Computing device

Abstract

The embodiment of the invention provides computing equipment. The computing device comprises a power supply module, the power supply module comprises a control circuit and a bridgeless totem-pole power factor correction (PFC) circuit, the bridgeless totem-pole PFC circuit comprises a main switch tube and a follow current tube, and the control circuit is connected with the follow current tube and the main switch tube; the control circuit is used for monitoring circuit parameters of the bridgeless totem pole PFC circuit; querying a preset table according to the circuit parameters, and determining dead zone duration and a negative current threshold value; the preset table indicates the corresponding relation between the circuit parameters and the dead zone duration and the negative current threshold value; controlling the freewheeling tube to be disconnected according to the negative current threshold value; and controlling the main switch tube to be turned on under the zero voltage condition according to the dead zone duration. According to the computing device provided by the embodiment of the invention, the compensated negative current signal can be matched with the actual negative current signal requirement, so that the loss of the bridgeless totem pole PFC circuit under the zero-voltage starting condition is reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of server technology, and in particular to a computing device. Background Art

[0002] During the use of a bridgeless totem-pole power factor correction (PFC) circuit, a control circuit can reduce the turn-on loss of the main switch tube by controlling the main switch tube of the bridgeless totem-pole PFC circuit to turn on under zero voltage conditions, thereby improving the efficiency of the bridgeless totem-pole PFC circuit.

[0003] In the related art, a control circuit can calculate a negative current threshold based on the peak value of the input voltage signal of the bridgeless totem-pole PFC circuit, and then control the freewheeling tube to disconnect based on the fixed negative current threshold to compensate for the negative current signal of the inductor in the bridgeless totem-pole PFC circuit. The compensated negative current signal can then drain the charge in the parasitic capacitance of the main switch tube, thereby turning on the main switch tube under zero voltage conditions.

[0004] However, the method in the related art has the problem that the compensated negative current signal does not match the actual demand, thereby increasing the loss of the bridgeless totem pole PFC circuit. Summary of the Invention

[0005] An embodiment of the present application provides a computing device, which includes a power supply module. The power supply module can match a compensated negative current signal with an actual negative current signal requirement, thereby reducing the loss of a bridgeless totem pole PFC circuit under zero voltage turn-on conditions.

[0006] In a first aspect, an embodiment of the present application provides a computing device, comprising a power module, the power module comprising a control circuit and a bridgeless totem pole power factor correction (PFC) circuit, the bridgeless totem pole PFC circuit comprising a main switch tube and a freewheeling tube, the control circuit being connected to the freewheeling tube and the main switch tube; the control circuit being configured to:

[0007] Monitor the circuit parameters of the bridgeless totem pole PFC circuit; the bridgeless totem pole PFC circuit includes inductors and parasitic capacitors; circuit parameters include delay time, input voltage signal, output voltage signal, inductance value of the inductor, and capacitance value of the parasitic capacitor; delay time includes circuit delay time and delay time corresponding to the freewheeling diode;

[0008] According to the circuit parameters, the preset table is consulted to determine the dead zone duration and the negative current threshold; the preset table indicates the corresponding relationship between the circuit parameters and the dead zone duration and the negative current threshold;

[0009] According to the negative current threshold, the freewheeling tube is controlled to be disconnected;

[0010] Control the main switch tube to turn on under zero - voltage conditions according to the dead - time duration.

[0011] In this solution, the computing device may include a power supply module. The power supply module may include a control circuit and a bridgeless totem - pole PFC circuit. The bridgeless totem - pole PFC circuit includes a main switch tube and a free - wheeling diode. The control circuit may be connected to the main switch tube and the free - wheeling diode. The control circuit can monitor the circuit parameters of the bridgeless totem - pole PFC circuit, and according to the circuit parameters, query a preset table to determine the dead - time duration and the negative - current threshold. Among them, the preset table indicates the corresponding relationship between the circuit parameters, the dead - time duration, and the negative - current threshold. The control circuit can control the free - wheeling diode to turn off according to the negative - current threshold, and after an interval of the dead - time duration, control the main switch tube to turn on. Since within the dead - time duration, the negative - current signal can completely drain the charge in the parasitic capacitance of the main switch tube, the main switch tube is turned on under zero - voltage conditions. That is to say, through the above method, the compensated negative - current signal can be matched with the actual negative - current signal requirement, so as to reduce the power consumption of the bridgeless totem - pole PFC circuit while realizing the main switch tube turning on under zero - voltage conditions. In addition, by pre - constructing a preset table indicating the corresponding relationship between the circuit parameters, the dead - time duration, and the negative - current threshold, the control circuit can quickly determine the negative - current threshold and the dead - time duration corresponding to the circuit parameters by looking up the table, reducing the computing power requirement for the control circuit, and thus reducing the cost of the control circuit. In addition, by dynamically determining the negative - current threshold based on the monitored circuit parameters, the effective value of the negative - current signal of the inductor is reduced, and the absolute value of the minimum value of the negative - current signal of the inductor is reduced, thereby reducing the saturation requirement for the inductor and thus reducing the cost of the inductor.

[0012] In one implementation, the bridgeless totem - pole PFC circuit includes a current - sensing resistor and an inductor; the control circuit includes a controller, a comparator circuit, and a differential - amplifier circuit;

[0013] The first end of the comparator circuit is connected to the first end of the differential - amplifier circuit;

[0014] The second end of the comparator is respectively connected to the current - sensing resistor and the inductor;

[0015] The third end of the comparator is connected to the first end of the controller;

[0016] The second end of the controller is connected to the main switch tube, the third end of the controller is connected to the free - wheeling diode, the fourth end of the controller is connected to the second end of the differential - amplifier circuit, and the fifth end of the controller is connected to the third end of the differential - amplifier circuit.

[0017] In this solution, the bridgeless totem-pole PFC circuit may include a current sensing resistor and an inductor. The control circuit includes a controller, a comparison circuit, and a differential amplifier circuit. Among them, the first end of the comparison circuit is connected to the first end of the differential amplifier circuit; the second end of the comparison circuit is respectively connected to the current sensing resistor and the inductor; the third end of the comparison circuit is connected to the first end of the controller; the second end of the controller is connected to the main switch tube, the third end of the controller is connected to the freewheeling diode, the fourth end of the controller is connected to the second end of the differential amplifier circuit, and the fifth end of the controller is connected to the third end of the differential amplifier circuit. Based on this structure, the controller of the control circuit can control the freewheeling diode to turn off according to the negative current threshold, and control the main switch tube to turn on under the zero-voltage condition according to the dead time duration, so that the compensated negative current signal can match the actual negative current signal requirement, thereby reducing the loss of the bridgeless totem-pole PFC circuit.

