Method for performing discontinuous conduction mode pulse control of buck converter and related apparatus

Abstract

A method and related apparatus for performing discontinuous conduction mode (DCM) pulse control of a buck converter to reduce inductor loss is provided. The method may include performing multi-pulse control on the buck converter, causing the buck converter to operate in DCM; and during performing the multi-pulse control on the buck converter to cause the buck converter to operate in the DCM, generating a plurality of pulses per cycle to cause an inductive current of an inductor within the buck converter to be boosted multiple times and then reduced to reduce the inductor loss.

Description

Technical Field

[0001] This invention relates to the design of DC-to-DC converters, and more specifically, to a method and related apparatus for performing discontinuous conduction mode (DCM) pulse control of a buck converter to reduce inductor losses. Background Technology

[0002] According to relevant technologies, a buck converter is a DC-to-DC converter used to convert high voltage to low voltage. In commercially available buck converters, the power efficiency (PE) under light load is primarily affected by inductor losses. For example, inductor losses typically include copper losses (often referred to as direct current resistance losses, or simply "DCR") and core losses. The core loss in an inductor is mainly caused by the alternating magnetic field in the core material. Since core losses depend on the operating frequency and the total flux swing, they can vary depending on the magnetic material. Furthermore, core losses are usually not included in the Simulation Program with Integrated Circuit Emphasis (SPICE) models provided by the inductor supplier. Even with the same inductance rating value, core losses can differ significantly between different suppliers, thus affecting the power efficiency of the buck converter. Therefore, a novel approach and its associated architecture are needed to address these issues without introducing any side effects or in a way that is unlikely to introduce side effects. Summary of the Invention

[0003] The purpose of this invention is to provide a method and related apparatus for performing DCM pulse control of a buck converter to reduce inductor losses, thereby solving the aforementioned problems.

[0004] At least one embodiment of the present invention provides a method for performing DCM pulse control of a buck converter to reduce inductor losses. The method may include: performing multi-pulse control on the buck converter to operate it in DCM; and during the multi-pulse control to operate the buck converter in DCM, generating multiple pulses per cycle to repeatedly increase and then decrease the inductor current of an inductor within the buck converter to reduce inductor losses.

[0005] At least one embodiment of the present invention provides an apparatus for performing DCM pulse control of a buck converter to reduce inductor losses, wherein the apparatus may include a multi-pulse control circuit configured to perform multi-pulse control on the buck converter, causing the buck converter to operate in DCM. For example, during the multi-pulse control of the buck converter to operate in DCM, the multi-pulse control circuit may be configured to generate multiple pulses per cycle to cause the inductor current of the inductor within the buck converter to rise and then fall multiple times, thereby reducing the inductor losses.

[0006] The phrase "multiple increases followed by decreases" refers to the process of increasing (growing) and then decreasing (decreasing) occurring multiple times; "multiple times" can mean two times, three times, etc.

[0007] According to some embodiments, the device may include at least one portion (e.g., one or more portions) of the buck converter. For example, the device may include the multi-pulse control circuit described above. In another example, the device may include the multi-pulse control circuit and the drive circuit (or "driver") of the buck converter. In some examples, the device may include the buck converter, and the multi-pulse control circuit is integrated into the buck converter.

[0008] The advantage of this invention is that the method and related apparatus, such as the multi-pulse control circuit, can perform multi-pulse control to achieve energy saving (e.g., energy saving is achieved because the reduction in core losses outweighs the increase in on / off switching losses of the switching devices in the buck converter). Furthermore, the method and related apparatus, such as the multi-pulse control circuit, can solve problems in the related art without introducing any side effects or in a manner that minimizes the possibility of introducing side effects.

[0009] These and other objects of the present invention will undoubtedly become apparent to those skilled in the art upon reading the preferred embodiments described below in detail. Attached Figure Description

[0010] Figure 1 A multi-pulse control scheme is shown as a method for implementing discontinuous conduction mode (DCM) pulse control in a buck converter to reduce inductor losses. The lower half of the diagram illustrates this scheme. Figure 1 The upper part shows the single-pulse control scheme of the buck converter for better understanding.

[0011] Figure 2 The invention relates to embodiments thereof. Figure 1 The inductor current of the multi-pulse control scheme shown is, for example, an inductor current with a periodic curve corresponding to multiple cycles.

