Bimodal DC-DC conversion circuit, switching power supply chip and electronic equipment

Abstract

The invention belongs to the field of electronic circuits, and provides a bimodal DC-DC conversion circuit, a switching power supply chip and electronic equipment. The circuit comprises a first switch module, a second switch module, a third switch module, a fourth switch module, an inductor module and a capacitor module, the first switch module is connected with the inductor module, the capacitor module and the second switch module, and the capacitor module is connected with the third switch module and the fourth switch module. The third switch module is connected with the second switch module, one end of the output capacitor and the load. The fourth switch module is connected with the inductor module, one end of the input capacitor and the power supply. When the boost ratio of the DC-DC conversion circuit is high, the DC-DC conversion circuit works in a first mode to improve the conversion efficiency; and when the boost ratio of the DC-DC conversion circuit is low, the DC-DC conversion circuit is switched to a second mode, namely the control mode of the traditional Boost converter, so as to adapt to the requirement of wide input voltage.

Description

Technical Field

[0001] This application belongs to the field of electronic circuit technology, and in particular relates to a dual-mode DC-DC converter circuit, a switching power supply chip, and an electronic device. Background Technology

[0002] Portable electronic products, such as mobile phones, tablets, laptops, and wearable devices, are widely used in daily life, and batteries are an indispensable component of these products. These electronic products typically use a small number of batteries connected in series: for example, mobile phones, tablets, and wearable devices mostly use a single battery, while laptops generally use three or four batteries connected in series, with a single battery having a rated voltage of 3.7V. The LCDs (Liquid Crystal Displays) in these devices use white LEDs for backlighting. These LEDs are connected in series first and then in parallel, for example, 5 to 11 LEDs connected in series. Their total driving voltage range is approximately 12V to 33V, therefore a boost DC-DC converter is needed to increase the battery voltage. The most widely used boost DC-DC converter is the Boost converter. Generally, at the same power conversion level, the greater the difference between the output voltage and the input voltage, the lower the power conversion efficiency. If the output voltage remains constant, the lower the input voltage, the higher the boost ratio (i.e., the ratio of output voltage to input voltage) of the converter. In this case, the longer the conduction time of the lower transistor in the Boost converter, the longer the inductor charging time, and the larger the inductor current ripple, leading to increased switching losses and inductor hysteresis losses. Furthermore, as the input voltage decreases, the input current (i.e., the average inductor current) increases, resulting in increased conduction losses. Therefore, due to the inherent limitations of the traditional Boost topology, Boost converters suffer from relatively low power conversion efficiency under wide input voltage conditions; that is, the higher the boost ratio, the lower the power conversion efficiency. Summary of the Invention

[0003] This application provides a dual-mode DC-DC converter circuit, a switching power supply chip, and an electronic device, which can solve the problem of low power conversion efficiency of traditional Boost converters under wide input voltage conditions.

[0004] In a first aspect, embodiments of this application provide a dual-mode DC-DC converter circuit, including a first switching module, a second switching module, a third switching module, a fourth switching module, an inductor module, and a capacitor module. The first switching module is connected to the inductor module, the capacitor module, and the second switching module. The capacitor module is connected to the third switching module and the fourth switching module. The third switching module is connected to the second switching module, one end of the output capacitor, and the load. The fourth switching module is connected to the inductor module, one end of the input capacitor, and the power supply. When the input voltage is less than a first preset value, the dual-mode DC-DC converter circuit operates in the first mode; when the input voltage is greater than a second preset value, the dual-mode DC-DC converter circuit switches to the second mode; wherein, the first preset value is less than or equal to the second preset value; In the first mode, the second switch module is controlled to be disconnected; in the first stage, the first switch module and the fourth switch module are controlled to be turned on, and the third switch module is controlled to be disconnected, and the power supply charges the inductor module and the capacitor module respectively; in the second stage, the first switch module and the fourth switch module are controlled to be disconnected, and the third switch module is controlled to be turned on, and the input capacitor, the inductor module and the capacitor module are connected in series to supply power to the load. In the second mode, the third and fourth switch modules are disconnected; in the first stage, the first switch module is turned on and the second switch module is turned off, and the power supply charges the inductor module; in the second stage, the first switch module is turned off and the second switch module is turned on, and the input capacitor and the inductor module are connected in series to supply power to the load; wherein, the first and second stages are performed alternately.

[0005] In one possible implementation of the first aspect, the dual-mode DC-DC converter circuit further includes a control module, a drive module, and a detection module. The control module is connected to the drive module and the detection module, respectively, and the drive module is connected to the first switch module, the second switch module, the third switch module, and the fourth switch module, respectively. The detection module is used to receive the output voltage and the threshold voltage. When the output voltage is greater than the threshold voltage, the output level signal changes from low level to high level; when the output voltage is less than the threshold voltage, the output level signal changes from high level to low level; wherein, the threshold voltage is twice the sum of the input voltage and the deviation voltage. Alternatively, the detection module is used to receive a first driving signal and detect the duty cycle of the first switching module according to the first driving signal; when the duty cycle of the first switching module is greater than a critical value and continues for a preset time, the output level signal changes from low level to high level; when the duty cycle of the first switching module is less than a critical value and continues for a preset time, the output level signal changes from high level to low level. The control module receives a reference voltage, an output voltage, a first current, and a level signal, and outputs a first drive signal, a second drive signal, a third drive signal, and a fourth drive signal to the drive module based on the reference voltage, the output voltage, the first current, and the level signal. This causes the drive module to drive the first switch module according to the first drive signal, the second switch module according to the second drive signal, the third switch module according to the third drive signal, and the fourth switch module according to the fourth drive signal. The first current is obtained by sampling the current flowing through the first switch module. When the level signal changes from low to high, the dual-mode DC-DC converter circuit switches to the first mode; when the level signal changes from high to low, the dual-mode DC-DC converter circuit switches to the second mode.

[0006] In one possible implementation of the first aspect, the detection module includes a first comparator, a first input terminal of the first comparator for receiving an output voltage, a second input terminal of the first comparator for receiving a threshold voltage, and an output terminal of the first comparator connected to the control module.