[0018] In one implementation, the differential amplifier circuit includes an operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor;

[0019] The first end of the operational amplifier is respectively connected to the first end of the first resistor and the first end of the second resistor;

[0020] The second end of the operational amplifier is respectively connected to the first end of the third resistor and the first end of the fourth resistor;

[0021] The second end of the first resistor is connected to the fourth end of the controller, and the second end of the second resistor is connected to the third end of the operational amplifier;

[0022] The second end of the third resistor is connected to the fifth end of the controller, and the second end of the fourth resistor is connected to the ground;

[0023] The third end of the operational amplifier is connected to the first end of the comparison circuit.

[0024] In this solution, the differential amplifier circuit includes an operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor. The first terminal of the operational amplifier is respectively connected to the first terminal of the first resistor and the first terminal of the second resistor. The second terminal of the operational amplifier is respectively connected to the first terminal of the third resistor and the first terminal of the fourth resistor. The second terminal of the first resistor is connected to the fourth terminal of the controller, and the second terminal of the second resistor is connected to the third terminal of the operational amplifier. The second terminal of the third resistor is connected to the fifth terminal of the controller, and the second terminal of the fourth resistor is connected to the ground. The third terminal of the operational amplifier is connected to the first terminal of the comparison circuit. Based on this structure, the differential amplifier circuit can perform differential amplification processing based on the first signal (obtained after converting the negative current threshold (digital signal)) and the reference signal to obtain a differential amplification signal, so that the comparison circuit can output a level signal based on the differential amplification signal and the negative current signal, and further enable the controller to control the freewheeling diode to turn off when the level signal output by the comparison circuit flips. That is to say, through the above structure, the control circuit can accurately control the freewheeling diode to turn off based on the negative current threshold.

[0025] In one implementation, the fifth terminal of the controller is a digital-to-analog conversion terminal.

[0026] In this solution, the fifth terminal of the controller can be a digital-to-analog conversion terminal so that the reference signal sent by the controller to the differential amplifier circuit can be an analog signal.

[0027] In one implementation, when the fifth terminal of the controller is not a digital-to-analog conversion terminal, the differential amplifier circuit further includes a filter capacitor. The first terminal of the filter capacitor is connected to the first terminal of the fourth resistor, and the second terminal of the filter capacitor is connected to the second terminal of the fourth resistor.

[0028] In this solution, when the fifth terminal of the controller is not a digital-to-analog conversion terminal, the differential amplifier circuit further includes a filter capacitor. The first terminal of the filter capacitor is connected to the first terminal of the fourth resistor, and the second terminal of the filter capacitor is connected to the second terminal of the fourth resistor. Through this structure, the filter capacitor can be used to filter the reference signal to obtain an analog signal. That is to say, through this structure, the differential amplifier circuit can still obtain an analog signal when the digital-to-analog conversion terminal of the controller is insufficient.

[0029] In one implementation, the control circuit is specifically used for:

[0030] Determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition according to the circuit parameters;

[0031] If so, query the preset table to determine the dead time and negative current threshold corresponding to the circuit parameters;

[0032] Otherwise, determine that the negative current threshold is zero, query the preset table, and determine the dead time corresponding to the circuit parameters.

[0033] In this solution, the control circuit can determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition based on the circuit parameters. When the bridgeless totem-pole PFC circuit meets the negative current compensation condition, the control circuit can determine the dead time and the negative current threshold by querying the preset table. When the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition, the control circuit determines that the negative current threshold is zero, queries the preset table, and determines the dead time corresponding to the circuit parameters. By the above method, the accuracy and efficiency of determining the dead time and the negative current threshold are improved.

[0034] In one implementation, the parasitic capacitance is the parasitic capacitance of the main switch.

[0035] In this solution, by setting the circuit parameters including the capacitance value of the parasitic capacitance, and the parasitic capacitance is the parasitic capacitance of the main switch, the dead time and the negative current threshold determined based on the circuit parameters match the actual situation of the main switch, improving the accuracy of the dead time and the negative current threshold determined by the control circuit.

[0036] In one implementation, the control circuit is specifically used for:

[0037] Determine whether the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio;

[0038] If so, determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition;

[0039] If not, determine that the bridgeless totem-pole PFC circuit meets the negative current compensation condition.

[0040] In this solution, when the ratio of the input voltage signal to the output voltage signal is less than or equal to the preset ratio, the resonant current signal generated by the resonance of the inductor with the parasitic capacitance of the main switch and the parasitic capacitance of the freewheeling diode can drain all the charges in the parasitic capacitance of the main switch, so that the main switch can be turned on under zero voltage conditions without compensating the negative current signal. When the ratio of the input voltage signal to the output voltage signal is greater than the preset ratio, the resonant current signal cannot drain all the charges in the parasitic capacitance of the main switch. Therefore, a method of compensating the negative current signal is required so that the compensated negative current signal can drain all the charges in the parasitic capacitance of the main switch, thereby realizing the main switch to be turned on under zero voltage conditions. By the above method, it is possible to accurately determine whether negative current signal compensation is required, thereby reducing the loss of the bridgeless totem-pole PFC circuit.

[0041] In one implementation, the control circuit is further configured to:

[0042] Determine whether the input voltage signal is less than or equal to a preset input voltage signal;

[0043] If so, determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition.

[0044] In this solution, when the input voltage signal is less than or equal to the preset input voltage signal, the input voltage signal is much smaller than the output voltage signal, and the resonant current signal can drain all the charge in the parasitic capacitance of the main switch tube. Thus, it is possible to turn on the main switch tube under zero voltage condition without compensating the negative current signal, reducing the loss of the bridgeless totem-pole PFC circuit.

[0045] In one implementation, the control circuit is specifically configured to:

[0046] Based on a preset look-up table frequency, query a preset table according to circuit parameters to determine the dead time duration and the negative current threshold.

[0047] In this solution, the control circuit can query a preset table according to circuit parameters based on a preset look-up table frequency to determine the dead time duration and the negative current threshold. By the above method of looking up the table based on the preset look-up table frequency, the computing power requirement of the control circuit can be reduced.