[0012] Figure 3 An apparatus for performing discontinuous conduction mode (DCM) pulse control of a buck converter to reduce inductor losses is shown, wherein a multi-pulse control circuit can be integrated into the buck converter.

[0013] Figure 4 This illustrates an embodiment of the present invention. Figure 3 The diagram shows the relevant signals of the buck converter.

[0014] Figure 5 This illustrates an embodiment of the present invention. Figure 3 A schematic diagram of the relevant parameters of the multi-pulse control circuit is shown.

[0015] Figure 6 This illustrates an embodiment of the present invention. Figure 3 The diagram shows multiple sub-circuits of the multi-pulse control circuit and related operations of these sub-circuits.

[0016] Figure 7 This illustrates a peak / valley time control scheme according to an embodiment of the present invention.

[0017] Figure 8 This illustrates an embodiment of the present invention. Figure 7 Some implementation details of the peak / valley time control scheme shown.

[0018] Figure 9 This is a flowchart of a method according to an embodiment of the present invention. Detailed Implementation

[0019] In the following description and claims, certain terms are used to refer to specific components. Those skilled in the art will understand that electronic device manufacturers may use different names to refer to the same component. This application is not intended to distinguish between components with different names but the same function. In the following description and claims, the terms "comprising" and "including" are used in an open-ended manner and should therefore be interpreted as "including but not limited to...". Furthermore, the term "coupled" means that it can be an indirect or direct electrical connection. Thus, if one device is coupled to another device, the connection can be a direct electrical connection or an indirect electrical connection via other devices and connections.

[0020] Figure 1 The lower half illustrates a multi-pulse control scheme based on an embodiment of the present invention for performing discontinuous conduction mode (DCM) pulse control of a buck converter to reduce inductor losses. Figure 1 The upper part illustrates the single-pulse control scheme for the buck converter for better understanding. It is assumed that one or more functions of the buck converter can be temporarily disabled to allow the buck converter to control according to... Figure 1The single-pulse control scheme shown in the upper part is applicable, but the invention is not limited thereto. Based on the single-pulse control scheme, the buck converter can be configured to generate a single pulse per cycle on the control signal PWM0 (e.g., a normal pulse width modulation signal with one pulse per cycle) to control the buck converter, thereby controlling the inductor current I0 of the inductor within the buck converter. L It only increases (grows) and then decreases (decreases) once per cycle before reaching zero current (e.g., an inductor current value equal to zero).

[0021] like Figure 1 As shown in the lower half, the buck converter can operate according to a multi-pulse control scheme to perform multi-pulse control on the buck converter, enabling it to operate in DCM for energy saving. Specifically, during the multi-pulse control of the buck converter to operate in DCM, multiple pulses per cycle are generated on the control signal PWM (e.g., an unconventional pulse width modulation signal with more than one pulse per cycle) to control the buck converter so that the inductor current I of the inductor within the buck converter is increased (increased) and then decreased (decreased) multiple times per cycle before reaching zero current (e.g., an inductor current value equal to zero). L This reduces inductor losses, thereby achieving better overall performance.

[0022] To better understand, the symbol "PWM" in control signal PWM0 stands for Pulse Width Modulation, indicating that control signal PWM0 is a pulse width modulated signal, such as the ordinary pulse width modulated signal mentioned above; the symbol "PWM" in control signal PWM stands for Pulse Width Modulation, indicating that control signal PWM is a pulse width modulated signal, such as the unconventional pulse width modulated signal mentioned above.

[0023] According to some embodiments, the buck converter (or the control circuitry operating according to this method) can reduce core losses by effectively controlling the DCM pulse and can precisely adjust the valley level of the DCM pulse and promote the generation of multiple pulses in the DCM. Core losses in the inductor can be reduced by decreasing the root mean square current (IRMS) and switching frequency Fsw of the inductor current. For example, the related operations of the multiple sub-methods #1, #2, and #3 (or simply "methods 1, 2, and 3") in this method may include: Method 1: Reduce DCM pulse peak current by implementing multi-pulse control, where reducing the DCM pulse peak current will lead to an increase in RMS current I. RMS The reduction; Method 2: Utilize multi-pulse control to precisely adjust peak and valley levels while maintaining or increasing the charge in the inductor. For example, this configuration allows for a reduction in the switching frequency Fsw, where Fsw = (1 / Ts) and “Ts” represents the occurrence period of the multi-pulse / double peak, such as the occurrence period of multiple pulses and / or double peaks in a multi-pulse control scheme. Method 3: Effectively manage the switching loss of the switching device in the buck converter, such as the switching loss of at least one switching device in the buck converter, where the switching device can be a metal oxide semiconductor field effect transistor (MOSFET), such as a P-type MOSFET (or simply "PMOS"), an N-type MOSFET (or simply "NMOS"), or both.

