Switching power supply device, method for controlling pulse width and electronic equipment
By detecting the amplitude of the analog signal and controlling the frequency of the driving pulse, the problem of noise pollution in switching power supply during light load is solved, and the effect of preventing noise pollution is achieved.
Patent Information
- Application Number
- CN202311266179.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-25
- Publication Date
- 2025-03-25
AI Technical Summary
When the switching power supply is under light load, the pulse frequency is below 20kHz, resulting in noise pollution.
By detecting the amplitude of the analog signal, the frequency of the driving pulse is determined, and when the switching power supply is in the pulse jump mode, the frequency of the driving pulse is greater than or equal to the preset frequency to prevent noise pollution.
It effectively prevents the operating frequency of the switching power supply from entering the hearing range of the human ear and prevents noise pollution.
Smart Images
Figure CN119696327A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the technical field of switching power supplies, and more specifically, to a switching power supply device, a method for controlling pulse width, and an electronic device. Background Art
[0002] Switching power supplies have the advantages of high efficiency, small size, and light weight, and are widely used in electronic equipment, communication equipment, industrial control systems, and other fields. When a switching power supply (such as a Buck circuit) is in pulse skipping mode, the time between two pulses will become longer and longer, and the frequency will become lower and lower when the load is very light. When the frequency of the pulse is lower than 20kHz, the switching power supply will generate noise pollution. Summary of the invention
[0003] The embodiments of the present application provide a switching power supply device, a method for controlling pulse width, and an electronic device. Various aspects of the embodiments of the present application are introduced below.
[0004] In a first aspect, a switching power supply device is provided, comprising: a conversion circuit for converting an input voltage into an output voltage; a switching circuit connected to the conversion circuit, wherein when the switching circuit is in a first state, the conversion circuit outputs the output voltage, and when the switching circuit is in a second state, the conversion circuit stops outputting the output voltage; and a control circuit connected to the switching circuit, wherein the control circuit comprises: a pulse width adjustment circuit for adjusting the width of a generated initial pulse signal to output a drive pulse, wherein the drive pulse is used to control the switching frequency of the switching circuit; an analog signal generation circuit connected to the pulse width adjustment circuit, wherein the cycle time of the first analog signal is the same as the cycle time of the drive pulse, and the amplitude of the first analog signal has a mapping relationship with the cycle time; and the control circuit is used to perform the following operations: determining the frequency of the drive pulse according to the amplitude of the first analog signal, and controlling the frequency of the drive pulse to be greater than or equal to a preset frequency when the switching power supply device is in a pulse skipping mode, so as to prevent noise pollution to human ears.
[0005] In a second aspect, a method for controlling pulse width is provided, the method being applied to a switching power supply device, the switching power supply device comprising: a conversion circuit for converting an input voltage into an output voltage; a switching circuit connected to the conversion circuit, wherein when the switching circuit is in a first state, the conversion circuit outputs the output voltage, and when the switching circuit is in a second state, the conversion circuit stops outputting the output voltage; and a control circuit connected to the switching circuit, the control circuit comprising: a pulse width adjustment circuit for adjusting the width of a generated initial pulse signal to output a drive pulse, wherein the drive pulse is used to control the switching frequency of the switching circuit; an analog signal generation circuit connected to the pulse width adjustment circuit, and used to generate a first analog signal, wherein the cycle time of the first analog signal is the same as the cycle time of the drive pulse, and the amplitude of the first analog signal has a mapping relationship with the cycle time; the method comprising: determining the frequency of the drive pulse according to the detected amplitude of the first analog signal; and when the switching power supply device is in a pulse skipping mode, controlling the frequency of the drive pulse to be greater than or equal to a preset frequency to prevent noise pollution to human ears.
[0006] In a third aspect, an electronic device is provided, comprising the switching power supply device as described in the first aspect.
[0007] According to a fourth aspect, a non-volatile computer-readable storage medium is provided, on which a computer program is stored, wherein the computer program is used to execute the method according to the second aspect.
[0008] According to a fifth aspect, a computer program product is provided, comprising instructions for executing the method according to the second aspect.
[0009] In an embodiment of the present application, the frequency of the drive pulse is determined by detecting the amplitude of the first analog signal, and the frequency of the drive pulse is controlled to be no less than a preset frequency, which helps to prevent the operating frequency of the switching power supply device from entering the auditory range of the human ear and prevent noise pollution. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a topological diagram of a synchronous BUCK circuit.