[0048] In a second aspect, an embodiment of the present application provides a control method applied to a control circuit; the computing device includes a power supply module, the power supply module includes a control circuit and a bridgeless totem-pole power factor correction (PFC) circuit, the bridgeless totem-pole PFC circuit includes a main switch tube and a freewheeling diode, and the control circuit is connected to the freewheeling diode and the main switch tube; the method includes:

[0049] Monitor the circuit parameters of the bridgeless totem-pole PFC circuit; the bridgeless totem-pole PFC circuit includes an inductor and a parasitic capacitance; the circuit parameters include a delay duration, an input voltage signal, an output voltage signal, the inductance value of the inductor, and the capacitance value of the parasitic capacitance; the delay duration includes a circuit delay duration and a delay duration corresponding to the freewheeling diode;

[0050] According to the circuit parameters, query a preset table to determine the dead time duration and the negative current threshold; the preset table indicates the corresponding relationship between the circuit parameters and the dead time duration and the negative current threshold;

[0051] Control the freewheeling diode to turn off according to the negative current threshold;

[0052] Control the main switch tube to turn on under zero voltage condition according to the dead time duration.

[0053] The control method provided by the embodiment of the present application can be applied to the control circuit in the computing device in the above embodiment, and its beneficial effects are similar and will not be elaborated here.

[0054] In one implementation, the bridgeless totem-pole PFC circuit includes a current sensing resistor and an inductor; the control circuit includes a controller, a comparison circuit, and a differential amplifier circuit;

[0055] The first end of the comparison circuit is connected to the first end of the differential amplifier circuit;

[0056] The second end of the comparator is respectively connected to the current sensing resistor and the inductor;

[0057] The third end of the comparator is connected to the first end of the controller;

[0058] The second end of the controller is connected to the main switch transistor, the third end of the controller is connected to the freewheeling diode, the fourth end of the controller is connected to the second end of the differential amplifier circuit, and the fifth end of the controller is connected to the third end of the differential amplifier circuit.

[0059] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar, so details are not described herein again.

[0060] In one implementation, the differential amplifier circuit includes an operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor;

[0061] The first end of the operational amplifier is respectively connected to the first end of the first resistor and the first end of the second resistor;

[0062] The second end of the operational amplifier is respectively connected to the first end of the third resistor and the first end of the fourth resistor;

[0063] The second end of the first resistor is connected to the fourth end of the controller, and the second end of the second resistor is connected to the third end of the operational amplifier;

[0064] The second end of the third resistor is connected to the fifth end of the controller, and the second end of the fourth resistor is connected to the ground;

[0065] The third end of the operational amplifier is connected to the first end of the comparison circuit.

[0066] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar, so details are not described herein again.

[0067] In one implementation, the fifth end of the controller is a digital-to-analog conversion terminal.

[0068] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar, so details are not described herein again.

[0069] In one implementation, when the fifth terminal of the controller is not a digital-to-analog conversion terminal, the differential amplifier circuit further includes a filter capacitor. The first terminal of the filter capacitor is connected to the first terminal of the fourth resistor, and the second terminal of the filter capacitor is connected to the second terminal of the fourth resistor.

[0070] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar and will not be elaborated here.

[0071] In one implementation, according to the circuit parameters, querying a preset table to determine the dead time and the negative current threshold includes:

[0072] According to the circuit parameters, determining whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition;

[0073] If so, query the preset table to determine the dead time and the negative current threshold corresponding to the circuit parameters;

[0074] If not, determine that the negative current threshold is zero, and query the preset table to determine the dead time corresponding to the circuit parameters.

[0075] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar and will not be elaborated here.

[0076] In one implementation, the parasitic capacitance is the parasitic capacitance of the main switching transistor.

[0077] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar and will not be elaborated here.

[0078] In one implementation, according to the circuit parameters, determining whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition includes:

[0079] Determining whether the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio;

[0080] If so, determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition;

[0081] If not, determine that the bridgeless totem-pole PFC circuit meets the negative current compensation condition.

[0082] The control method provided by the embodiments of the present application can be applied to the control circuit in the computing device in the above embodiments, and the beneficial effects are similar and will not be elaborated here.

[0083] In one implementation, the method further includes:

[0084] Determining whether the input voltage signal is less than or equal to a preset input voltage signal;

[0085] If so, it is determined that the bridgeless totem pole PFC circuit does not meet the negative current compensation condition.

[0086] The control method provided in the embodiment of the present application can be applied to the control circuit in the computing device in the above embodiment, and its beneficial effects are similar, which will not be described again here.

[0087] In one implementation, according to the circuit parameters, a preset table is searched to determine the dead zone duration and the negative current threshold, including:

[0088] Based on the preset table lookup frequency and according to the circuit parameters, the preset table is queried to determine the dead zone duration and the negative current threshold.

[0089] The control method provided in the embodiment of the present application can be applied to the control circuit in the computing device in the above embodiment, and its beneficial effects are similar, which will not be described again here.

[0090] In a third aspect, an embodiment of the present application provides a computer-readable storage medium having computer-executable instructions stored thereon; when the computer-executable instructions are executed by a control circuit, they are used to implement the control method of the second aspect.

[0091] In a fourth aspect, an embodiment of the present application provides a computer program product, which includes a computer program. When the computer program is executed by a control circuit, it is used to execute the control method of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0093] Figure 1 A schematic diagram of the structure of a power module provided in an embodiment of the present application;

[0094] Figure 2 A schematic diagram of the working principle of a bridgeless totem pole PFC circuit provided in an embodiment of the present application;

[0095] Figure 3 A schematic diagram of signal changes provided in an embodiment of the present application;

[0096] Figure 4 A schematic diagram of the working principle of another bridgeless totem pole PFC circuit provided in an embodiment of the present application;

[0097] Figure 5 Schematic diagram of the current signal of an inductor provided by an embodiment of the present application;

[0098] Figure 6 Structural schematic diagram of a control circuit provided by an embodiment of the present application Figure 1 ;

[0099] Figure 7 Structural schematic diagram of a control circuit provided by an embodiment of the present application Figure 2 ;

[0100] Figure 8 Structural schematic diagram of a control circuit provided by an embodiment of the present application Figure 3 ;

[0101] Figure 9 Schematic diagram of a PWM signal provided by an embodiment of the present application;

[0102] Figure 10 Flow schematic diagram of a control method provided by an embodiment of the present application Figure 1 ;

[0103] Figure 11 Flow schematic diagram of a control method provided by an embodiment of the present application Figure 2 . Detailed implementation manners

[0104] Here, the exemplary embodiments will be described in detail, and the examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the embodiments of the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0105] It should be noted that, in the embodiments of the present application, the term "at least one" means one or more, and "a plurality" means two or more.