[0007] In one possible implementation of the first aspect, the control module includes a control unit, a PWM modulation unit, a compensation unit, an error amplification unit, and a transient adjustment unit. The PWM modulation unit is connected to the compensation unit, the error amplification unit, the transient adjustment unit, and the control unit, respectively. The control unit is connected to the transient adjustment unit, the detection module, and the drive module, respectively. The error amplification unit is used to receive the reference voltage and the output voltage, and output a current error signal according to the reference voltage and the output voltage; the compensation unit is used to compensate the current error signal to obtain a voltage error signal; the PWM modulation unit is used to receive the first current and voltage error signals, and output a duty cycle signal according to the first current and the voltage error signals. The control unit receives a duty cycle signal and a level signal, and outputs a first drive signal, a second drive signal, a third drive signal, and a fourth drive signal according to the duty cycle signal and the level signal. When the level signal changes from low to high, the dual-mode DC-DC converter switches to the first mode, and when the level signal changes from high to low, the dual-mode DC-DC converter switches to the second mode. The transient adjustment unit receives the level signal, outputs a pull-down current when the level signal changes from low to high to rapidly reduce the voltage error signal, and outputs a pull-up current when the level signal changes from high to low to rapidly increase the voltage error signal.

[0008] In one possible implementation of the first aspect, the PWM modulation unit includes a second comparator, an adder, an SR flip-flop, a clock generator, and a ramp compensation generator. The first terminal of the adder is used to receive a first current. The second terminal of the adder is connected to the output terminal of the ramp compensation generator. The output terminal of the adder is connected to the first input terminal of the second comparator. The second input terminal of the second comparator is connected to the compensation unit, the transient adjustment unit, and the error amplification unit, respectively. The output terminal of the second comparator is connected to the R terminal of the SR flip-flop. The S terminal of the SR flip-flop is connected to the output terminal of the clock generator and the input terminal of the ramp compensation generator, respectively. The Q terminal of the SR flip-flop is connected to the control unit. The clock generator is used to generate a clock signal; the ramp compensation generator is used to generate a ramp compensation signal according to the clock signal; the adder is used to output a first signal according to the first current and the ramp compensation signal; the second comparator is used to receive a voltage error signal and the first signal, and output a second signal according to the voltage error signal and the first signal; the SR flip-flop is used to output a duty cycle signal according to the second signal and the clock signal.

[0009] In one possible implementation of the first aspect, the compensation unit includes a compensation resistor and a compensation capacitor, the first end of the compensation capacitor is connected to the error amplification unit, the transient adjustment unit and the PWM modulation unit respectively, the second end of the compensation capacitor is connected to the first end of the compensation resistor, and the second end of the compensation resistor is grounded.

[0010] In one possible implementation of the first aspect, the error amplification unit includes an operational amplifier, a first input terminal of which is used to receive a reference voltage, a second input terminal of which is used to receive an output voltage, and an output terminal of which is connected to the compensation unit, the transient adjustment unit, and the PWM modulation unit, respectively.

[0011] In one possible implementation of the first aspect, the transient adjustment unit includes a first monostable pulse subunit, a second monostable pulse subunit, a pull-up current source, a pull-down current source, a pull-up switch, and a pull-down switch. The input terminals of the first monostable pulse subunit and the second monostable pulse subunit are respectively connected to the control unit and the detection module. The output terminal of the first monostable pulse subunit is connected to the control terminal of the pull-up switch. The first conducting terminal of the pull-up switch is connected to the first terminal of the pull-up current source. The second terminal of the pull-up current source receives the power supply voltage. The second conducting terminal of the pull-up switch is connected to the first terminal of the pull-down current source, the compensation unit, the error amplification unit, and the PWM modulation unit. The second terminal of the pull-down current source is connected to the first conducting terminal of the pull-down switch. The second conducting terminal of the pull-down switch is grounded. The control terminal of the pull-down switch is connected to the output terminal of the second monostable pulse subunit.

[0012] Secondly, embodiments of this application provide a switching power supply chip, including the dual-mode DC-DC conversion circuit described in any one of the first aspects.

[0013] Thirdly, embodiments of this application provide an electronic device including the switching power supply chip described in any one of the second aspects.

[0014] The beneficial effects of the embodiments in this application compared with the prior art are: This application provides a dual-mode DC-DC converter circuit, including a first switch module, a second switch module, a third switch module, a fourth switch module, an inductor module, and a capacitor module. The first switch module is connected to the inductor module, the capacitor module, and the second switch module. The capacitor module is connected to the third switch module and the fourth switch module. The third switch module is connected to the second switch module, one end of the output capacitor, and the load. The fourth switch module is connected to the inductor module, one end of the input capacitor, and the power supply.

[0015] When the input voltage is less than the first preset value, it indicates that the boost ratio of the dual-mode DC-DC converter circuit is high. At this time, the dual-mode DC-DC converter circuit operates in the first mode: the second switch module is controlled to be disconnected; in the first stage, the first switch module and the fourth switch module are controlled to be turned on, and the third switch module is controlled to be disconnected, so that the power supply charges the inductor module and the capacitor module respectively; in the second stage, the first switch module and the fourth switch module are controlled to be disconnected, and the third switch module is controlled to be turned on, so that the input capacitor, the inductor module and the capacitor module are connected in series to supply power to the load.

[0016] When the input voltage is greater than the second preset value, the boost ratio of the dual-mode DC-DC converter circuit is low. At this time, the dual-mode DC-DC converter circuit switches to the second mode: the third and fourth switch modules are disconnected. In the first stage, the first switch module is turned on and the second switch module is turned off, and the power supply charges the inductor module. In the second stage, the first switch module is turned off and the second switch module is turned on, and the input capacitor and the inductor module are connected in series to supply power to the load. That is, the second mode is the control mode of the traditional Boost converter. The first and second stages alternate. The first preset value is less than or equal to the second preset value.

[0017] As can be seen from the above, when the boost ratio of the dual-mode DC-DC converter is high, the dual-mode DC-DC converter operates in the first mode. Compared with the traditional Boost converter, this energy transfer method is more efficient, mainly because: 1. When the inductor module releases energy, it is connected in series with the capacitor module. This is equivalent to the series discharge voltage changing from the input voltage to twice the input voltage. The higher the discharge voltage, the higher the energy transfer efficiency.