[0024] Figure 2 The invention relates to embodiments thereof. Figure 1 The inductor current shown in the multi-pulse control scheme, for example, the inductor current I. L It has a periodic curve corresponding to multiple cycles. The buck converter (or the control circuit therein) can achieve energy saving because, due to multi-pulse control, the combined reduction of core losses from sub-method #1 (or "method 1") and sub-method #2 (or "method 2") outweighs the increase in on / off switching losses of at least one of the aforementioned switching devices (e.g., PMOS and NMOS) in the buck converter.

[0025] Figure 3 An apparatus for performing DCM pulse control on a buck converter 10 to reduce inductor losses is shown, wherein the apparatus may include at least a portion (e.g., one or more portions) of the buck converter 10. More specifically, the apparatus may include the buck converter 10, and a multi-pulse control circuit 100 may be integrated into the buck converter 10. Figure 3As shown, the buck converter 10 includes a multi-pulse control circuit 100, a drive circuit 11 (or simply "driver 11"), and an output stage circuit located after the driver 11. The output stage circuit includes at least one switching device (e.g., multiple switching devices MHS and MLS), an inductor (e.g., inductor 12), a zero-current detector 13, and a capacitor coupled to the inductor 12. The multi-pulse control circuit 100 can be configured to perform the multi-pulse control described above, the driver 11 can be configured to drive the output stage circuit under the control of a control signal PWM from the multi-pulse control circuit 100, and the output stage circuit can be configured to convert the input voltage VIN of the buck converter 10 into the output voltage VOUT of the buck converter 10. For example, the multiple switching devices MHS and MLS can be MOSFETs, such as P-type MOSFETs (or "PMOS") and N-type MOSFETs (or "NMOS"), respectively, and the driver 11 can be equipped with logic circuitry, such as output logic circuitry (or simply "OUTLGC"), to generate multiple gate control signals UGATE and LGATE based on the control signal PWM or the zero-current detection result from the zero-current detector 13. This allows the driver 11 to control the multiple switching devices MHS and MLS using the gate control signals UGATE and LGATE respectively, to operate according to the control signal PWM from the multi-pulse control circuit 100 and the zero-current detection result ZC from the zero-current detector 13. The zero-current detector 13 can detect the inductor current I of the inductor 12. L Whether it equals zero current, to generate a zero current detection result ZC, used to indicate the inductor current I. L Whether zero current is achieved. To better understand, the buck converter 10 and the multi-pulse control circuit 100 can be cited as examples of the buck converter and the control circuit therein in the foregoing embodiments, respectively, but the invention is not limited thereto. According to some embodiments, the architecture of the buck converter 10 and / or the multi-pulse control circuit 100 may differ. For example, the multiple switching devices MHS and MLS can both be N-type MOSFETs.