[0106] An embodiment of the present application provides a computing device, which includes a power supply module. The power supply module includes a control circuit and a bridgeless totem-pole power factor correction (PFC) circuit. The bridgeless totem-pole PFC circuit includes a main switch transistor and a freewheeling diode. The control circuit can be connected to the main switch transistor and the freewheeling diode. The control circuit can monitor the circuit parameters of the bridgeless totem-pole PFC circuit, and query a preset table (indicating the correspondence between the circuit parameters, the dead-time duration, and the negative current threshold) according to the circuit parameters, and determine the dead-time duration and the negative current threshold. The control circuit can control the freewheeling diode to turn off according to the negative current threshold. The control circuit can control the main switch transistor to turn on under zero-voltage conditions according to the dead-time duration.

[0107] By determining the dead-time duration and the negative current threshold based on the monitored circuit parameters, and then controlling the freewheeling diode to turn off based on the negative current threshold and controlling the main switch transistor to turn on under zero-voltage conditions according to the dead-time duration, the compensated negative current signal can be matched with the actual negative current signal requirement, thereby reducing the loss of the bridgeless totem-pole PFC circuit under zero-voltage turn-on conditions.

[0108] Figure 1 It is a schematic structural diagram of a power supply module provided by an embodiment of the present application.

[0109] As Figure 1 shown, the power supply module 10 may include a control circuit 11 and a bridgeless totem-pole PFC circuit 12. The power supply module 10 may be the power supply module in a computing device. The computing device may be a server. The power supply module supplies power to components in the server, such as a CPU, a baseboard management controller, a memory, a hard disk, etc. The server may be a whole rack server, an AI server, etc.

[0110] The bridgeless totem-pole PFC circuit 12 may include a main switch transistor and a freewheeling diode. The control circuit 11 is connected to the freewheeling diode ( Figure 1 the connection relationship is not shown), and in addition, the control circuit may also be connected to the main switch transistor ( Figure 1 the connection relationship is not shown). The control circuit 11 can be used to control the turn-on and turn-off of the main switch transistor and the freewheeling diode.

[0111] In addition, the bridgeless totem-pole PFC circuit 12 may further include an AC power supply 121, a current detection resistor R0, an inductor L, the parasitic capacitance of the main switch transistor, the parasitic capacitance of the freewheeling diode, a load 122, a capacitor C1, and a first switching device and a second switching device. It should be noted that the control circuit 11 may also be connected to the current detection resistor R0 and the inductor L. The control circuit 11 may also be connected to the first switching device of the bridgeless totem-pole PFC circuit 12 (exemplarily, Figure 1shows that the first switching device is a MOS transistor - Q1), and the second switching device (exemplarily, Figure 1 shows that the second switching device is a MOS transistor - Q2) is connected ( Figure 1 the connection relationship is not shown). The control circuit 11 can be used to control the turning on and off of the first switching device and the second switching device.

[0112] It should be noted that the main switching transistor and the freewheeling diode can be metal oxide semiconductor field effect transistors (Metal Oxide Semiconductor Field Effect Transistor, abbreviated as MOS transistor). It should also be noted that during the period when N (neutral line) is positive and L (live line) is negative, Q4 is the main switching transistor and Q3 is the freewheeling diode. Correspondingly, the parasitic capacitance of the main switching transistor is C4, and the parasitic capacitance of the freewheeling diode is C3; during the period when L (live line) is positive and N (neutral line) is negative, Q3 is the main switching transistor and Q4 is the freewheeling diode. Correspondingly, the parasitic capacitance of the main switching transistor is C3, and the parasitic capacitance of the freewheeling diode is C4. It should also be noted that the main switching transistor is the core component of the bridgeless totem-pole PFC circuit 12, which is used to adjust the waveform of the current signal through high-frequency switching actions, so that the waveform of the current signal can be synchronized with the waveform of the voltage signal, reducing the phase difference between the current signal and the voltage signal, thereby achieving power factor correction. The freewheeling diode is used to provide a low-loss (low impedance) freewheeling path for the current signal of the inductor L, so that the current signal of the inductor can continue to flow. That is to say, the freewheeling diode can provide a smooth energy release path, so that the energy of the inductor can be released, thus avoiding the situation where the energy of the inductor L cannot be released, resulting in voltage spikes.

[0113] The first switching device and the second switching device can be MOS transistors or diodes, and the embodiments of the present application do not limit this. Exemplarily, Figure 1 shows that the first switching transistor device is a MOS transistor - Q1, and the second switching device is a MOS transistor - Q2.

[0114] Next, in combination with Figure 2 and Figure 3 , the working principle of the bridgeless totem-pole PFC circuit during the period when N (neutral line) is positive and L (live line) is negative will be described.

[0115] Figure 2 is a schematic diagram of the working principle of a bridgeless totem-pole PFC circuit provided by an embodiment of the present application.

[0116] Figure 3 is a schematic diagram of signal changes provided by an embodiment of the present application.

[0117] As Figure 2As shown, during the period when N (neutral line) is positive and L (live wire) is negative, Q4 is the main switching transistor and Q3 is the freewheeling diode. Additionally, it should be noted that, by way of example, Figure 2 it is shown that the first switching device is a MOS transistor - Q1, and the second switching device is a MOS transistor - Q2.

[0118] In Figure 2 (a), the control circuit 11 can control Q2 and Q4 (the main switching transistor) to turn on, and the input voltage signal (Vin) of the AC power supply 121 charges the inductor L. The current path is the N terminal of the AC power supply 121 → the current detection resistor R0 → the inductor L → Q4 → Q2 → the L terminal of the AC power supply 121. During this process, as Figure 3 shown, the current signal of the inductor L gradually rises. Additionally, it should be noted that, as Figure 3 shown, during this process, the drive signal of Q4 (the main switching transistor) is not zero so that Q4 conducts (turns on); the drive signal of Q3 (the freewheeling diode) is zero so that Q3 turns off; the drain-source voltage signal (Vds) of Q4 is zero.

[0119] In Figure 2 (b), the control circuit 11 can control Q4 (the main switching transistor) to turn off and control Q3 (the freewheeling diode) to turn on. At this time, Q2 and Q3 are in the on state. The current path is the N terminal of the AC power supply 121 → the current detection resistor R0 → the inductor L → Q3 → the load 122 → Q2 → the L terminal of the AC power supply 121. During this process, the inductor L can supply power to the load 122 through Q3 (the freewheeling diode). As Figure 3 shown, during the process of the inductor L supplying power to the load 122 through Q3, the current signal of the inductor L continues to decrease. Additionally, it should be noted that during this process, the drive signal of Q3 (the freewheeling diode) is not zero so that Q3 conducts (turns on); the drive signal of Q4 (the main switching transistor) is zero so that Q4 turns off. Additionally, it should also be noted that after Q4 (the main switching transistor) turns off, the current signal of the inductor L can freewheel through Q3 (the freewheeling diode), the parasitic capacitor C4 of Q4 (the main switching transistor) starts to charge, and the drain-source voltage signal (Vds) of Q4 (the main switching transistor) linearly rises and then remains at a high level state.