[0011] Figure 2 yes Figure 1 Schematic diagram of the waveforms of some components of the circuit.
[0012] Figure 3 yes Figure 1 Schematic diagram of the waveform when the circuit is in continuous conduction mode.
[0013] Figure 4 yes Figure 1 Waveform diagram of the circuit in discontinuous conduction mode.
[0014] Figure 5 yes Figure 1 Schematic diagram of the waveform when the circuit is in pulse skipping mode.
[0015] Figure 6 yes Figure 1 Schematic diagram of the waveform when the circuit is in burst mode.
[0016] Figure 7 yes Figure 1 Schematic diagram of the waveform when the circuit is in forced continuous mode.
[0017] Figure 8 It is a schematic diagram of the structure of a switching power supply device provided in an embodiment of the present application.
[0018] Fig. 9 yes Figure 8 A schematic structural diagram of a possible implementation of a device.
[0019] Figure 10a-Figure 10b It is a schematic diagram of the driving pulse and the triangle wave at different widths.
[0020] Fig.11 It is a schematic diagram of a component unit / partial component unit of an electronic device provided in an embodiment of the present application.
[0021] Fig.12 It is a flow chart of the method for controlling pulse width provided in an embodiment of the present application. DETAILED DESCRIPTION
[0022] 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.
[0023] To facilitate understanding by those skilled in the art, the application scenarios and related terms involved in the embodiments of the present application are first introduced.
[0024] Switching Power Supply
[0025] A switching power supply is a power supply that converts input power into a desired output voltage. It controls the switching state of the input power supply and maintains a stable output voltage by controlling the ratio of the time when the switching element is turned on and off. A switching power supply is generally composed of a pulse width modulation (PWM) control circuit (IC) and a metal-oxide semiconductor field effect transistor (MOSFET). Switching power supplies have the advantages of high efficiency, small size, and light weight, and are widely used in electronic equipment, communication equipment, industrial control systems, and other fields.
[0026] According to the relationship between the output voltage and the input voltage, the switching power supply can be divided into the following types: BUCK circuit (step-down circuit), BOOST circuit (step-up circuit), BUCK-BOOST circuit, etc. Among them, the BUCK circuit is also called BUCK converter or Buck converter. The BUCK-BOOST circuit can achieve both step-up and step-down of the output voltage.
[0027] Buck Circuit
[0028] The following is an exemplary introduction using the BUCK circuit as an example. Figure 1 This is a topological diagram of the synchronous BUCK circuit. Figure 1 As shown, the synchronous BUCK circuit may include MOS tube Q1, MOS tube Q2, inductor L1, capacitor C1 and capacitor C2. MOS tubes Q1 and Q2 are switch elements, and Q1 and Q2 have different combinations of on and off states. MOS tube is the abbreviation of MOSFET tube. In the BUCK circuit, MOS tube Q1 is usually called the upper tube, and MOS tube Q2 is called the lower tube.
[0029] 1) When Q1 is turned on and Q2 is turned off (disconnected). The voltage at the SW terminal is the input voltage V IN , V IN To charge the inductor L1, the inductor current increases, V IN =V L +V OUT , at this time, the voltage of inductor L1 is positive on the left and negative on the right. The direction of current is Figure 1 The dotted line loop.
[0030] 2) When Q1 is turned off, Q2 is turned on. Since the current of inductor L1 cannot change suddenly, the current follows Figure 1 The dot-dash line path forms a loop, giving the load (R load ) is used for power supply, at which time the inductor current decreases. The voltage of the inductor L1 is negative on the left and positive on the right.
[0031] According to the volt-second law, etc., we can deduce an important conclusion of the synchronous buck circuit: the duty cycle is directly related to the input voltage and the output voltage. The duty cycle is the ratio of the on-time of the switch element to the cycle time. Simply put, the lower the output voltage, the lower the duty cycle. In other words, because the output voltage is low, the time required to turn on the MOS tube Q1 to charge the inductor L1 is less.