[0018] 2. Theoretical analysis shows that the duty cycle of the dual-mode DC-DC converter circuit in the first mode is... Where VOUT represents the output voltage and VIN represents the input voltage; while the duty cycle of a traditional Boost converter As can be seen from the expression, D1 is significantly lower than D2. In this application, the discharge time of the inductor module is (1-D1)Ts, while in a traditional Boost converter, the discharge time of the inductor is (1-D2)Ts. Under the same switching frequency (1 / Ts), where Ts represents the switching period, the discharge time of the inductor module in this application is extended, that is, the energy conversion time is extended, thereby improving the conversion efficiency.

[0019] 3. Theoretical analysis shows that, compared with the traditional Boost converter, due to the reduced duty cycle, the charging time of the inductor module is shortened, the current ripple flowing through the inductor module is reduced, and the corresponding hysteresis loss of the inductor module is reduced. The root mean square current decreases as the AC ripple decreases, and the conduction loss also decreases accordingly.

[0020] When the boost ratio of the dual-mode DC-DC converter is low, the dual-mode DC-DC converter switches to the second mode, that is, it operates in the control mode of the traditional Boost converter, thereby solving the problem of low power conversion efficiency of the traditional Boost converter under wide input voltage conditions.

[0021] It is understood that the beneficial effects of the second and third aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0023] Figure 1 This is a schematic diagram of a dual-mode DC-DC converter circuit provided in an embodiment of this application; Figure 2 This is a schematic diagram of a dual-mode DC-DC converter circuit provided in another embodiment of this application; Figure 3 This is a schematic diagram of a dual-mode DC-DC converter circuit provided in another embodiment of this application; Figure 4 This is a waveform diagram of the dual-mode DC-DC converter circuit of this application operating in the first mode; Figure 5 This is a waveform diagram of the dual-mode DC-DC converter circuit of this application operating in the second mode; Figure 6 This is a schematic diagram of a dual-mode DC-DC converter circuit provided in another embodiment of this application; Figure 7 This is a circuit connection diagram of a dual-mode DC-DC converter circuit provided in an embodiment of this application; Figure 8 This is a circuit connection diagram of a dual-mode DC-DC converter circuit provided in another embodiment of this application.

[0024] In the diagram: 11. First switch module; 12. Second switch module; 13. Third switch module; 14. Fourth switch module; 15. Inductor module; 16. Capacitor module; 17. Control module; 171. Control unit; 172. PWM modulation unit; 173. Compensation unit; 174. Error amplification unit; 175. Transient adjustment unit; 18. Drive module; 19. Detection module; 20. Power supply; 21. Load. Detailed Implementation

[0025] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0026] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0027] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0029] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0031] To address the issue of low power conversion efficiency in traditional Boost converters under wide input voltage conditions, this application provides a dual-mode DC-DC converter circuit. When the boost ratio of the dual-mode DC-DC converter circuit is high, it operates in the first mode to improve conversion efficiency. When the boost ratio of the dual-mode DC-DC converter circuit is low, it switches to the second mode, i.e., the control mode of the traditional Boost converter, to adapt to the requirements of wide input voltage, thereby solving the problem of low power conversion efficiency in traditional Boost converters under wide input voltage conditions.

[0032] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0033] Figure 1 A schematic diagram of a dual-mode DC-DC converter circuit provided in an embodiment of this application is shown. Figure 1 As shown, the dual-mode DC-DC converter circuit includes a first switching module 11, a second switching module 12, a third switching module 13, a fourth switching module 14, an inductor module 15, and a capacitor module 16. The first switching module 11 is connected to the inductor module 15, the capacitor module 16, and the second switching module 12. The capacitor module 16 is connected to the third switching module 13 and the fourth switching module 14. The third switching module 13 is connected to the second switching module 12, one end of the output capacitor Cout, and the load 21. The fourth switching module 14 is connected to the inductor module 15, one end of the input capacitor Cin, and the power supply 20. The power supply 20 provides the input voltage VIN.

[0034] Specifically, when the input voltage VIN is less than the first preset value, it indicates that the boost ratio of the dual-mode DC-DC converter circuit is high. At this time, the dual-mode DC-DC converter circuit operates in the first mode: the second switch module 12 is turned off; in the first stage, the first switch module 11 and the fourth switch module 14 are turned on, and the third switch module 13 is turned off. The power supply 20 charges the inductor module 15 and the capacitor module 16 respectively. In the second stage, the first switch module 11 and the fourth switch module 14 are turned off, and the third switch module 13 is turned on. The input capacitor Cin, the inductor module 15 and the capacitor module 16 are connected in series to supply power to the load 21.

[0035] When the input voltage VIN is greater than the second preset value, it indicates that the boost ratio of the dual-mode DC-DC converter circuit is low. At this time, the dual-mode DC-DC converter circuit switches to the second mode: the third switch module 13 and the fourth switch module 14 are disconnected. In the first stage, the first switch module 11 is turned on and the second switch module 12 is turned off, and the power supply 20 charges the inductor module 15. In the second stage, the first switch module 11 is turned off and the second switch module 12 is turned on, and the input capacitor Cin and the inductor module 15 are connected in series to supply power to the load 21. That is, the second mode is the control mode of the traditional Boost converter. The first and second stages alternate. The first preset value is less than or equal to the second preset value. It should be noted that the first preset value is used to determine whether the input voltage decreases, and its specific value is not fixed and can be flexibly adjusted according to the actual application requirements. Similarly, the second preset value is used to determine whether the input voltage increases, and its specific value is also not fixed and can be adapted and adjusted according to the actual application.

[0036] As can be seen from the above, when the boost ratio of the dual-mode DC-DC converter is high, the dual-mode DC-DC converter operates in the first mode. Compared with the traditional Boost converter, this energy transfer method is more efficient, mainly because: 1. When the inductor module 15 releases energy, it is connected in series with the capacitor module 16. This is equivalent to the series discharge voltage changing from the input voltage VIN to twice the input voltage VIN. The higher the discharge voltage, the higher the energy transfer efficiency.

[0037] 2. Theoretical analysis shows that the duty cycle of the dual-mode DC-DC converter circuit in the first mode is... Where VOUT represents the output voltage and VIN represents the input voltage; while the duty cycle of a traditional Boost converter As can be seen from the expression, D1 is significantly lower than D2. In this application, the discharge time of the inductor module 15 is (1-D1)Ts, while the discharge time of the inductor in a conventional Boost converter is (1-D2)Ts. Under the same switching frequency (1 / Ts), where Ts represents the switching period, the discharge time of the inductor module 15 in this application is extended, that is, the energy conversion time is extended, thereby improving the conversion efficiency.