[0120] In Figure 2 (c), Q2 and Q3 are in the on state. During the process of the current signal of the inductor L continuing to decrease, a current reverse injection occurs. During the current reverse injection process, the current path is the L terminal of the AC power supply 121 → Q2 → the load 122 → Q3 → the inductor L → the current detection resistor R0 → the N terminal of the AC power supply 121. As Figure 3 shown, during this process, the reverse injection current signal of the inductor L decreases with a negative slope, forming a larger negative current signal.

[0121] It should be noted that current reverse injection refers to the conversion of a current signal from a positive current signal to a negative current signal. It should also be noted that when the inductor L supplies power to the load 122 through Q3 (freewheeling diode), the current signal is a positive current signal (forward current signal). Based on the forward current signal, a current signal in the opposite direction to the forward current signal is a negative current signal.

[0122] It should further be noted that the reason for current reverse injection is as follows: during the process of the current signal of the inductor L continuously decreasing, there will be a situation where the voltage signal across the load 122 is greater than the input voltage signal. When the voltage signal across the load 122 is greater than the input voltage signal, the current signal can flow from the load 122 to the inductor L, thereby forming current reverse injection.

[0123] In Figure 2 (d), when the control circuit 11 detects that the negative current signal of the inductor L reaches the negative current threshold, it controls Q3 (freewheeling diode) to turn off. It should be noted that as Figure 3 shown, after the control circuit 11 controls Q3 to turn off, the current path is from the L terminal of the AC power supply 121 → Q2 → the parasitic capacitance of Q4 → inductor L → current detection resistor R0 → the N terminal of the AC power supply 121. During this process, the negative current signal of the inductor L can extract the charge in the parasitic capacitance C4 of Q4, reducing the charge quantity of the parasitic capacitance of Q4, and thus reducing the voltage across the parasitic capacitance C4 of Q4. Additionally, it should be noted that during this process, the inductor L resonates with the parasitic capacitance C3 of Q3 and the parasitic capacitance C4 of Q4, generating a resonant current signal, which can be used as part of the negative current signal to extract the charge in the parasitic capacitance C4 of Q4. As Figure 3 shown, during the process of charge extraction, the drain-source voltage signal (Vds) of Q4 (main switch) linearly decreases.

[0124] The control circuit 11 can control Q4 (main switch) to turn on based on the dead time. Since all the charge in the parasitic capacitance of Q4 is extracted during the dead time, Q4 (main switch) is turned on under zero voltage conditions. It should be noted that the dead time is used to determine the moment to turn on Q4 (main switch). In other words, after the moment of controlling Q3 (freewheeling diode) to turn off, the control circuit 11 controls Q4 (main switch) to turn on after an interval of the dead time.

[0125] Next, in combination with Figure 4 , the operating principle of the bridgeless totem-pole PFC circuit will be described during the period when L (live wire) is positive and N (neutral wire) is negative.

[0126] Figure 4Schematic diagram of the working principle of another bridge-less totem pole PFC circuit provided by the embodiments of the present application.

[0127] As Figure 4 shown, during the period when L (live wire) is positive and N (neutral wire) is negative, Q3 is the main switch tube and Q4 is the freewheeling diode. In addition, it should be noted that, by way of example, Figure 4 it is shown that the first switch tube is a MOS tube - Q1, and the second switch tube is a MOS tube - Q2.

[0128] During Figure 4 (a), the control circuit 11 can control Q1 and Q3 (main switch tubes) to turn on. The current path is the L terminal of the AC power supply 121 → Q1 → Q3 → inductor L → current detection resistor R0 → the N terminal of the AC power supply 121. The input voltage signal (Vin) of the AC power supply 121 charges the inductor L.

[0129] During Figure 4 (b), the control circuit 11 can control Q3 (main switch tube) to turn off and control Q4 (freewheeling diode) to turn on. At this time, Q1 and Q4 are in the on state. The current path is the L terminal of the AC power supply 121 → Q1 → load 122 → Q4 → inductor L → current detection resistor R0 → the N terminal of the AC power supply. During this process, the inductor L can supply power to the load 122 through Q4 (freewheeling diode). During the process of the inductor L supplying power to the load 122 through Q4, the current signal of the inductor L is continuously decreasing.

[0130] During Figure 4 (c), Q1 and Q4 are in the on state. During the process of the current signal of the inductor L continuously decreasing, a current reverse injection situation occurs. The current path is the N terminal of the AC power supply 121 → current detection resistor R0 → inductor L → Q4 → load 122 → Q1 → the L terminal of the AC power supply 121. During this process, the reverse injection current signal of the inductor L decreases with a negative slope, forming a larger negative current signal. It should be noted that, taking the current signal when the inductor L supplies power to the load 122 through Q4 (freewheeling diode) as the reference, the current signal in the opposite direction to the positive current signal is the negative current signal.

[0131] During Figure 4In (d), when the control circuit 11 detects that the negative current signal of the inductor L reaches the negative current threshold, it controls Q4 (freewheeling diode) to turn off. After the control circuit 11 controls Q4 to turn off, the current path is the N terminal of the AC power supply 121 → the current detection resistor R0 → the inductor L → Q3 → Q1 → the L terminal of the AC power supply 121. During this process, the negative current signal of the inductor L can extract the charge in the parasitic capacitance of Q3 (main switch). In addition, it should be noted that the inductor L resonates with the parasitic capacitance C3 of Q3 and the parasitic capacitance C4 of Q4, and a resonant current signal can be generated. The resonant current signal can be used as part of the negative current signal to extract the charge in the parasitic capacitance C3 of Q3 (main switch).

[0132] The control circuit 11 can control Q3 (main switch) to turn on based on the dead time duration. Since the charge in the parasitic capacitance C3 of Q3 is completely extracted during the dead time duration, Q3 (main switch) turns on under zero voltage conditions.

[0133] Based on the above, it can be seen that the control circuit 11 needs to control the freewheeling diode to turn off according to the negative current threshold, and control the main switch to turn on under zero voltage conditions according to the dead time duration.

[0134] Next, the process in which the control circuit controls the freewheeling diode to turn off according to the negative current threshold and controls the main switch to turn on under zero voltage conditions according to the dead time duration will be described.

