- and less than the second reference voltage Vref+, at this time, it can be considered that the second calibration current Isense_test is greater than the first preset current value and less than the second preset current value.

[0100] In some embodiments of the present application, see Fig.10 , Fig.10 Another schematic diagram of the current detection calibration module 30 in the embodiment of the present application is shown, wherein the current output unit 31 includes a standard current source IS0 and an output transistor M1; the input end of the standard current source IS0 is connected to the power supply end, the output end of the standard current source IS0 is connected to the first end of the output transistor M1, the second end of the output transistor M1 is connected to the current detection module 20, and the control end of the output transistor M1 is connected to the calibration subunit 322. Specifically, the standard current source IS0 can provide a first calibration current I_test, and the calibration subunit 322 can control whether the output transistor M1 is turned on, thereby controlling whether the standard current source IS0 provides the first calibration current I_test to the current detection module 20, so as to start the calibration process of the current detection module 20.

[0101] In some embodiments of the present application, Figure 6 as well as Fig.10 , the second end of the output transistor M1 is connected to the first end of the first resistor R01, and the size of the first transistor M01 is equal to that of the output transistor M1, that is, the oxide thickness (tox), the channel length (L) and the transistor width (W) of the first transistor M01 and the output transistor M1 are all equivalent, then the first calibration current I_test output by the output transistor M1 can be considered as the current Iin of the first inductor L1 output by the first transistor M01, thereby realizing the calibration of the current detection module 20 under the condition of simulating the current Iin of the real first inductor L1.

[0102] In some embodiments of the present application, for example, for an embodiment in which the switch inductor module 10 is controlled based on a peak current control mode, see Fig.11 , Fig.11 Another schematic diagram of the switching power supply circuit in the embodiment of the present application is shown. The switching power supply circuit also includes a voltage feedback module 40 and a control module 50. The current detection module 20, the voltage feedback module 40 and the control module 50 constitute a control circuit of the switching inductor module 10.

[0103] Specifically, the voltage feedback module 40 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. The voltage feedback module 40 includes a first feedback resistor RF1, a second feedback resistor RF2 and an error amplifier OP; the first end of the first feedback resistor RF1 is used to access the second voltage VBST, the second end of the first feedback resistor RF1 is connected to the first end of the second feedback resistor RF2, and the second end of the second feedback resistor RF2 is connected to the ground; the first input end of the error amplifier OP is connected to the first node m1 between the first feedback resistor RF1 and the second feedback resistor RF2, the second input end of the error amplifier OP is used to access the preset reference voltage Vref, and the output end of the error amplifier OP is used to output the error signal Vea.

[0104] The control module 50 may output a control signal Vd according to the error signal Vea and the sense current Isense, so as to control the first switch S1 in the switch inductor module 10 through the control signal Vd, and enable the switch inductor module 10 to output a second voltage VBST according to the first voltage AVDD.

[0105] For example, Fig.11 Taking the switching inductor module 10 including a BOOST boost circuit as an example, when the voltage corresponding to the sensing current Isense 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, so the control module 50 can output a low-level control signal Vd and disconnect the first switch S1, 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 second voltage VBST with a higher voltage can be output.

[0106] During the discharge process of the first inductor L1, since the voltage corresponding to the sensing current Isense is smaller 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 Vd and turn on the first switch S1. Therefore, the first voltage AVDD charges the first inductor L1, and the current of the first inductor L1 gradually increases. The first capacitor C1 discharges and outputs the second voltage VBST until the voltage corresponding to the sensing current Isense is larger than the voltage of the error signal Vea, and the above process is repeated.

[0107] As an exemplary embodiment, see Fig.11 The control module 50 includes a comparator COMP and a logic drive circuit; the first input terminal of the comparator COMP is used to access the error signal Vea, and the second input terminal of the comparator COMP is used to access the ramp signal Vramp generated based on the sensing current Isense; the first input terminal of the logic drive circuit is connected to the output terminal of the comparator COMP, the second input terminal of the logic drive circuit is used to access the preset clock signal CLK, and the output terminal of the logic drive circuit is connected to the control terminal of the first switch S1.

[0108] exist Fig.11 In the embodiment, the sensing current Isense flows into the ground terminal through the resistor Rr to generate the ramp signal Vramp. When the voltage of the ramp signal Vramp is greater than the voltage of the error signal Vea, the preset clock signal CLK is at a low level, the comparator COMP outputs a high level signal, and the output end of the logic drive circuit can output a low level signal and control the first switch S1 to be turned off; after the first switch S1 is turned off, the comparator COMP outputs a low level signal, and when the rising edge of the preset clock signal CLK arrives, the output end of the logic drive circuit can output a high level signal and control the first switch S1 to be turned on.

[0109] 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 design of the control module 50. For example, the logic drive circuit usually includes an RS trigger, but in some possible embodiments, logic circuits such as logic gates and triggers can also be used to replace the RS trigger.

[0110] It is worth noting that the above contents about the switching power supply circuit are intended to clearly illustrate the implementation verification process of the present application. Those skilled in the art can make equivalent modified designs or further designs under the guidance of the present application, for example, refer to Fig.12 , Fig.12 Another schematic diagram of the switching power supply circuit in an embodiment of the present application is shown, wherein the switching power supply circuit may further include a slope compensation module 60 that outputs a slope current compensation signal Islope to avoid subharmonic oscillation when the duty cycle of the PWM signal is greater than 50%.