[0026] Figure 4 This is illustrated in the embodiments of the present invention. Figure 3 The diagram shows the relevant signals of the buck converter 10. The buck converter 10 (or the multi-pulse control circuit 100 therein) can be configured to perform multi-pulse control on the buck converter 10, causing it to operate in DCM mode to achieve energy savings. This is because the reduction in core losses outweighs the increase in on / off switching losses of at least one of the aforementioned switching devices (e.g., the multiple switching devices MHS and MLS within the buck converter 10). Figure 4 As shown, in any one of the multiple cycles of the inductor current, the inductor current I LThis includes a controllable inductor current valley and two inductor current peaks, which can be simply referred to as "controllable I". L "Valley" and "Two I's" L The two inductor current peaks have the same peak value. For example, the controllable inductor current valley (or "I") L The valley value of the inductor current peak (or "I") can be equal to or greater than zero but less than either of the two inductor current peaks (or "I"). L The peak value of the controlled inductor current (or "controlled I"). L The valley) and the two inductor current peaks with the same peak value (or "two I" peaks) L The multi-pulse control can more effectively control the ratio of core losses to switching losses in the buck converter 10 (or its switching devices, such as switching devices MHS and MLS), thereby achieving optimal conversion efficiency. This is for illustrative purposes only and does not imply limitation of the invention. According to some embodiments, in any one of the multiple cycles of the aforementioned inductor current, the inductor current I... L The system may include at least two inductor current peaks and at least one inductor current valley, wherein the two inductor current peaks may represent any two of the at least two inductor current peaks, and the controllable inductor current valley may represent the inductor current valley between any two inductor current peaks. In some embodiments, all inductor current peaks in the at least two inductor current peaks have the same peak value, and the valley value of the inductor current valley between any two inductor current peaks is greater than zero and less than the peak value of any one of the at least two inductor current peaks. In some embodiments, the valley value of the inductor current valley between any two inductor current peaks is greater than zero and less than the peak value of any one of the at least two inductor current peaks.

[0027] The multi-pulse control circuit 100 can generate at least one control signal (e.g., one or more control signals), such as a control signal PWM. When the buck converter 10 needs to provide load current, particularly when obtaining load current from a source providing the input voltage VIN, the multi-pulse control circuit 100 can generate the control signal PWM to the driver 11, causing the driver 11 to generate a gate control signal UGATE for controlling the switching device MHS and a gate control signal LGATE for controlling the switching device MLS. The gate control signals UGATE and LGATE are used to control the switching devices MHS and MLS such that the current waveform of the inductor 12 in the buck converter 10 is a waveform with multiple peaks.

[0028] Table 1

[0029] Table 1 shows the on / off states of the switching devices MHS and MLS in multiple stages {stage (1), stage (2), stage (3), stage (4), stage (5)} of a period Ts. For better understanding, the off states of the switching devices MHS and MLS are shown in [the table]. Figure 4 The MHS and MLS are marked as "MHS Off" and "MLS Off", respectively, while the on states are marked as "MHS On" and "MLS On". The multi-pulse control circuit 100 can control the driver 11 to turn the switching devices MHS and MLS on / off in multiple stages {stage (1), stage (2), stage (3), stage (4), stage (5)} of the period Ts via a control signal PWM. By using the multi-pulse control circuit 100 to control the switching devices MHS and MLS in the buck converter 10 (e.g., for cases using different types of transistors, respectively...), the switching devices MHS and MLS in the buck converter 10 can be controlled (e.g., for cases using different types of transistors, respectively...). Figure 3 The switching of the PMOS and NMOS shown, or, in the case of using the same type of transistor, one NMOS and another NMOS respectively, the inductor current I L It can produce waveforms with multiple peaks. Further implementation details of the multi-pulse control circuit 100 will be described with reference to the following figures.

[0030] Figure 5 This illustrates an embodiment of the present invention. Figure 3 The diagram shows the relevant parameters of the multi-pulse control circuit 100, where the inductor current I... L The rise / fall can be simply referred to as I. L The rise / fall. The buck converter 10 (or the multi-pulse control circuit 100 therein) can control the rise / fall corresponding to the first I. L The rising stage (1), corresponding to the first I L The descent phase (2), corresponding to the second I L The rising stage (3) and corresponding to the second I L The duration of the falling phase (4), for example, the rise time of the first inductor current (T). ON,DCM ), first inductor current fall time (A*T) OFF,DCM ), rise time of the second inductor current (A*T) ON,DCM ) and the fall time of the second inductor current (T) OFF,DCM (hereinafter referred to as the First I) L Rise time (T) ON,DCM ), First I L Fall time (A*T) OFF,DCM ), Second I L Ascent time (A*T)ON,DCM ) and the second I L Fall time (T) OFF,DCM ), where the first I L Rise time (T) ON,DCM ) and current I ON,DCM Proportional (abbreviated as " ), the second I L Fall time (T) OFF,DCM ) and current I OFF,DCM Proportional (abbreviated as " (The second I) L Ascent can be the first I L The next rise of I L rise.