[0032] Figure 2 yes Figure 1 Waveform diagram of some components of the circuit. Figure 2 As shown, from top to bottom, there are the current schematic diagram of MOS tube Q1, the current schematic diagram of MOS tube Q2, the current schematic diagram of inductor L1, and the voltage schematic diagram at the switch (SW). The specific process is as follows:
[0033] 1) When Q1 is turned on and Q2 is turned off (disconnected, cut off). Vsw is high, I Q1 Increase, I Q2 is zero, and the current in inductor L1 increases.
[0034] 2) When Q1 is off and Q2 is on. Vsw is low, I Q1 is zero, I Q2 decreases, and the current in inductor L1 decreases.
[0035] During the entire steady-state process, the inductor current increases and decreases continuously. The time when the upper tube Q1 is turned on is usually called T on , and its closing time is T off The sum of the two is a period T S .
[0036] According to the waveform of the inductor current, the buck circuit can be divided into two operating modes: continuous conduction mode (CCM) and discontinuous conduction mode (DCM).
[0037] 1) CCM working mode.
[0038] CCM mode: In a switching cycle, the inductor current will not be equal to 0. In other words, the inductor is never "reset", which means that the inductor flux never returns to 0 during the switching cycle. When the power tube is disconnected, there is still current flowing in the coil. Figure 3 yes Figure 1 The waveform diagram of the circuit in continuous conduction mode. Figure 3 As shown in the figure, from top to bottom, the current waveform of the inductor L1, the current (ID) waveform of the MOS tube Q2, and the voltage waveform at SW are shown. It can be seen that in a switching cycle T s Internally, the inductor current (IL ) will not be equal to 0.
[0039] 2) DCM working mode
[0040] DCM mode: At a certain time period in a switching cycle, the inductor current becomes zero. This means that the inductor is properly "reset", that is, when the power switch is closed, the inductor current is zero. Figure 4 Figure 1 The waveform diagram of the circuit in discontinuous conduction mode. Figure 4 As shown, from top to bottom, the current waveform of the inductor L1, the current (ID) waveform of the MOS tube Q2, and the voltage waveform at SW are shown in sequence. It can be seen that in a certain period of time within a switching cycle Ts, the inductor current (IL) will become 0.
[0041] Light load mode of BUCK circuit
[0042] Buck circuit has three operating modes under light load: pulse skipping mode, burst mode and forced continuous mode.
[0043] 1) Pulse skipping mode
[0044] For the controller of the conventional constant frequency Buck circuit, the current of the inductor usually works in CCM mode, and the average current of the inductor is the output load current. When the load current decreases, the average current of the inductor will also decrease; when the load current decreases to a certain value, after the current of the inductor returns to 0, the switching cycle has not ended, the lower tube is turned off (disconnected), and the current of the inductor remains at 0 for a period of time, and then the switching cycle ends. Entering the next switching cycle, the converter is in a complete discontinuous current mode.
[0045] After the Buck converter enters the discontinuous current mode, if the load current is still further reduced, the controller must shield (i.e. skip) some switching pulses to maintain the regulation of the output voltage. This control method is called pulse skipping mode. Pulse skipping mode can provide constant frequency discontinuous current operation in the widest input current range to prevent reverse inductor current.
[0046] Figure 5 yes Figure 1 The waveform diagram of the circuit in pulse skipping mode. Figure 5 As shown in the upper part of the figure, after shielding some pulses of the MOS tube Q1, the pulse waveform of the MOS tube Q1 with increased pulse width can be obtained (as shown in FIG. Figure 5 The average output current is reduced.
[0047] 2) Burst Mode
[0048] The difference between the burst mode and the pulse skipping mode is that the operating frequency is not constant. When the output voltage is lower than a certain threshold, it will send several pulses continuously and then wait for a long time. When the output voltage is lower than the threshold again, the same action will be repeated.
[0049] Figure 6 yes Figure 1 The waveform diagram of the circuit in burst mode. Figure 6 As shown in the lower part of the figure, after shielding some pulses of MOS tube Q1, the number of pulses is two, and the average output current is reduced.
[0050] 3) Forced continuous mode
[0051] When the output load decreases and reaches a certain value, as mentioned above, the pulse skipping mode will enter the DCM mode from the CCM mode. When the current of the inductor is 0, the lower tube Q2 is disconnected (cut off) and remains disconnected until the next switching cycle.