[0038] 3. Theoretical analysis shows that, compared with the traditional Boost converter, due to the reduced duty cycle, the charging time of the inductor module 15 is shortened, the current ripple flowing through the inductor module 15 is reduced, and the hysteresis loss of the inductor module 15 is reduced accordingly. The root mean square current decreases as the AC ripple decreases, and the conduction loss also decreases.

[0039] When the boost ratio of the dual-mode DC-DC converter is low, the dual-mode DC-DC converter switches to the second mode, that is, the control mode of the traditional Boost converter. This application switches modes according to the change of the boost ratio, thereby solving the problem of low power conversion efficiency of the traditional Boost converter under wide input voltage conditions.

[0040] In one embodiment of this application, such as Figure 2 As shown, the dual-mode DC-DC converter circuit also includes a control module 17, a drive module 18, and a detection module 19. The control module 17 is connected to the drive module 18 and the detection module 19, respectively. The drive module 18 is connected to the first switch module 11, the second switch module 12, the third switch module 13, and the fourth switch module 14, respectively.

[0041] Specifically, such as Figure 2 As shown, the detection module 19 is used to receive the output voltage VOUT and the threshold voltage Vth, wherein the threshold voltage Vth is twice the input voltage VIN and the deviation voltage V. HRThe sum of the voltages; when the output voltage VOUT is greater than the threshold voltage Vth, the output level signal M changes from low to high, indicating that the dual-mode DC-DC converter circuit switches to the first mode; when the output voltage VOUT is less than the threshold voltage Vth, the output level signal M changes from high to low, indicating that the dual-mode DC-DC converter circuit switches to the second mode. It should be noted that adjusting the deviation voltage V... HR The value can adjust the switching point between the two modes.

[0042] Or, such as Figure 3 As shown, the detection module 19 receives the first driving signal driver1 and detects the duty cycle of the first switching module 11 based on the first driving signal driver1. When the duty cycle of the first switching module 11 is greater than a threshold value and remains so for a preset time, the output level signal M changes from low to high, indicating that the dual-mode DC-DC converter circuit switches to the first mode. When the duty cycle of the first switching module 11 is less than the threshold value and remains so for a preset time, the output level signal M changes from high to low, indicating that the dual-mode DC-DC converter circuit switches to the second mode. The input voltage VIN changes inversely to the duty cycle of the first switching module 11: when the input voltage VIN increases, the duty cycle of the first switching module 11 decreases; when the input voltage VIN decreases, the duty cycle of the first switching module 11 increases.

[0043] It should be noted that adjusting the threshold value can adjust the switching point between the two modes; in order to prevent potential oscillations near the switching point, the duty cycle detection should avoid dynamic interference from the load or input / output.

[0044] The control module 17 receives the reference voltage VREF, the output voltage VOUT, the first current i1, and the level signal M. Based on these parameters, it outputs a first drive signal driver1, a second drive signal driver2, a third drive signal driver3, and a fourth drive signal driver4. This causes the drive module 18 to drive the first switch module 11 according to the first drive signal driver1, the second switch module 12 according to the second drive signal driver2, the third switch module 13 according to the third drive signal driver3, and the fourth switch module 14 according to the fourth drive signal driver4. The first current i1 is the current obtained by sampling the current flowing through the first switch module 11.

[0045] When the level signal M changes from low to high, the dual-mode DC-DC converter circuit switches to the first mode; when the level signal M changes from high to low, the dual-mode DC-DC converter circuit switches to the second mode.

[0046] This application first detects the change in boost ratio of the dual-mode DC-DC converter circuit through the detection module 19 and outputs a level signal M. Then, the control module 17 outputs a drive signal to drive the drive module 18 to drive each switch module to work in the corresponding mode.

[0047] In one embodiment of this application, such as Figure 2 As shown, the first switching module 11 includes a first switching transistor Q1. The gate of the first switching transistor Q1 is connected to the driving module 18, the source of the first switching transistor Q1 is grounded, and the drain of the first switching transistor Q1 is connected to the second switching module 12, the inductor module 15 and the capacitor module 16 respectively.

[0048] like Figure 2 As shown, the second switching module 12 includes a second switching transistor Q2. The gate of the second switching transistor Q2 is connected to the driving module 18. The source of the second switching transistor Q2 is connected to the drain of the first switching transistor Q1, the inductor module 15 and the capacitor module 16 respectively. The drain of the second switching transistor Q2 is connected to the third switching module 13, one end of the output capacitor Cout and the load 21 respectively.

[0049] like Figure 2 As shown, the third switch module 13 includes a third switch transistor Q3. The gate of the third switch transistor Q3 is connected to the drive module 18. The source of the third switch transistor Q3 is connected to the capacitor module 16 and the fourth switch module 14 respectively. The drain of the third switch transistor Q3 is connected to the drain of the second switch transistor Q2, one end of the output capacitor Cout, and the load 21 respectively.

[0050] like Figure 2 As shown, the fourth switch module 14 includes a fourth switch transistor SW1. The control terminal of the fourth switch transistor SW1 is connected to the drive module 18. The first conducting terminal of the fourth switch transistor SW1 is connected to the power supply 20, one end of the input capacitor Cin, and the inductor module 15, respectively. The second conducting terminal of the fourth switch transistor SW1 is connected to the source of the third switch transistor Q3 and the capacitor module 16, respectively.

[0051] like Figure 2 As shown, the inductor module 15 includes an inductor L1. The first end of the inductor L1 is connected to the drain of the first switch Q1, the source of the second switch Q2, and the capacitor module 16, respectively. The second end of the inductor L1 is connected to the first conducting end of the fourth switch SW1, the power supply 20, and one end of the input capacitor Cin, respectively.

[0052] like Figure 2 As shown, the capacitor module 16 includes a capacitor C1. The first end of the capacitor C1 is connected to the first end of the inductor L1, the drain of the first switch Q1, and the source of the second switch Q2. The second end of the capacitor C1 is connected to the second conducting end of the fourth switch SW1 and the source of the third switch Q3.

[0053] Specifically, in combination Figure 2 and Figure 4 The first mode will be explained. Figure 4 In the diagram, T1 corresponds to the first stage, T2 corresponds to the second stage, and i L1 This represents the inductor current. Assuming the circuit has reached steady state, inductor L1 operates in continuous current mode. C1 This represents the capacitor current.