[0031] Figure 6 Illustration of an embodiment of the present invention Figure 3 The diagram shows multiple sub-circuits of the multi-pulse control circuit 100 and their related operations. The multiple sub-circuits of the multi-pulse control circuit 100 may include multiple modules #1, #2, #3, #4, #5, and #6 (referred to as "modules 1, 2, 3, 4, 5, and 6"), which can achieve the following: Module 1: Voltage-to-current converter 110, configured to generate current I ON,CCM This current may involve VIN information, such as information about the input voltage VIN (e.g., voltage level). For example, the voltage-to-current converter 110 can perform voltage-to-current conversion on the input voltage VIN to generate a current I. ON,CCM , where the current I ON,CCM Proportional to the input voltage VIN (abbreviated as " The input voltage VIN represents the supply voltage of the buck converter 10. Module 2: On-time current gain circuit 120, configured to adjust I ON,DCM Gain (which can be considered as the on-time current gain controlled by the on-time current gain circuit 120), for example, the on-time current gain circuit 120 can be determined according to Equation I ON,DCM = (E *I ON,CCM Change the current to change the current I ON,CCM Converted to current I ON,DCM In this equation, the on-time current gain can be implemented as the on-time current ratio E,I. ON,DCM = (E *I ON,CCM The on-time current ratio E can be equal to a first predetermined value, such as a first positive value. The on-time current ratio E can be set based on the ideal efficiency of the buck converter; Module 3: Rise time control circuit 130, configured to control the first I of the waveformL Rise time (T) ON,DCM ) and the second I L Ascent time (A*T) ON,DCM For example, the rise time control circuit 130 can generate a first I... L Rise time (T) ON,DCM ) and the second I L Ascent time (A*T) ON,DCM ), where the first I L Rise time (T) ON,DCM ) and the second I L Ascent time (A*T) ON,DCM Both are related to current I ON,DCM Proportional to, and more specifically, controlling a first level time period and another first level time period of the first level (e.g., high level) of the control signal PWM respectively, to control the first I of the inductor current waveform respectively. L Rise time (T) ON,DCM ) and the second I L Ascent time (A*T) ON,DCM ), where “A” can be equal to a second predetermined value, such as a second positive value; Module 4: Turn-off time current gain circuit 140, configured to adjust I OFF,DCM The gain (which can be considered as the off-time current gain controlled by the off-time current gain circuit 140), for example, the off-time current gain circuit 140 can be determined according to Equation I OFF,DCM = ((K / A) *I ON,DCM Change the current to change the current I ON,DCM Converted to current I OFF,DCM In this equation, the turn-off time current gain can be expressed as the turn-off time current ratio (K / A), I OFF,DCM = ((K / A) *I ON,DCM “K” is an arbitrary constant, and the arbitrary constant K can be equal to a third predetermined value, such as a third positive value; Module 5: Fall time control circuit 150, configured to control the first I of the waveform. L Fall time (A*T) OFF,DCM For example, the fall time control circuit 150 can generate a first I... L Fall time (A*T) OFF,DCM ), where the first I L Fall time (A*T) OFF,DCM ) and current I OFF,DCM Proportional to, more specifically, the second level time period of the second level (e.g., low level) of the control signal PWM to control the inductor current I. L The first I of the waveform LFall time (A*T) OFF,DCM ), where “A” can be equal to a second predetermined value, such as a second positive value; Module 6: Pulse Width Modulation Control Circuit 160, hereinafter referred to as PWM Control Circuit 160, is configured to generate and output a control signal PWM (or "PWM signal") for multi-pulse control to driver 11 to perform multi-pulse control on buck converter 10. For example, PWM Control Circuit 160 can at least based on a first I L Rise time (T) ON,DCM ), First I L Fall time (A*T) OFF,DCM ) and the second I L Ascent time (A*T) ON,DCM Generate a control signal PWM, and make the control signal PWM have the following characteristics: Figure 5 The waveforms shown correspond to the relevant parameters; Modules 1, 2, 3, 4, 5, and 6 can be implemented by at least one active component (e.g., one or more current sources), at least one passive component (e.g., one or more resistors), and / or at least one logic circuit (e.g., one or more logic gates), but the invention is not limited thereto. Modules 1, 2, 3, 4, 5, and 6 can be implemented using various circuits as long as it does not impede the implementation of the invention. Furthermore, the multiple sub-circuits of the multi-pulse control circuit 100 may also include multiple switches, such as switches SW1 and SW2.