[0052] For forced continuous mode, when the current of the inductor is 0, since the lower tube Q2 is still turned on, the output capacitor voltage will be reversely added to the inductor to reversely excite the inductor, and the current of the inductor will increase from 0 to a certain value. Then the lower tube Q2 is turned off, the main switch tube Q1 is turned on, the input voltage is added to the inductor, the voltage across the inductor is a positive voltage, and the current of the inductor will increase from a certain negative value to a positive value, and continue to increase to a certain value after passing 0. This is also the so-called output current backflow phenomenon.
[0053] Figure 7 yes Figure 1 The waveform diagram of the circuit in forced continuous mode. Figure 7 As shown, during part of the cycle time, the inductor current I L Less than 0.
[0054] For a switching power supply (such as a Buck circuit) operating in pulse skipping mode, when the load is very light, the time between two pulses will become longer and longer, that is, the frequency will become lower and lower. Usually, the frequency that the human ear can hear is 20Hz to 20kHz. That is to say, when the pulse frequency is lower than 20kHz, the switching power supply (voltage converter) will emit a sound that the human ear can hear, thus generating noise pollution.
[0055] It should be noted that the above-mentioned problem that the Buck circuit will generate noise pollution in the pulse skipping mode when lightly loaded is only an example. The embodiments of the present application can be applied to any type of scenario where the pulse width adjustment circuit in the switching power supply will generate noise pollution.
[0056] Therefore, how to develop a technical solution for a switching power supply that prevents noise pollution is a problem that needs to be solved.
[0057] Based on this, an embodiment of the present application proposes a switching power supply device. Figure 8 Schematic diagram of a switching power supply device provided in an embodiment of the present application. A switching power supply device is also called a switching power supply or a power chip. The switching power supply device can be any circuit among a BUCK circuit, a BOOST circuit, and a BUCK-BOOST circuit. Figure 8 As shown, the switching power supply device 800 may include a conversion circuit 810 , a switching circuit 820 and a control circuit 830 .
[0058] The conversion circuit 810 is used to convert an input voltage into an output voltage. The conversion circuit 810 is also called a voltage transformation circuit or a conversion circuit.
[0059] In some implementations, the transformation circuit 810 may include at least one inductive element.
[0060] The switch circuit 820 is connected to the conversion circuit 810. The switch circuit 820 can have multiple working states. When the switch circuit 810 is in the first state, the conversion circuit 810 outputs the aforementioned output voltage. When the switch circuit 820 is in the second state, the conversion circuit 810 stops outputting the output voltage.
[0061] In some implementations, the switch circuit 820 may include one or more switch elements, and the switch elements may be MOS transistors.
[0062] The control circuit 830 is connected to the switch circuit 820, and the control circuit 830 may include a pulse width adjustment circuit 831 and an analog signal generation circuit 832. The control circuit 830 is used to control the frequency of the driving pulse to be greater than or equal to the preset frequency when the switching power supply device is in the pulse skipping mode to prevent noise pollution to the human ear. The frequency that the human ear can hear is 20Hz to 20kHz. The preset frequency can be any frequency greater than 20kHz, for example, the preset frequency can be set to 25kHz.
[0063] The pulse width adjustment circuit 831 is also called a pulse generation and adjustment circuit. The pulse width adjustment circuit 831 is used to generate an initial pulse signal and adjust the width of the generated initial pulse signal to output a driving pulse. The driving pulse is used to control the switching frequency of the switch circuit 820, that is, the frequency of controlling the conduction and disconnection of the switch element of the switch circuit 820.
[0064] The initial pulse signal and the driving pulse are both analog signals. The control signal is usually an analog signal, and the analog signal is used for control, the circuit is simple, easy to implement, and low in cost. The analog signal generating circuit 832 is connected to the pulse width adjustment circuit 831, and is used to generate a first analog signal. In some embodiments, the first analog signal may be a voltage analog signal. The cycle time of the first analog signal is the same as the cycle time of the driving pulse, and the amplitude of the first analog signal has a mapping relationship with the cycle time. The amplitude of the first analog signal may refer to the voltage amplitude of the first analog signal, that is, when the first analog signal is a voltage analog signal, the voltage amplitude of the first analog signal has a mapping relationship with the cycle time. In other embodiments, the first analog signal may be a current analog signal, and the amplitude of the first analog signal may also refer to the current amplitude of the first analog signal.