[0135] In one implementation

[0136] The control circuit 11 can monitor the circuit parameters of the bridgeless totem-pole PFC circuit 12. In one implementation, the circuit parameters may include the delay duration, the input voltage signal, the output voltage signal, the inductance value of the inductor L, and the capacitance value of the parasitic capacitance. Among them, the delay duration includes the circuit delay duration and the delay duration corresponding to the freewheeling diode. It should be noted that the circuit delay duration refers to the duration required for the control signal (turn-on signal or turn-off signal) sent by the control circuit 11 to reach the freewheeling diode (the duration required for the control signal to be transmitted in the circuit); the delay duration corresponding to the freewheeling diode refers to the duration required for the freewheeling diode to turn on or off based on the control signal. By setting the circuit parameters to include the delay duration in the above manner, the dead time duration and the negative current threshold determined based on the circuit parameters match the actual situation of the freewheeling diode, improving the accuracy of the dead time duration and the negative current threshold determined by the control circuit, so that the method of the embodiments of the present application can be applied to various types of freewheeling diodes (for example, the freewheeling diode can be a MOS transistor based on silicon material).

[0137] The control circuit 11 can query a preset table according to the monitored circuit parameters to determine the dead time duration and the negative current threshold. In one implementation, the control circuit 11 can query the preset table based on a preset table lookup frequency according to the monitored circuit parameters to determine the dead time duration and the negative current threshold. By the above method of looking up the table based on the preset table lookup frequency, the computing power requirement of the control circuit 11 can be reduced. It should be noted that the preset table indicates the correspondence between the circuit parameters and the dead time duration and the negative current threshold. It should also be noted that the preset table is pre-constructed for the control circuit 11.

[0138] The control circuit 11 can control the freewheeling diode to turn off according to the negative current threshold, and control the main switch to turn on under the zero voltage condition according to the dead time duration.

[0139] It should be noted that when the negative current signal of the inductor L reaches zero and does not reach the negative current threshold, that is, during the process when the freewheeling diode is not turned off (the freewheeling diode is delayed in turning off), the reverse injection current signal of the inductor L can decrease with a negative slope to form a negative current signal, thereby realizing the compensation of the negative current signal.

[0140] After the control circuit 11 controls the freewheeling diode to turn off according to the negative current threshold, the negative current signal of the inductor L can extract the charge in the parasitic capacitance of the main switch. In addition, it should be noted that the inductor L resonates with the parasitic capacitances of the main switch and the freewheeling diode, and a resonant current signal can be generated. The resonant current signal can be used as part of the negative current signal to extract the charge in the parasitic capacitance of the main switch. When the control circuit 11 controls the main switch to turn on according to the dead time duration, since the charge in the parasitic capacitance of the main switch is completely extracted during the dead time duration, the main switch is turned on under the zero voltage condition.

[0141] By the above method of dynamically determining the dead time duration and the negative current threshold based on the monitored circuit parameters, the negative current signal can be dynamically compensated, so that the compensated negative current signal matches the actual negative current signal requirement, and the charge in the parasitic capacitance of the main switch can be emptied during the dead time duration. Figure 5 This is a schematic diagram of the current signal of an inductor provided by an embodiment of the present application. As Figure 5 shown, the valley value of the current signal of the inductor is not a straight line, but a dynamically changing curve. Compared with the method in the related art of compensating the negative current signal based on a fixed negative current threshold, which results in relatively large circuit losses, the method of the embodiment of the present application reduces the circuit losses.

[0142] Next, the process of the control circuit 11 pre-constructing the preset table will be described.

[0143] In one implementation,

[0144] The control circuit can calculate the negative current threshold and dead time corresponding to the circuit parameters based on the following formula.

[0145]

[0146] Tdelay = T mosdelay + T icdelay

[0147]

[0148] Wherein, Icomp refers to the negative current threshold; L is the inductance value of the inductor L, Coss is the capacitance value of the parasitic capacitance of the main switch tube, V o is the output voltage signal (the voltage signal across the load 122), V in is the input voltage signal (the voltage signal across the AC power supply 121), Zc is the characteristic impedance, Tdelay is the delay time, T mosdelay is the delay time corresponding to the freewheeling diode, T icdelay is the circuit delay time, T dead is the dead time.

[0149] After calculating the negative current threshold and dead time corresponding to different circuit parameters, the control circuit 11 can generate a preset table based on the different circuit parameters, as well as the negative current threshold and dead time corresponding to the circuit parameters. Among them, the preset table indicates the corresponding relationship between the circuit parameters, the dead time, and the negative current threshold.

[0150] It should be noted that for a set of circuit parameters, the control circuit 11 can calculate a negative current threshold and a dead time corresponding to the set of circuit parameters based on the set of circuit parameters. The control circuit 11 can generate a preset table based on multiple sets of circuit parameters, as well as the negative current threshold and dead time corresponding to each set of circuit parameters in the multiple sets of circuit parameters.

[0151] It should be noted that the negative current threshold is used to determine the moment to turn off the freewheeling diode. In other words, at the moment when the negative current signal reaches the negative current threshold, the control circuit 11 can control the freewheeling diode to turn off.

[0152] The dead time is used to determine the moment to turn on the main switch tube. In other words, after the moment of controlling the freewheeling diode to turn off, with an interval of the dead time, the control circuit 11 can control the main switch tube to turn on.

[0153] Advantages of this embodiment: In this embodiment, the computing device may include a power supply module. The power supply module may include a control circuit and a bridgeless totem-pole PFC circuit. The bridgeless totem-pole PFC circuit includes a main switch transistor and a freewheeling diode, and the control circuit may be connected to the freewheeling diode. The control circuit may monitor the circuit parameters of the bridgeless totem-pole PFC circuit, and based on the circuit parameters, query a preset table to determine the dead-time duration and the negative current threshold. Among them, the preset table indicates the correspondence between the circuit parameters and the dead-time duration and the negative current threshold. The control circuit may control the freewheeling diode to turn off according to the negative current threshold, and control the main switch transistor to turn on under zero-voltage conditions according to the dead-time duration. By the above method of determining the dead-time duration and the negative current threshold based on the monitored circuit parameters, the compensated negative current signal can be matched with the actual negative current signal demand. Among them, the compensated negative current signal includes a resonant current signal and a negative current signal (negative current signal generated by delaying the turn-off of the freewheeling diode) that matches the negative current threshold. On the one hand, it can make the compensated negative current signal extract all the charges in the parasitic capacitance of the main switch transistor; on the other hand, it can avoid the problem that the compensated negative current signal is too large, resulting in excessive loss of the main switch transistor. In addition, by pre-constructing a preset table indicating the correspondence between the circuit parameters and the dead-time duration and the negative current threshold, the control circuit can quickly determine the negative current threshold and the dead-time duration corresponding to the circuit parameters by looking up the table, reducing the computing power requirement for the control circuit, and thus reducing the cost of the control circuit. In addition, by dynamically determining the dead-time duration and the negative current threshold based on the monitored circuit parameters, the effective value of the negative current signal of the inductor is reduced, and the absolute value of the minimum value of the negative current signal of the inductor is reduced, thereby reducing the saturation requirement for the inductor and reducing the cost of the inductor.