[0111] 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.

[0112] 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.

[0113] 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 inductor module, the switch inductor module comprising a first inductor and a first switch, the first switch being used to control charging or discharging of the first inductor; A current detection module, the current detection module is used to sense current according to the current output of the first inductor, the magnitude of the sensed current is proportional to the magnitude of the current of the first inductor; A current detection calibration module is used to calibrate the current detection module so that the ratio of the sensing current to the current of the first inductor is equal to a preset ratio.

2. The switching power supply circuit according to claim 1, characterized in that: The current detection and calibration module includes a current output unit and a detection and calibration unit; The current output unit is used to input a first calibration current to the current detection module, so that the current detection module outputs a second calibration current according to the first calibration current; The detection calibration unit is used for calibrating the current detection module until the ratio between the second calibration current and the first calibration current is equal to the preset ratio when the ratio between the second calibration current and the first calibration current is not equal to the preset ratio.

3. The switching power supply circuit according to claim 2, characterized in that: The detection and calibration unit includes a current comparison subunit and a calibration subunit; The current comparison subunit is used to determine whether the second calibration current is greater than the first preset current value and less than the second preset current value; The calibration subunit is used for calibrating the current detection module until the second calibration current is greater than the first preset current value and less than the second preset current value when the second calibration current is less than the first preset current value or the second calibration current is greater than the second preset current value; The product of the first calibration current and the preset ratio is greater than the first preset current value and less than the second preset current value.

4. The switching power supply circuit according to claim 3, characterized in that: When the second calibration current is less than the first preset current value, the calibration subunit controls the second calibration current output by the current detection module to increase once every preset time interval until the second calibration current is greater than the first preset current value; When the second calibration current is greater than a second preset current value, the calibration subunit controls the second calibration current output by the current detection module to decrease once at every preset time interval until the second calibration current is less than the second preset current value.

5. The switching power supply circuit according to claim 3, characterized in that: The current comparison subunit includes a first comparator, a second comparator and a standard resistor; The inverting input terminal of the first comparator is used to access the first reference voltage, the non-inverting input terminal of the first comparator is connected to the first end of the standard resistor, and the output terminal of the first comparator is connected to the calibration subunit; The inverting input terminal of the second comparator is used to access the second reference voltage, the non-inverting input terminal of the second comparator is connected to the first end of the standard resistor, and the output terminal of the second comparator is connected to the calibration subunit; The first end of the standard resistor is used to access the second calibration current, and the second end of the standard resistor is connected to the ground.

6. The switching power supply circuit according to claim 2, characterized in that: The current output unit includes a standard current source and an output transistor; The input end of the standard current source is connected to the power supply end, the output end of the standard current source is connected to the first end of the output transistor, the second end of the output transistor is connected to the current detection module, and the control end of the output transistor is connected to the calibration subunit.

7. The switching power supply circuit according to claim 6, characterized in that: The current detection module includes a first transistor, a first resistor, a first current source, a second transistor, a second resistor, a second current source, a third transistor, a third resistor, a fourth transistor, a fifth transistor and a sixth transistor; The first end of the first transistor is connected to the first inductor, and the control end of the first transistor is used to access a control signal; The first end of the first resistor is connected to the second end of the first transistor, and the second end of the first resistor is connected to the ground end; An input terminal of the first current source is connected to a power supply terminal, and an output terminal of the first current source is connected to a first terminal of the second transistor; The control end of the second transistor is connected to the control end of the third transistor, the first end of the second resistor is connected to the second end of the second transistor, and the second end of the second resistor is connected to the second end of the first transistor; The input end of the second current source is connected to the power supply end, the output end of the second current source is connected to the first end of the third transistor, and the first end of the third transistor is connected to the control end of the third transistor; The first end of the third resistor is connected to the second end of the third transistor, and the second end of the third resistor is connected to the ground end; The second end of the fifth transistor is connected to the power supply end, the control end of the fifth transistor is connected to the first end of the fifth transistor, and the first end of the fifth transistor is connected to the first end of the fourth transistor; The control end of the fourth transistor is connected to the first end of the second transistor, and the second end of the fourth transistor is connected to the second end of the third transistor; The second end of the sixth transistor is connected to the power supply end, the control end of the sixth transistor is connected to the control end of the fifth transistor, and the first end of the sixth transistor is used to output the sensing current.

8. The switching power supply circuit according to claim 7, characterized in that: The current detection calibration module is used to control the size of the first resistor to calibrate the current detection module; and / or The current detection calibration module is used to control the size of the second resistor and the third resistor to calibrate the current detection module; and / or The current detection calibration module is used to control the mirror ratio of the fifth transistor and the sixth transistor to calibrate the current detection module.

9. The switching power supply circuit according to claim 8, characterized in that: The second end of the output transistor is connected to the first end of the first resistor, and the first transistor and the output transistor have the same size.

10. A power supply system, characterized in that: The invention comprises a switching power supply circuit as claimed in any one of claims 1 to 9.

11. An electronic device, characterized in that: Comprising the power supply system as claimed in claim 10.

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