[0065] The control circuit 830 is used to perform the following operations: determine the frequency of the drive pulse according to the amplitude of the first analog signal, and when the switching power supply device 800 is in the pulse skipping mode, control the frequency of the drive pulse to be greater than or equal to a preset frequency to prevent noise pollution to the human ear.
[0066] In some implementations, the cycle time of the first analog signal is the same as the cycle time of the drive pulse, and the amplitude of the first analog signal is positively correlated with the cycle time. That is, as the cycle time of the drive pulse increases, the amplitude of the first analog signal also increases. The control circuit 830 is used to control the amplitude of the first analog signal to be less than or equal to the first amplitude. Wherein, when the amplitude of the first analog signal is the first amplitude, the frequency of the drive pulse is a preset frequency. It can be understood that the cycle time of the drive pulse is inversely proportional to (negatively correlated with) the frequency.
[0067] In the embodiment of the present application, it is necessary to ensure that the cycle time of the first analog signal is the same as the cycle time (or width) of the driving pulse, and the phase of the first analog signal and the phase of the driving pulse can be the same or different.
[0068] In some implementations, the cycle time of the first analog signal is the same as the cycle time of the driving pulse, and the amplitude of the first analog signal may be negatively correlated with the cycle time. That is, as the cycle time of the driving pulse increases, the amplitude of the first analog signal decreases. At this time, the control circuit 830 is used to control the amplitude of the first analog signal to be greater than or equal to the first amplitude. Wherein, when the amplitude of the first analog signal is the first amplitude, the frequency of the driving pulse is the preset frequency.
[0069] In some implementations, the control circuit 830 may include a detection circuit. The detection circuit is connected to the analog signal generation circuit and is used to detect the voltage amplitude of the first analog signal. The detection circuit may include, for example, an error generator. The error amplifier amplifies the difference between the error signal (such as the first analog signal) and the reference value, which can improve the sensitivity of the control system and improve the adjustment accuracy.
[0070] In some implementations, the first analog signal may be a triangular wave signal. In this case, the analog signal generation circuit is used to generate a triangular wave signal. The amplitude of the triangular wave signal is linearly proportional to the cycle time (or time width), and the linear correlation is good.
[0071] In some implementations, the control circuit 830 may also include a sampling unit, a feedback loop control unit, a driving unit, etc. The sampling unit is used to sample the first analog signal. The feedback loop control unit is used to detect whether the actual output voltage is the set output voltage, and adjust the width and frequency of the driving pulse (or initial pulse signal) according to the difference between the actual output voltage and the set output voltage. The driving unit is used to control the switching state and switching frequency of the switching element in the switching circuit 820 according to the driving pulse.
[0072] In some implementations, the switch circuit 820 may include at least one MOS transistor, and the drive pulse is used to control the switching frequency of the at least one MOS transistor. The conversion circuit 810 includes at least one inductor element.
[0073] In an embodiment of the present application, the frequency of the drive pulse is determined by detecting the amplitude of the first analog signal, and the frequency of the drive pulse is controlled to be greater than or equal to a preset frequency, which helps to prevent the operating frequency of the switching power supply (i.e., the voltage converter) from entering the auditory range of the human ear and prevent noise pollution.
[0074] The switching power supply device of the embodiment of the present application is further described below in combination with some possible implementation methods of the embodiment of the present application.
[0075] Fig. 9 yes Figure 8 A schematic diagram of a possible implementation of the control circuit 830 is shown. Fig. 9 As shown, the control circuit 830 may include: a pulse width adjustment circuit 831, an analog signal generation circuit 832, an adopting unit 833, an error amplifier 834, a feedback loop control unit 835 and a driving circuit 836. The switch circuit 820 may include a MOS transistor Q1 and a MOS transistor Q2. The positions of the MOS transistor Q1 and the MOS transistor Q2 are shown in FIG. Figure 1 The switching power supply is shown in Figure 1. Fig. 9 In the embodiment, other components of the switching power supply device are not shown. Figure 1 Schematic diagram of a switching power supply.
[0076] The pulse width adjustment circuit 831 is used to generate an initial pulse signal and adjust the width of the generated initial pulse signal to output a driving pulse.