[0032] like Figure 6 As shown, switch SW1 can be configured to selectively connect module 2 (e.g., on-time current gain circuit 120) and module 3 (e.g., rise time control circuit 130) to allow current I... ON,DCM The current is transferred from the on-time current gain circuit 120 to the rise time control circuit 130, as indicated by the right-hand arrow shown by the dashed line. Switch SW2 can be configured to selectively connect module 2 (e.g., on-time current gain circuit 120) and module 4 (e.g., off-time current gain circuit 140) to allow current I to flow from the on-time current gain circuit 120 to the rise time control circuit 130. ON,DCM The current is transferred from the on-time current gain circuit 120 to the off-time current gain circuit 140, as indicated by the downward arrow shown by the dashed line. For example, the multi-pulse control circuit 100 can control the selective connection of either switch SW1 or SW2, and related operations may include: (1) When the buck converter 10 needs to provide load current, switch SW1 will be turned on and switch SW2 will be turned off. The rise time control circuit 130 generates a time-to-rise time (RTD) control signal for the first I. L Rise time (T) ON,DCM ) signal; (2) In the first I LRise time (T) ON,DCM After the turn-off period ends, switch SW1 will be turned off and switch SW2 will be turned on. During the turn-off time, the current gain circuit 140 will apply the current gain (e.g., (K / A)) to the current I. ON,DCM To generate current I OFF,DCM The fall time control circuit 150 generates a time-to-fall time control circuit for controlling the first I L Fall time (A*T) OFF,DCM The signal; (3) In the first I L Fall time (A*T) OFF,DCM After the event concludes, switch SW1 will be turned on and switch SW2 will be turned off. The rise time control circuit 130 generates a time generator to control the second I. L Ascent time (A*T) ON,DCM The signal; and (4) Finally, when the second I L Ascent time (A*T) ON,DCM When the operation ends, both switches SW1 and SW2 will be turned off, and the inductor current I will decrease. L It will drop until it reaches zero current and is stopped by zero current detector 13.

[0033] Figure 7 This is a schematic diagram of the peak and valley time control scheme according to an embodiment of the present invention. The current waveform of the inductor 12 in the buck converter 10 under multi-pulse control (e.g., inductor current I) L The waveform shows multiple peaks, specifically, these peaks may include two equal peaks. For better understanding, I... L Peak refers to the peak current of inductor 12, such as the inductor current I as shown in its curve. L The peak value of I L Valley refers to the valley current of inductor 12, such as the inductor current I as shown in its curve. L The valley value. Furthermore, the valley current between the two peaks is equal to or greater than zero but less than I. L Peak value. For example... Figure 7 As shown, the first I L Rise time, for example, T ON,DCM This refers to the current in the inductor (e.g., inductor current I). L From zero current to I L The time required to reach the peak, the first I L Fall time, for example, A*T OFF,DCM This refers to the current in the inductor (e.g., inductor current I). L ) from I L Peak drops to I L The time required for the trough, the second I LRise time, e.g., A*T ON,DCM This refers to the current in the inductor (e.g., inductor current I). L ) from I L The trough rose to I L The time required to reach the peak, the second I L Fall time, for example, T OFF,DCM This refers to the current in the inductor (e.g., inductor current I). L ) from I L The time required for the peak current to drop to zero. Regarding the parameter (A*T) OFF,DCM ) and (A*T ON,DCM ), where parameter A can be equal to 1 minus I L Valley value divided by I L The division result obtained from the peak value can therefore be expressed as: .

[0034] In addition, Figures 5 to 7 In the relevant parameters shown in the embodiments, some parameters have "DCM" (e.g., T) in their subscripts. ON,DCM 、(A*T OFF,DCM (A*T) ON,DCM ), T OFF,DCM I ON,DCM and I OFF,DCM ) indicates that inductor 12 is in discontinuous conduction mode (DCM).