[0054] In the first mode, the second switch Q2 is always off (i.e., the second drive signal driver2 is always low) and does not participate in the operation; the first switch Q1 is the main switch; the drive signal of the third switch Q3 (i.e., the third drive signal driver3) is opposite to the drive signal of the first switch Q1 (i.e., the first drive signal driver1); the drive signal of the fourth switch SW1 (i.e., the fourth drive signal driver4) is the same as the drive signal of the first switch Q1 (i.e., the first drive signal driver1).

[0055] When the first switch Q1 is turned on, i.e., at the start of stage T1, the inductor L1 is charged by the input voltage VIN, and the inductor current i L1 The voltage rises; during stage T1, the third switch Q3 is in the off state. At the same time as the first switch Q1 turns on, the fourth switch SW1 also turns on, and capacitor C1 is charged. The voltage of capacitor C1 is charged to the same voltage as the input capacitor Cin at the end of T1, that is, the input voltage VIN.

[0056] In the next stage, at the start of T2, the first switch Q1 is turned off, and the fourth switch SW1 is also turned off. Inductor L1, input capacitor Cin, and capacitor C1 are connected in series and discharge the output voltage Cout through the body diode of the third switch Q3. After the dead time, the third switch Q3 turns on and reduces the voltage drop. The function of the third switch Q3 is a synchronous rectifier, which can be replaced by a rectifier diode. Through the discharge of inductor L1, the energy of the input voltage VIN and capacitor C1 is transferred to the output terminal, and at the same time, inductor L1 releases the stored magnetic energy to the output terminal. Compared with traditional Boost converters, this energy transfer method is more efficient, mainly because: 1. When inductor L1 releases energy, it is connected in series with capacitor C1. This is equivalent to the series discharge voltage changing from the input voltage VIN to twice the input voltage VIN. The higher the discharge voltage, the higher the energy transfer efficiency.

[0057] 2. Theoretical analysis shows that the duty cycle of the dual-mode DC-DC converter circuit in the first mode is... Where VOUT represents the output voltage and VIN represents the input voltage; while the duty cycle of a traditional Boost converter As can be seen from the expression, D1 is significantly lower than D2. In this application, the discharge time of inductor L1 is (1-D1)Ts, while in a traditional Boost converter, the discharge time of the inductor is (1-D2)Ts. Under the same switching frequency (1 / Ts), where Ts represents the switching period, the discharge time of inductor L1 in this application is extended, that is, the energy conversion time is extended, thereby improving the conversion efficiency.

[0058] 3. Theoretical analysis shows that, compared with the traditional Boost converter, due to the reduced duty cycle, the charging time of inductor L1 is shortened, the inductor current ripple is reduced, and the corresponding hysteresis loss of inductor L1 is reduced. The root mean square current decreases as the AC ripple decreases, and the conduction loss also decreases accordingly.

[0059] Combination Figure 2 and Figure 5 The second mode will be explained. Figure 5 In the diagram, T1 corresponds to the first stage, T2 corresponds to the second stage, and i L1 This represents the inductor current. Assuming the circuit has reached steady state, inductor L1 operates in continuous current mode. C1 This represents the capacitor current.

[0060] In the second mode, the third switch Q3 and the fourth switch SW1 are always in the off state (i.e., the third drive signal driver3 and the fourth drive signal driver4 are always at a low level) and do not participate in the operation; the first switch Q1 and the second switch Q2 operate in a complementary state, and the drive signal of the first switch Q1 (i.e., the first drive signal driver1) is opposite to the drive signal of the second switch Q2 (i.e., the second drive signal driver2); the first switch Q1 is the main switch, and the second switch Q2 is a synchronous rectifier, which can be replaced by a rectifier diode.

[0061] When the first switch Q1 is turned on, that is, at the beginning of T1, the inductor L1 is charged by the input voltage VIN, and the inductor current i L1 During the T1 stage, the second switch Q2 is in the off state.

[0062] In the next stage, at the start of T2, the first switch Q1 is turned off. Inductor L1 and input capacitor Cin are connected in series and discharge through the body diode of the second switch Q2 to output capacitor Cout. After the dead time, the second switch Q2 turns on and reduces the voltage drop. The second switch Q2 can be replaced by a rectifier diode. Through the discharge via inductor L1, the energy of the input voltage VIN is transferred to the output terminal, and simultaneously, the inductor L1 releases the stored magnetic energy to the output terminal.

[0063] It should be noted that the above-mentioned switching devices can be directly replaced by different types of switching devices, or two switching devices can be connected in series, or one switching device can be connected in series with one diode, or one diode can be used as a replacement.

[0064] In one embodiment of this application, such as Figure 6 As shown, the control module 17 includes a control unit 171, a PWM modulation unit 172, a compensation unit 173, an error amplification unit 174, and a transient adjustment unit 175. The PWM modulation unit 172 is connected to the compensation unit 173, the error amplification unit 174, the transient adjustment unit 175, and the control unit 171, respectively. The control unit 171 is connected to the transient adjustment unit 175, the detection module 19, and the drive module 18, respectively.

[0065] Specifically, the error amplification unit 174 receives the reference voltage VREF and the output voltage VOUT, and outputs a current error signal Icomp based on the reference voltage VREF and the output voltage VOUT. The compensation unit 173 compensates for the current error signal Icomp to obtain the voltage error signal Vcomp. The PWM modulation unit 172 receives the first current i1 and the voltage error signal Vcomp, and outputs a duty cycle signal Duty based on the first current i1 and the voltage error signal Vcomp.

[0066] The control unit 171 receives the duty cycle signal Duty and the level signal M, and outputs a first drive signal driver1, a second drive signal driver2, a third drive signal driver3, and a fourth drive signal driver4 according to the duty cycle signal Duty and the level signal M. When the level signal M changes from low to high, the dual-mode DC-DC converter circuit switches to the first mode; when the level signal M changes from high to low, the dual-mode DC-DC converter circuit switches to the second mode.

[0067] The transient adjustment unit 175 receives the level signal M. When the level signal M changes from low to high, it indicates that the dual-mode DC-DC converter circuit has switched to the first mode. At this time, a pull-down current is output to quickly reduce the voltage error signal Vcomp, preventing the output voltage VOUT and inductor current i from increasing during mode switching. L1 Overshoot occurs; when the level signal M changes from high level to low level, it indicates that the dual-mode DC-DC converter circuit has switched to the second mode. At this time, the output pull-up current is used to make the voltage error signal Vcomp rise quickly, so as to prevent the output voltage VOUT from dropping too much during the mode switching and to ensure that the switching process is fast and smooth.