[0077] The driving pulse is used to control the frequency of the on and off of the switch elements Q1 and Q2 of the switch circuit 820. When Q1 is on and Q2 is off, that is, when the switch circuit 810 is in the first state, the conversion circuit 810 outputs the aforementioned output voltage; when Q1 is off and Q2 is on, that is, when the switch circuit 820 is in the second state, the conversion circuit 810 stops outputting the output voltage.
[0078] The analog signal generating circuit 832 is used to generate a triangular wave signal. The time length of the triangular wave is the same as the cycle time (cycle width) of the driving pulse, and the amplitude of the triangular wave is proportional to the cycle time of the driving pulse. Fig.10a It is a schematic diagram of a driving pulse and a triangular wave at one width. Fig.10a The upper part is a schematic diagram of the pulse width of the upper tube Q1. At this time, the pulse frequency is about 540kHz and the pulse voltage (V SW ) is approximately 5V. Fig.10a The lower part is a schematic diagram of the width of the triangle wave. The voltage amplitude of the triangle wave (V A ) is approximately 115mV.
[0079] When the cycle time of the driving pulse becomes longer and longer, that is, the frequency of the driving pulse becomes lower and lower, the amplitude of the triangular wave will become larger and larger. Assume that the preset frequency of the lowest limit is 25kHz, and the amplitude of the triangular wave corresponding to 25kHz is 0.8V.
[0080] The sampling unit 833 is used to sample the triangular wave signal generated by the analog signal generating circuit 832 .
[0081] The error amplifier 834 is used to receive the sampling signal, and perform error amplification on the sampling signal of the triangle wave and a reference value (such as 0.8V) and then output the amplified signal.
[0082] The feedback loop control unit 836 is used to detect whether the actual output voltage is the set output voltage, and to enable the pulse width adjustment circuit 831 to adjust the width and frequency of the driving pulse according to the difference between the actual output voltage and the set output voltage.
[0083] The driving circuit 835 is used to control the switching state and switching frequency of the switching element in the switching circuit 820 according to the driving pulse.
[0084] The specific control process of the control circuit 830 may be:
[0085] The sampling unit 833 samples the maximum amplitude of the triangular wave at each cycle time and sends it to the error amplifier 834. When the sampled amplitude is less than the set threshold value (e.g., 0.8V), the error amplifier 834 does not affect the pulse width adjustment circuit 831 (or send an adjustment signal), and only the feedback loop control unit 836 adjusts the width and frequency of the driving pulse (initial pulse signal). That is, the feedback loop control unit 836 sends a signal to make the pulse width adjustment circuit 831 adjust the width and frequency of the initial pulse signal to obtain the desired driving pulse.
[0086] When the sampled amplitude is greater than the set threshold (e.g., 0.8V), the output of the error amplifier 834 begins to affect the pulse width adjustment circuit 831, reducing the width of the drive pulse (i.e., cycle time), thereby reducing the energy transmitted by each drive pulse, and then the feedback loop control unit 836 will increase the frequency of the drive pulse until the pulse frequency is maintained at a preset frequency value (e.g., 25kHz). Fig.10b This is a schematic diagram of a driving pulse and a triangular wave at another width. Fig.10b It is also a waveform diagram under stable operation. Fig.10b As shown, the voltage amplitude of the triangle wave (V A ) is stabilized at around 0.8V and the frequency of the drive pulse is maintained at around 25kHz, thus avoiding noise pollution.
[0087] The embodiment of the present application controls the amplitude of the first analog signal (such as a triangular wave) to be smaller than the first amplitude through the control circuit, so that the frequency of the drive pulse is greater than the preset frequency, which helps to prevent the operating frequency of the switching power supply (voltage converter) from entering the auditory range of the human ear and prevent noise pollution.
[0088] Fig.11 Schematic diagram of a component unit or a partial component unit of an electronic device provided in an embodiment of the present application. Fig.11 As shown, the electronic device 1100 may include a switching power supply device 1110 as described above.
[0089] Combination of the above Figures 1 to 11 The device embodiment of the present application is described in detail. Fig.12 The method embodiment of the present application is described in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so the parts not described in detail can refer to the previous device embodiment.