[0035] Figure 8 This is an illustration of an embodiment of the present invention. Figure 8 The diagram illustrates some implementation details of the peak and valley time control scheme, where the horizontal axis can represent the period Ts measured in microseconds (e.g., the multi-pulse / double-peak occurrence period Ts) (labeled "Ts(μs)" for simplicity), and the vertical axis can represent the inductor current I measured in amperes. L (For simplicity, it is marked as "I") L (A)”). Parameter (A*T) OFF,DCM ) and (A*T ON,DCM The parameter A of (A*T) can be changed so that the parameter (A*T) OFF,DCM ) and (A*T ON,DCM ) Change accordingly, for example, such as Figure 8 The vertical line drawn below the curve shown is indicated by a dashed line. For better understanding, in... Figure 8 Examples of A = 1 - (5 / 6), A = 1 - (4 / 6), A = 1 - (3 / 6), A = 1 - (2 / 6), A = 1 - (1 / 6), and A = 1 - (0 / 6) are shown, but the invention is not limited thereto. More examples of other values ​​for the parameter A can be found in [the document / reference]. Figure 8 This is further illustrated in the text.

[0036] The buck converter 10 (or its multi-pulse control circuit 100) based on the method operation can control I by adjusting parameter A. L Valley value. For example, parameter A is controlled by the off-time current gain circuit 140, through controlling I. OFF,DCM Current gain (e.g., (K / A)) affects the first I L Fall time (A*T) OFF,DCM Parameter A can also be used to adjust I by using the rise time control circuit 130. ON,DCM To control the second I L Ascent time (A*T) ON,DCM Ultimately, consistent I will be achieved. L Peak value. Through controllable I L Valley value and two identical I L Peak voltage, buck converter 10 (or its multi-pulse control circuit 100) can more effectively control the ratio of core loss to switching loss, thereby achieving optimal conversion efficiency.

[0037] Figure 9 A flowchart illustrating a method according to an embodiment of the present invention is shown. The buck converter 10 and the multi-pulse control circuit 100 therein can be configured according to... Figure 9 The workflow shown is as follows.

[0038] In step S11, the multi-pulse control circuit 100 can perform multi-pulse control on the buck converter 10 to enable the buck converter 10 to operate in DCM to achieve energy saving, since the reduction in core losses outweighs the increase in on / off switching losses of at least one switching device (e.g., multiple switching devices MHS and MLS) within the buck converter 10.

[0039] In step S12, during the multi-pulse control of the buck converter 10 to enable its operation in the DCM, the multi-pulse control circuit 100 can generate multiple pulses per cycle on the control signal PWM (e.g., a special pulse width modulation signal with multiple pulses per cycle) to control the buck converter 10 to increase (increase) and then decrease (decrease) the inductor current I of the inductor 12 within the buck converter 10 multiple times in each cycle (e.g., cycle Ts) before reaching zero current (e.g., the inductor current value is equal to zero). L This is to reduce inductor losses. "Multiple increases followed by decreases" refers to the process of increasing (growing) and then decreasing (decreasing) occurring multiple times; "multiple times" can mean two, three, etc.

[0040] To better understand this method, it can be used... Figure 9The workflow shown is illustrated, but the invention is not limited thereto. According to some embodiments, it is possible to... Figure 9 Add, delete, or change one or more steps in the workflow shown.

[0041] As can be seen from the foregoing, it is understood that various embodiments of this application have been described herein for illustrative purposes, and various modifications may be made without departing from the scope and spirit of this application. Therefore, the various embodiments disclosed herein are not intended to be limiting, and the true scope and spirit are determined by the appended claims.

Claims

1. A method for performing discontinuous conduction mode (DCM) pulse control to reduce inductor losses, characterized in that, include: Multi-pulse control is applied to the buck converter to enable it to operate in the DCM. as well as During the multi-pulse control of the buck converter to enable its operation in the DCM, multiple pulses are generated per cycle to cause the inductor current in the buck converter to rise and then fall multiple times, thereby reducing inductor losses.

2. The method as described in claim 1, characterized in that, Performing the multi-pulse control on the buck converter to enable it to operate in the DCM includes: The multi-pulse control is applied to the buck converter to make it operate in the DCM such that the reduction in core losses outweighs the increase in on / off switching losses of at least one switching device within the buck converter, thereby achieving energy savings.

3. The method as described in claim 1, characterized in that, In any one of the multiple cycles of the inductor current, the inductor current includes a controllable inductor current valley and two inductor current peaks, wherein the controllable inductor current valley is located between the two inductor current peaks, and wherein the two inductor current peaks have the same peak value.