[0068] In one embodiment of this application, such as Figure 7As shown, the PWM modulation unit 172 includes a second comparator Comp2, an adder, an SR flip-flop SRFF, a clock generator OSC, and a ramp compensation generator SC. The first terminal of the adder is used to receive a first current i1. The second terminal of the adder is connected to the output terminal of the ramp compensation generator SC. The output terminal of the adder is connected to the first input terminal of the second comparator Comp2. The second input terminal of the second comparator Comp2 is connected to the compensation unit 173, the transient adjustment unit 175, and the error amplification unit 174, respectively. The output terminal of the second comparator Comp2 is connected to the R terminal of the SR flip-flop SRFF. The S terminal of the SR flip-flop SRFF is connected to the output terminal of the clock generator OSC and the input terminal of the ramp compensation generator SC, respectively. The Q terminal of the SR flip-flop SRFF is connected to the control unit 171. In this embodiment, the first input terminal of the second comparator Comp2 is a non-inverting input terminal, and the second input terminal of the second comparator Comp2 is an inverting input terminal.

[0069] Specifically, the clock generator OSC generates the clock signal CLK. The slope compensation generator SC generates a slope compensation signal based on the clock signal CLK. The adder outputs a first signal V based on the first current i1 and the slope compensation signal. s1 The second comparator Comp2 is used to receive the voltage error signal Vcomp and the first signal V. s1 And based on the voltage error signal Vcomp and the first signal V s1 Output the second signal V s2 The SR trigger SRFF is used based on the second signal V. s2 The clock signal CLK outputs the duty cycle signal Duty.

[0070] In one embodiment of this application, such as Figure 7 As shown, the error amplification unit 174 includes an operational amplifier EA. The first input terminal of the operational amplifier EA is used to receive the reference voltage VREF, and the second input terminal of the operational amplifier EA is used to receive the output voltage VOUT. The output terminal of the operational amplifier EA is connected to the compensation unit 173, the transient adjustment unit 175, and the PWM modulation unit 172, respectively. In this embodiment, the first input terminal of the operational amplifier EA is a non-inverting input terminal, and the second input terminal of the operational amplifier EA is an inverting input terminal.

[0071] Specifically, the operational amplifier EA is used to implement the voltage regulation function, and outputs the current error signal Icomp based on the reference voltage VREF and the output voltage VOUT.

[0072] In one embodiment of this application, such as Figure 7As shown, the compensation unit 173 includes a compensation resistor Rc and a compensation capacitor Cc. The first end of the compensation capacitor Cc is connected to the error amplification unit 174, the transient adjustment unit 175 and the PWM modulation unit 172 respectively. The second end of the compensation capacitor Cc is connected to the first end of the compensation resistor Rc, and the second end of the compensation resistor Rc is grounded.

[0073] Specifically, the current error signal Icomp generated by the operational amplifier EA is transformed into the voltage error signal Vcomp after passing through the compensation network composed of the compensation resistor Rc and the compensation capacitor Cc.

[0074] In one embodiment of this application, such as Figure 7 As shown, the transient adjustment unit 175 includes a first monostable pulse subunit OS1, a second monostable pulse subunit OS2, and a pull-up current source I. PU Pull-down current source I PD Pull-up switches SW2 and SW3, the input terminals of the first monostable pulse subunit OS1 and the second monostable pulse subunit OS2 are respectively connected to the control unit 171 and the detection module 19. The output terminal of the first monostable pulse subunit OS1 is connected to the control terminal of the pull-up switch SW2. The first conducting terminal of the pull-up switch SW2 is connected to the pull-up current source I. PU The first terminal is connected to the pull-up current source I. PU The second terminal receives the power supply voltage, and the second conducting terminal of the pull-up switch SW2 is connected to the pull-down current source I. PD The first terminal, compensation unit 173, error amplification unit 174, and PWM modulation unit 172 are connected, and pull-down current source I is connected. PD The second terminal is connected to the first conducting terminal of the pull-down switch SW3, the second conducting terminal of the pull-down switch SW3 is grounded, and the control terminal of the pull-down switch SW3 is connected to the output terminal of the second monostable pulse subunit OS2.

[0075] Specifically, when the level signal M output by the detection module 19 changes from low to high, it indicates that the dual-mode DC-DC converter circuit has switched to the first mode; the rising edge of the level signal M triggers the second monostable pulse subunit OS2 to output a timing pulse signal, which controls the pull-down switch SW3 to turn on, causing the pull-down current source I to... PD By connecting to ground, the voltage error signal Vcomp is discharged to ground, thereby rapidly reducing the voltage error signal Vcomp and preventing the output voltage VOUT and inductor current i from fluctuating during mode switching. L1 Overshoot occurs.

[0076] When the level signal M output by the detection module 19 changes from high to low, it indicates that the dual-mode DC-DC converter circuit has switched to the second mode. The falling edge of the level signal M triggers the first monostable pulse subunit OS1 to output a timing pulse signal. This pulse signal controls the pull-up switch SW2 to turn on, causing the pull-up current source I to... PU It is connected to the power supply voltage to charge the voltage error signal Vcomp, thereby causing the voltage error signal Vcomp to rise rapidly, preventing the output voltage VOUT from dropping too much during mode switching, and ensuring that the switching process is fast and stable.

[0077] In one embodiment of this application, such as Figure 7 As shown, the detection module 19 includes a first comparator Comp1. The first input terminal of the first comparator Comp1 is used to receive the output voltage VOUT, the second input terminal of the first comparator Comp1 is used to receive the threshold voltage Vth, and the output terminal of the first comparator Comp1 is connected to the control module 17. In this embodiment, the first input terminal of the first comparator Comp1 is a non-inverting input terminal, and the second input terminal of the first comparator Comp1 is an inverting input terminal.