[0090] Fig.12 It is a flow chart of the method for controlling pulse width provided in an embodiment of the present application. Fig.12The method for controlling pulse width can be applied to a switching power supply device. The switching power supply device includes: a conversion circuit for converting an input voltage into an output voltage; a switching circuit connected to the conversion circuit, when the switching circuit is in a first state, the conversion circuit outputs the output voltage, and when the switching circuit is in a second state, the conversion circuit stops outputting the output voltage; and a control circuit connected to the switching circuit, the control circuit includes: a pulse width adjustment circuit for adjusting the width of the generated initial pulse signal to output a driving pulse, the driving pulse is used to control the switching frequency of the switching circuit; an analog signal generation circuit connected to the pulse width adjustment circuit, for generating a first analog signal, the cycle time of the first analog signal is the same as the cycle time of the driving pulse, and the amplitude of the first analog signal has a mapping relationship with the cycle time. The switching power supply device can be any one of a BUCK circuit, a BOOST circuit, and a BUCK-BOOST circuit.
[0091] Combine the following Fig.12 The method of the embodiment of the present application is described in detail. Fig.12 As shown, the method for controlling the pulse width may mainly include steps S1210 to S1220, and these steps are described in detail below.
[0092] It should be pointed out that the size of the serial numbers of the steps in the embodiments of the present application does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.
[0093] In step S1210, the amplitude of the first analog signal is determined. For example, the first analog signal may be detected by a sampling unit to determine the voltage amplitude of the first analog signal.
[0094] In step S1220, the frequency of the driving pulse is determined according to the amplitude of the first analog signal.
[0095] The frequency of the driving pulse is determined according to the amplitude of the first analog signal and the mapping relationship between the amplitude of the first analog signal and the frequency of the driving pulse.
[0096] In step S1230, when the switching power supply device is in the pulse skipping mode, the frequency of the driving pulse is controlled to be greater than or equal to a preset frequency to prevent noise pollution to human ears.
[0097] Optionally, the cycle time of the first analog signal is the same as the cycle time of the driving pulse, and the amplitude of the first analog signal is positively correlated with the cycle time. Controlling the frequency of the driving pulse to be greater than or equal to a preset frequency may include: controlling the amplitude of the first analog signal to be less than or equal to a first amplitude. When the amplitude of the first analog signal is the first amplitude, the frequency of the driving pulse is the preset frequency.
[0098] Optionally, the first analog signal is a triangular wave signal, and the analog signal generating circuit is used to generate the triangular wave signal.
[0099] Optionally, the switching circuit includes at least one MOS transistor, the driving pulse is used to control the switching frequency of the at least one MOS transistor, and the conversion circuit may include at least one inductor.
[0100] Optionally, the preset frequency is 25kHz.
[0101] The embodiment of the present application controls the amplitude of the first analog signal (such as a triangular wave) to be smaller than the first amplitude through the control circuit, so that the frequency of the driving pulse is greater than the preset frequency, which helps to prevent the operating frequency of the switching power supply from entering the auditory range of the human ear and prevent noise pollution.
[0102] An embodiment of the present application also provides a non-volatile computer-readable storage medium on which a computer program is stored, and the computer program is used to execute any of the methods described above.
[0103] It should be understood that the computer-readable storage medium mentioned in the embodiments of the present application can be any available medium that can be read by a computer or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a digital video disc (DVD)) or a semiconductor medium (e.g., a solid state disk (SSD)), etc.
[0104] An embodiment of the present application further provides a computer program product, which carries a program code, and the instructions included in the program code can be used to execute the steps of the method described in any of the above method embodiments.
[0105] The computer program product may be implemented in hardware, software or a combination thereof. In some embodiments, the computer program product is embodied as a computer storage medium. In other optional embodiments, the computer program product is embodied as a software product, such as a software development kit (SDK).
[0106] It should be understood that electronic devices refer to devices that are composed of electronic components such as integrated circuits, transistors, and electron tubes, and that use electronic technology (including software) to function. Electronic devices may include, but are not limited to, personal digital assistants (PDAs), tablet computers, computers, laptops, ultra-mobile personal computers (UMPCs), netbooks, cellular phones, wearable devices (such as smart watches), augmented reality (AR) devices, virtual reality (VR) devices, MP4 players, car computers, smart home devices, etc.
[0107] In various embodiments of the present application, "first", "second", etc. are used to distinguish different objects rather than to describe a specific order. The size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.