[0154] Next, through Embodiment 2, the process of the control circuit 11 querying the preset table according to the circuit parameters to determine the dead-time duration and the negative current threshold will be described.

[0155] In one implementation,

[0156] The control circuit 11 may determine whether the bridgeless totem-pole PFC circuit 12 meets the negative current compensation condition according to the circuit parameters.

[0157] If so, the control circuit 11 may query the preset table to determine the dead-time duration and the negative current threshold corresponding to the circuit parameters.

[0158] If not, the control circuit 11 may determine that the negative current threshold is zero and query the preset table to determine the dead-time duration corresponding to the circuit parameters.

[0159] Next, the process of the control circuit 11 determining whether the bridgeless totem-pole PFC circuit 12 meets the negative current compensation condition according to the circuit parameters will be described.

[0160] In one implementation,

[0161] The circuit parameters may include an input voltage signal and an output voltage signal.

[0162] The control circuit 11 may determine whether the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio. In one implementation, the preset ratio may be 0.5. That is, the control circuit may determine whether the input voltage signal is less than or equal to half of the output voltage signal.

[0163] If so, the control circuit 11 may determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition.

[0164] If not, the control circuit 11 may determine that the bridgeless totem-pole PFC circuit meets the current compensation condition.

[0165] Next, the reason why the control circuit can determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition when the ratio of the input voltage signal to the output voltage signal is less than or equal to the preset ratio will be described.

[0166] The inductor L can resonate with the parasitic capacitance of the main switch tube and the parasitic capacitance of the freewheeling diode to generate a resonant current signal. The resonant current signal can extract the charge of the parasitic capacitance of the main switch tube, causing the voltage signal (Vds) between the drain and source of the main switch tube to drop.

[0167] Taking the main switch tube as Q3, the parasitic capacitance of the main switch tube as C3, the freewheeling diode as Q4, and the parasitic capacitance of the freewheeling diode as C4, and the capacitance values of C3 and C4 are both Coss as an example, the voltage signal (Vds) between the drain and source of the main switch tube satisfies the following formula:

[0168] Vds = V o coswt + V in (1 - coswt)

[0169]

[0170] Based on the above formula, it can be seen that the valley value of the Vds resonance is 2V in - V oThat is to say, when the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio (0.5), the resonant current signal can completely drain the charge in the parasitic capacitance of the main switch tube, so that the main switch tube can be turned on under the zero-voltage condition without compensating the negative current signal. When the ratio of the input voltage signal to the output voltage signal is greater than the preset ratio (0.5), the resonant current signal cannot completely drain the charge in the parasitic capacitance of the main switch tube. Therefore, a method of compensating the negative current signal is required so that the compensated negative current signal can completely drain the charge in the parasitic capacitance of the main switch tube, thereby realizing the turn-on of the main switch tube under the zero-voltage condition.

[0171] In one implementation,

[0172] the control circuit 11 can determine whether the input voltage signal is less than or equal to a preset input voltage signal. For example, the preset input voltage signal can be 110V.

[0173] If so, the control circuit 11 can determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition. It should be noted that when the input voltage signal is less than or equal to the preset input voltage signal (such as 110V), the input voltage is much smaller than the output voltage, and the resonant current signal can completely drain the charge in the parasitic capacitance of the main switch tube, so that the main switch tube can be turned on under the zero-voltage condition without compensating the negative current signal.

[0174] If not, the control circuit 11 can determine whether the ratio of the input voltage signal to the output voltage signal is less than or equal to the preset ratio. If so, the control circuit 11 can determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition. If not, the control circuit 11 can determine that the bridgeless totem-pole PFC circuit meets the current compensation condition.

[0175] Advantageous Effects of This Embodiment: In this embodiment, the control circuit can determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation conditions based on circuit parameters. If the bridgeless totem-pole PFC circuit meets the negative current compensation conditions, the control circuit can determine the dead-band duration and negative current threshold by consulting a preset table. Based on the negative current threshold, the control circuit can control the freewheeling diode to be disconnected, so that the compensated negative current signal can drain the charge in the parasitic capacitance of the main switch within the dead-band duration. This allows the control circuit to turn on the main switch under zero voltage conditions when controlling the main switch based on the dead-band duration. If the bridgeless totem-pole PFC circuit does not meet the negative current compensation conditions, the control circuit can determine the negative current threshold to be zero. Based on this negative current threshold, the control circuit can control the freewheeling diode to be disconnected, so that the negative current signal can drain the charge in the parasitic capacitance of the main switch within the dead-band duration without compensating the negative current signal. This allows the control circuit to turn on the main switch under zero voltage conditions when controlling the main switch based on the dead-band duration. Through the above method, the actual negative current signal can be matched with the negative current signal requirement, thereby reducing the loss of the bridgeless totem pole PFC circuit.

[0176] Figure 6 A schematic diagram of a control circuit provided in an embodiment of the present application Figure 1 .

[0177] The bridgeless totem-pole PFC circuit 12 may include a current detection resistor R0 and an inductor L.

[0178] like Figure 6 As shown, the control circuit 11 may include a controller 111, a comparison circuit 112, and a differential amplifier circuit 113. It should be noted that the controller may be a digital signal processor (DSP). The controller may also be other types of controllers, which are not limited in the embodiments of the present application.

[0179] The first terminal 112 a of the comparison circuit 112 is connected to the first terminal 113 a of the differential amplifier circuit 113 .

[0180] The second terminal 112b of the comparison circuit 112 is connected to the current detection resistor R0 and the inductor L respectively ( Figure 6 not shown).

[0181] The third terminal 112 c of the comparison circuit 112 is connected to the first terminal 111 a of the controller 111 .

[0182] The second terminal 111b of the controller 111 is connected to the main switch tube ( Figure 6 (not shown). For example, Figure 6As shown, when the main switching transistor is Q3, the end of the controller 111 connected to Q3 is the second end 111b of the controller 111.

[0183] The third end 111c of the controller 111 is connected to the freewheeling diode. Exemplarily, as Figure 6 shown, when the freewheeling diode is Q4, the end of the controller 111 connected to Q4 is the third end 111c of the controller 111.