[0078] Specifically, assuming the dual-mode DC-DC converter circuit operates in the second mode, the first comparator Comp1 compares the output voltage VOUT with the threshold voltage Vth. When the output voltage VOUT is greater than the threshold voltage Vth, the output level signal M changes from low to high. The control unit 171 switches from the second mode to the first mode based on the level signal M, i.e., the second switch Q2 exits the operating mode, and the third switch Q3 and the fourth switch SW1 enter the operating mode. At the moment of mode switching, since the steady-state duty cycles corresponding to the first mode and the second mode are different, the closed-loop control needs to adjust the duty cycle signal Duty: the rising edge of the level signal M triggers the second monostable pulse subunit OS2 to output a timing pulse signal. This pulse signal controls the pull-down switch SW3 to turn on, causing the pull-down current source I... PD By connecting to ground, the voltage error signal Vcomp is discharged to ground, thereby rapidly reducing the voltage error signal Vcomp and the corresponding duty cycle, preventing excessive output voltage VOUT and inductor current i when switching from the second mode to the first mode. L1 Overshoot occurs.

[0079] Similarly, assuming the dual-mode DC-DC converter circuit operates in the first mode, the first comparator Comp1 compares the output voltage VOUT with the threshold voltage Vth. When the output voltage VOUT is less than the threshold voltage Vth, the output level signal M changes from high to low. The control unit 171 switches from the first mode to the second mode based on the level signal M, that is, the third switch Q3 and the fourth switch SW1 exit the operating mode, and the second switch Q2 enters the operating mode. To prevent the output voltage VOUT from overshooting at the moment of switching, the duty cycle signal Duty needs to be adjusted: the falling edge of the level signal M triggers the first monostable pulse subunit OS1 to output a timing pulse signal. This pulse signal controls the pull-up switch SW2 to turn on, causing the pull-up current source I... PU It is connected to the power supply voltage to charge the voltage error signal Vcomp, thereby causing the voltage error signal Vcomp to rise rapidly. The corresponding duty cycle increases rapidly, preventing the output voltage VOUT from dropping too much during mode switching and ensuring a fast and smooth switching process.

[0080] It should be noted that the first comparator Comp1 can be designed as a hysteresis voltage comparator to prevent potential oscillations near the switching point.

[0081] In one embodiment of this application, such as Figure 8 As shown, assuming the dual-mode DC-DC converter circuit operates in the first mode, the detection module 19 detects the duty cycle of the first switch Q1 according to the first drive signal driver1. As the input voltage VIN increases, the duty cycle of the first switch Q1 gradually decreases. When the duty cycle of the first switch Q1 is less than the critical value and remains so for a preset time, the output level signal M changes from high level to low level. The control unit 171 switches from the first mode to the second mode according to the level signal M, that is, the third switch Q3 and the fourth switch SW1 exit the working mode, and the second switch Q2 enters the working mode. To prevent the output voltage VOUT from overshooting at the moment of switching, the duty cycle signal Duty needs to be adjusted: the falling edge of the level signal M triggers the first monostable pulse subunit OS1 to output a timing pulse signal. This pulse signal controls the pull-up switch SW2 to turn on, so that the pull-up current source I... PU It is connected to the power supply voltage to charge the voltage error signal Vcomp, thereby causing the voltage error signal Vcomp to rise rapidly. The corresponding duty cycle increases rapidly, preventing the output voltage VOUT from dropping too much during mode switching and ensuring a fast and smooth switching process.

[0082] Similarly, assuming the dual-mode DC-DC converter circuit operates in the second mode, the detection module 19 detects the duty cycle of the first switch Q1 according to the first drive signal driver1. As the input voltage VIN decreases, the duty cycle of the first switch Q1 gradually increases. When the duty cycle of the first switch Q1 is greater than the critical value and maintained for a preset time, the output level signal M changes from low level to high level. The control unit 171 switches from the second mode to the first mode according to the level signal M, that is, the second switch Q2 exits the working mode, and the third switch Q3 and the fourth switch SW1 enter the working mode. At the moment of mode switching, since the steady-state duty cycles corresponding to the first mode and the second mode are different, the closed-loop control needs to adjust the duty cycle signal Duty: the rising edge of the level signal M will trigger the second monostable pulse subunit OS2 to output a timing pulse signal. This pulse signal controls the pull-down switch SW3 to conduct, so that the pull-down current source I... PD By connecting to ground, the voltage error signal Vcomp is discharged to ground, thereby rapidly reducing the voltage error signal Vcomp and the corresponding duty cycle, preventing excessive output voltage VOUT and inductor current i when switching from the second mode to the first mode. L1 Overshoot occurs.

[0083] In summary, the dual-mode DC-DC converter circuit provided in this application can achieve a wide boost ratio, with its voltage boost factor capable of stable operation within a wide range from 1 to 17 times. Furthermore, under high boost factor conditions, through control mode switching, simulation verification shows that efficiency can be improved by more than 4%. This application is applicable to backlight boost conversion scenarios in laptops, mobile phones, and tablets.

[0084] This application also provides a switching power supply chip, including the dual-mode DC-DC converter circuit described above. Since the switching power supply chip provided in this application adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated upon further here.

[0085] This application also provides an electronic device, including the switching power supply chip described above. Since the electronic device provided in this application adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated upon further here.

[0086] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0087] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A dual-mode DC-DC converter circuit, characterized in that, The device includes a first switch module, a second switch module, a third switch module, a fourth switch module, an inductor module, and a capacitor module. The first switch module is connected to the inductor module, the capacitor module, and the second switch module. The capacitor module is connected to the third switch module and the fourth switch module. The third switch module is connected to the second switch module, one end of the output capacitor, and the load. The fourth switch module is connected to the inductor module, one end of the input capacitor, and the power supply. When the input voltage is less than a first preset value, the dual-mode DC-DC converter circuit operates in the first mode; when the input voltage is greater than a second preset value, the dual-mode DC-DC converter circuit switches to the second mode; wherein, the first preset value is less than or equal to the second preset value; In the first mode, the second switch module is controlled to be disconnected; in the first stage, the first switch module and the fourth switch module are controlled to be turned on, and the third switch module is controlled to be disconnected, and the power supply charges the inductor module and the capacitor module respectively; in the second stage, the first switch module and the fourth switch module are controlled to be disconnected, and the third switch module is controlled to be turned on, and the input capacitor, the inductor module and the capacitor module are connected in series to supply power to the load. In the second mode, the third and fourth switch modules are disconnected; in the first stage, the first switch module is turned on and the second switch module is turned off, and the power supply charges the inductor module; in the second stage, the first switch module is turned off and the second switch module is turned on, and the input capacitor and the inductor module are connected in series to supply power to the load; wherein, the first and second stages are performed alternately.