[0108] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
[0109] In several embodiments provided in the present application, it should be understood that when a part is said to be "connected" or "connected" to another part, it means that the part can not only be "directly connected" but also "electrically connected" with another element intervening therebetween. In addition, the term "connected" also means that the part is "physically connected" and "wirelessly connected". In addition, when a part is said to "include" a certain element, unless otherwise stated, it means that the part can include another element, rather than excluding the other element.
[0110] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0111] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
[0112] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.
Claims
1. A switching power supply device, characterized in that: include: A conversion circuit, used for converting an input voltage into an output voltage; a switch circuit connected to the conversion circuit, wherein when the switch circuit is in a first state, the conversion circuit outputs the output voltage, and when the switch circuit is in a second state, the conversion circuit stops outputting the output voltage; as well as, A control circuit is connected to the switch circuit, and the control circuit includes: A pulse width adjustment circuit, used for adjusting the width of the generated initial pulse signal to output a driving pulse, wherein the driving pulse is used for controlling the switching frequency of the switching circuit; an analog signal generating circuit connected to the pulse width adjustment circuit, and configured to generate a first analog signal, wherein a cycle time of the first analog signal is the same as a cycle time of the driving pulse, and an amplitude of the first analog signal and the cycle time have a mapping relationship; The control circuit is used to perform the following operations: determine the frequency of the drive pulse according to the amplitude of the first analog signal, and when the switching power supply device is in a pulse skipping mode, control the frequency of the drive pulse to be greater than or equal to a preset frequency to prevent noise pollution to the human ear.
2. The device according to claim 1, characterized in that The amplitude of the first analog signal is positively correlated with the cycle time. The control circuit is used to control the amplitude of the first analog signal to be less than or equal to a first amplitude. When the amplitude of the first analog signal is the first amplitude, the frequency of the drive pulse is the preset frequency.
3. The device according to claim 2, characterized in that The control circuit comprises: The detection circuit is connected to the analog signal generating circuit and is used to detect the amplitude of the first analog signal.
4. The device according to claim 2, characterized in that The first analog signal is a triangular wave signal, and the analog signal generating circuit is used to generate the triangular wave signal.
5. The device according to any one of claims 1 to 4, characterized in that The switch circuit includes at least one MOS transistor, the drive pulse is used to control the switching frequency of the at least one MOS transistor, and the conversion circuit includes at least one inductor.
6. The device according to any one of claims 1 to 4, characterized in that The preset frequency is 25 kHz.
7. A method for controlling pulse width, characterized in that: The method is applied to a switching power supply device, the switching power supply device comprising: A conversion circuit, used for converting an input voltage into an output voltage; a switch circuit connected to the conversion circuit, wherein when the switch circuit is in a first state, the conversion circuit outputs the output voltage, and when the switch circuit is in a second state, the conversion circuit stops outputting the output voltage; and, A control circuit is connected to the switch circuit, and the control circuit includes: A pulse width adjustment circuit, used for adjusting the width of the generated initial pulse signal to output a driving pulse, wherein the driving pulse is used for controlling the switching frequency of the switching circuit; an analog signal generating circuit connected to the pulse width adjustment circuit, and configured to generate a first analog signal, wherein a cycle time of the first analog signal is the same as a cycle time of the driving pulse, and an amplitude of the first analog signal and the cycle time have a mapping relationship; The method comprises: Determining the frequency of the driving pulse according to the detected amplitude of the first analog signal; When the switching power supply device is in the pulse skipping mode, the frequency of the driving pulse is controlled to be greater than or equal to a preset frequency to prevent noise pollution to human ears.
8. The method according to claim 7, characterized in that The amplitude of the first analog signal is positively correlated with the cycle time, and controlling the frequency of the driving pulse to be greater than or equal to a preset frequency comprises: The amplitude of the first analog signal is controlled to be less than or equal to a first amplitude. When the amplitude of the first analog signal is the first amplitude, the frequency of the driving pulse is the preset frequency.
9. An electronic device, characterized in that: It comprises a switching power supply device as claimed in any one of claims 1 to 6.
10. A non-volatile computer-readable storage medium, characterized in that: A computer program is stored thereon, and the computer program is used to execute the method according to any one of claims 7-8.