4. The method as described in claim 3, characterized in that, The valley value of the controllable inductor current valley is equal to or greater than zero, but less than the peak value of either of the two inductor current peaks.

5. The method as described in claim 3, characterized in that, By controlling the inductor current valley and the two inductor current peaks, the multi-pulse control effectively controls the ratio of core loss to switching loss of the buck converter.

6. The method as described in claim 1, characterized in that, In any one of the multiple cycles of the inductor current, the inductor current includes at least two inductor current peaks and at least one inductor current valley.

7. The method as described in claim 6, characterized in that, All inductor current peaks in at least two inductor current peaks have the same peak value.

8. The method as described in claim 6, characterized in that, The valley value of the inductor current valley between any two inductor current peaks is greater than zero and less than the peak value of any one of the at least two inductor current peaks.

9. An apparatus for performing discontinuous conduction mode (DCM) pulse control of a buck converter to reduce inductor losses, characterized in that, The device includes: A multi-pulse control circuit is configured to perform multi-pulse control on the buck converter, enabling the buck converter to operate in the DCM. Specifically, during the multi-pulse control of the buck converter to enable its operation in the DCM, the multi-pulse control circuit is configured to generate multiple pulses per cycle to cause the inductor current of the inductor within the buck converter to rise and then fall multiple times, thereby reducing inductor losses.

10. The apparatus as claimed in claim 9, characterized in that, The multi-pulse control circuit is configured to perform the multi-pulse control on the buck converter to make the buck converter operate in the DCM to achieve energy saving, such that the reduction in core losses outweighs the increase in on / off switching losses of at least one switching device within the buck converter.

11. The apparatus as claimed in claim 9, characterized in that, In any one of the multiple cycles of the inductor current, the inductor current includes a controllable inductor current valley and two inductor current peaks, wherein the controllable inductor current valley is located between the two inductor current peaks and the two inductor current peaks have the same peak value.

12. The apparatus as claimed in claim 11, characterized in that, The valley value of the controllable inductor current valley is equal to or greater than zero, but less than the peak value of either of the two inductor current peaks.

13. The apparatus as claimed in claim 11, characterized in that, By controlling the inductor current valley and the two inductor current peaks, the multi-pulse control effectively controls the ratio of core loss to switching loss of the buck converter.

14. The apparatus as claimed in claim 11, characterized in that, In any one of the multiple cycles of the inductor current, the inductor current includes at least two inductor current peaks and at least one inductor current valley.

15. The apparatus as claimed in claim 14, characterized in that, All inductor current peaks in at least two inductor current peaks have the same peak value.

16. The apparatus as claimed in claim 14, characterized in that, The valley value of the inductor current valley between any two inductor current peaks is greater than zero and less than the peak value of any one of the at least two inductor current peaks.

17. The apparatus as claimed in claim 9, characterized in that, The multi-pulse control circuit includes: A voltage-to-current converter is configured to generate a first current corresponding to the input voltage of the buck converter; A conduction-time current gain circuit, coupled to the voltage-to-current converter, is configured to convert the first current into a second current according to the conduction-time current gain. A rise time control circuit, coupled to the on-time current gain circuit, is configured to control the first and second inductor current rise times of the inductor current waveform according to the second current. A turn-off time current gain circuit, coupled to the turn-on time current gain circuit, is configured to convert the second current into a third current based on the turn-off time current gain; and A fall time control circuit, coupled to the turn-off time current gain circuit, is configured to control the first inductor current fall time of the inductor current waveform according to the third current.

18. The apparatus as claimed in claim 17, characterized in that, The control signal of the multi-pulse control is used to control the buck converter; the rise time control circuit is configured to control a first level time period and another first level time period of the first level of the control signal, so as to control the first inductor current rise time and the second inductor current rise time of the inductor current waveform, respectively. The fall time control circuit is configured to control the second level of the control signal for a second level time period to control the first inductor current fall time of the inductor current waveform.

19. The apparatus as claimed in claim 17, characterized in that, The multi-pulse control circuit also includes: A pulse width modulation control circuit, coupled to the rise time control circuit and the fall time control circuit, is configured to generate the control signal for multi-pulse control of the buck converter.

20. The apparatus as claimed in claim 9, characterized in that, The device includes the buck converter, and the multi-pulse control circuit is integrated into the buck converter.

Images