2. The dual-mode DC-DC converter circuit according to claim 1, characterized in that, The dual-mode DC-DC converter circuit further includes a control module, a drive module, and a detection module. The control module is connected to the drive module and the detection module, respectively. The drive module is connected to the first switch module, the second switch module, the third switch module, and the fourth switch module, respectively. The detection module is used to receive the output voltage and the threshold voltage. When the output voltage is greater than the threshold voltage, the output level signal changes from low level to high level; when the output voltage is less than the threshold voltage, the output level signal changes from high level to low level; wherein, the threshold voltage is twice the sum of the input voltage and the deviation voltage. Alternatively, the detection module is used to receive a first driving signal and detect the duty cycle of the first switching module according to the first driving signal; when the duty cycle of the first switching module is greater than a critical value and continues for a preset time, the output level signal changes from low level to high level; when the duty cycle of the first switching module is less than a critical value and continues for a preset time, the output level signal changes from high level to low level. The control module receives a reference voltage, an output voltage, a first current, and a level signal, and outputs a first drive signal, a second drive signal, a third drive signal, and a fourth drive signal to the drive module based on the reference voltage, the output voltage, the first current, and the level signal. This causes the drive module to drive the first switch module according to the first drive signal, the second switch module according to the second drive signal, the third switch module according to the third drive signal, and the fourth switch module according to the fourth drive signal. The first current is obtained by sampling the current flowing through the first switch module. When the level signal changes from low to high, the dual-mode DC-DC converter circuit switches to the first mode; when the level signal changes from high to low, the dual-mode DC-DC converter circuit switches to the second mode.

3. The dual-mode DC-DC converter circuit according to claim 2, characterized in that, The detection module includes a first comparator, a first input terminal of which is used to receive an output voltage, a second input terminal of which is used to receive a threshold voltage, and an output terminal of which is connected to the control module.

4. The dual-mode DC-DC converter circuit according to claim 2, characterized in that, The control module includes a control unit, a PWM modulation unit, a compensation unit, an error amplification unit, and a transient adjustment unit. The PWM modulation unit is connected to the compensation unit, the error amplification unit, the transient adjustment unit, and the control unit. The control unit is connected to the transient adjustment unit, the detection module, and the drive module. The error amplification unit is used to receive the reference voltage and the output voltage, and output a current error signal according to the reference voltage and the output voltage; the compensation unit is used to compensate the current error signal to obtain a voltage error signal. The PWM modulation unit is used to receive the first current and voltage error signals, and output the duty cycle signal according to the first current and the voltage error signals; The control unit is used to receive a duty cycle signal and a level signal, and output a first drive signal, a second drive signal, a third drive signal and a fourth drive signal according to the duty cycle signal and the level signal; When the voltage level signal changes from low to high, the dual-mode DC-DC converter circuit switches to the first mode; when the voltage level signal changes from high to low, the dual-mode DC-DC converter circuit switches to the second mode. The transient adjustment unit receives the voltage level signal; when the voltage level signal changes from low to high, it outputs a pull-down current to rapidly reduce the voltage error signal; when the voltage level signal changes from high to low, it outputs a pull-up current to rapidly increase the voltage error signal.

5. The dual-mode DC-DC converter circuit according to claim 4, characterized in that, The PWM modulation unit includes a second comparator, an adder, an SR flip-flop, a clock generator, and a ramp compensation generator. The first terminal of the adder is used to receive a first current. The second terminal of the adder is connected to the output terminal of the ramp compensation generator. The output terminal of the adder is connected to the first input terminal of the second comparator. The second input terminal of the second comparator is connected to the compensation unit, the transient adjustment unit, and the error amplification unit, respectively. The output terminal of the second comparator is connected to the R terminal of the SR flip-flop. The S terminal of the SR flip-flop is connected to the output terminal of the clock generator and the input terminal of the ramp compensation generator, respectively. The Q terminal of the SR flip-flop is connected to the control unit. The clock generator is used to generate a clock signal; the ramp compensation generator is used to generate a ramp compensation signal according to the clock signal; the adder is used to output a first signal according to the first current and the ramp compensation signal; the second comparator is used to receive a voltage error signal and the first signal, and output a second signal according to the voltage error signal and the first signal; the SR flip-flop is used to output a duty cycle signal according to the second signal and the clock signal.

6. The dual-mode DC-DC converter circuit according to claim 4, characterized in that, The compensation unit includes a compensation resistor and a compensation capacitor. The first end of the compensation capacitor is connected to the error amplification unit, the transient adjustment unit and the PWM modulation unit respectively. The second end of the compensation capacitor is connected to the first end of the compensation resistor, and the second end of the compensation resistor is grounded.

7. The dual-mode DC-DC converter circuit according to claim 4, characterized in that, The error amplification unit includes an operational amplifier. The first input terminal of the operational amplifier is used to receive a reference voltage, the second input terminal of the operational amplifier is used to receive an output voltage, and the output terminal of the operational amplifier is connected to the compensation unit, the transient adjustment unit, and the PWM modulation unit, respectively.

8. The dual-mode DC-DC converter circuit according to claim 4, characterized in that, The transient adjustment unit includes a first monostable pulse subunit, a second monostable pulse subunit, a pull-up current source, a pull-down current source, a pull-up switch, and a pull-down switch. The input terminals of the first and second monostable pulse subunits are respectively connected to the control unit and the detection module. The output terminal of the first monostable pulse subunit is connected to the control terminal of the pull-up switch. The first conducting terminal of the pull-up switch is connected to the first terminal of the pull-up current source. The second terminal of the pull-up current source receives the power supply voltage. The second conducting terminal of the pull-up switch is connected to the first terminal of the pull-down current source, the compensation unit, the error amplification unit, and the PWM modulation unit. The second terminal of the pull-down current source is connected to the first conducting terminal of the pull-down switch. The second conducting terminal of the pull-down switch is grounded. The control terminal of the pull-down switch is connected to the output terminal of the second monostable pulse subunit.

9. A switching power supply chip, characterized in that, Includes the dual-mode DC-DC converter circuit as described in any one of claims 1-8.

10. An electronic device, characterized in that, Includes the electronic device as described in claim 9.

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