[0184] The fourth end 111d of the controller 111 is connected to the second end 113b of the differential amplifier circuit 113. The fifth end 111e of the controller 111 is connected to the third end 113c of the differential amplifier circuit 113.

[0185] In addition, it should be noted that, in one implementation, Figure 7 is a schematic structural diagram of a control circuit provided by an embodiment of the present application Figure 2 . As Figure 7 shown, the differential amplifier circuit 113 includes an operational amplifier 1131, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. Among them, the first end 1131a of the operational amplifier 1131 is respectively connected to the first end R1a of the first resistor R1 and the first end R2a of the second resistor R2. The second end 1131b of the operational amplifier 1131 is respectively connected to the first end R3a of the third resistor R3 and the first end R4a of the fourth resistor R4. The second end of the first resistor R1 (the second end of the first resistor R1 is the second end 113b of the differential amplifier circuit) is connected to the fourth end 111d of the controller 111, and the second end R2b of the second resistor R2 is connected to the third end 1131c of the operational amplifier 1131. The second end of the third resistor R3 (the second end of the third resistor R3 is the third end 113c of the differential amplifier circuit) is connected to the fifth end 111e of the controller 111, and the second end R4b of the fourth resistor R4 is connected to the ground. The third end of the operational amplifier 1131 (the third end of the operational amplifier 1131 is the first end 113a of the differential amplifier circuit 113) is connected to the first end 112a of the comparison circuit 112.

[0186] In one implementation, the fifth end 111e of the controller 111 can be a digital-to-analog conversion terminal.

[0187] In one implementation, Figure 8 is a schematic structural diagram of a control circuit provided by an embodiment of the present application Figure 3 , as Figure 8As shown, when the fifth terminal 111e of the controller 111 is not a digital-to-analog conversion terminal, the differential amplifier circuit 113 may further include a filter capacitor C2. Among them, the first terminal C2a of the filter capacitor C2 is connected to the first terminal R4a of the fourth resistor R4, and the second terminal C2b of the filter capacitor C2 is connected to the second terminal R4b of the fourth resistor R4.

[0188] Next, in conjunction with Figures 6 - 8 , the process in which the control circuit 11 can control the freewheeling diode to turn off according to the negative current threshold and control the main switch to turn on under the zero-voltage condition according to the dead time will be described.

[0189] The controller 111 can monitor circuit parameters. Among them, the circuit parameters include the delay duration, the input voltage signal, the output voltage signal, the inductance value of the inductor L, and the capacitance value of the parasitic capacitance; the delay duration includes the circuit delay duration and the delay duration corresponding to the freewheeling diode. In addition, it should be noted that based on the capacitance value of the parasitic capacitance of the main switch being the same as the capacitance value of the parasitic capacitance of the freewheeling diode, the capacitance value of the parasitic capacitance included in the circuit parameters is the same as the capacitance value of the parasitic capacitance of the main switch and is the same as the capacitance value of the parasitic capacitance of the freewheeling diode.

[0190] The controller 111 can query a preset table according to the circuit parameters to determine the dead time and the negative current threshold.

[0191] The controller 111 can perform conversion processing on the negative current threshold (digital signal) to obtain a first signal (analog signal).

[0192] The differential amplifier circuit 113 can obtain the first signal sent by the controller 111 through the second terminal 113b of the differential amplifier circuit 113 and the fourth terminal 111d of the controller 111.

[0193] The differential amplifier circuit 113 can obtain the reference signal sent by the controller 111 through the third terminal 113c of the differential amplifier circuit 113 and the fifth terminal 111e of the controller 111.

[0194] In one implementation, when the fifth terminal 111e of the controller 111 is a digital-to-analog conversion terminal, the reference signal can be an analog signal. For example, the analog signal can be 0.5_DAC (half of the full-scale output of the digital-to-analog conversion terminal).

[0195] In one implementation, when the fifth terminal 111e of the controller 111 is not a digital-to-analog conversion terminal, the reference signal can be a Pulse-Width Modulation (PWM) signal. Figure 9 A schematic diagram of a PWM signal provided by an embodiment of the present application is shown in Figure 9As shown, for example, the PWM signal can be a PWM signal with a 50% duty cycle. The differential amplifier circuit 113 may include a filter capacitor C2. The differential amplifier circuit 113 can filter the PWM signal through the filter capacitor C2 to obtain an analog signal. Additionally, in one implementation, the filter capacitor C2 can be a filter capacitor with a large capacitance value to improve the smoothness of the analog signal. It should be noted that through the above method, when the digital-to-analog conversion terminal of the controller 111 is insufficient, the differential amplifier circuit 113 can still obtain an analog signal.

[0196] The differential amplifier circuit 113 can perform differential amplification processing on the first signal and the reference signal (or the filtered reference signal) to obtain a differential amplified signal.

[0197] The comparison circuit 112 can obtain the differential amplified signal sent by the differential amplifier circuit 113 through the first terminal 112a of the comparison circuit 112 and the first terminal 113a of the differential amplifier circuit 113.

[0198] The comparison circuit 112 can obtain a negative current signal through the second terminal 112b of the comparison circuit 112. It should be noted that the negative current signal is obtained by the current detection resistor R0 detecting the negative current signal flowing through the inductor L.

[0199] The comparison circuit 112 can compare the differential amplified signal and the negative current signal and output a corresponding level signal according to the comparison result. In one implementation, the comparison circuit 112 can output a low level signal (such as VS-) when it determines that the negative current signal exceeds the differential amplified signal. The comparison circuit 112 can output a high level signal (such as VS+) when it determines that the negative current signal does not exceed the differential amplified signal.

[0200] In one implementation, the controller 111 obtains the level signal output by the comparison circuit 112 through the first terminal 111a of the controller 111 and the third terminal 112c of the comparison circuit 112. The controller 111 can control the freewheeling diode to turn off when it monitors that the level signal changes, that is, when the controller 111 monitors that the level signal output by the comparison circuit flips. The controller 111 can control the main switch tube to turn on under zero voltage conditions according to the dead time duration.

[0201] Advantages of this embodiment: In this embodiment, the bridgeless totem-pole PFC circuit may include a current detection resistor and an inductor. The control circuit includes a controller, a comparison circuit, and a differential amplification circuit. Among them, the first end of the comparison circuit is connected to the first end of the differential amplification circuit; the second end of the comparison circuit is respectively connected to the current detection resistor and the inductor; the third end of the comparison circuit is connected to the first end of the controller; the second end of the controller is connected to the main switch tube, the third end of the controller is connected to the freewheeling diode, the fourth end of the controller is connected to the second end of the differential amplification circuit, and the fifth end of the controller is connected to the third end of the differential amplification circuit. Based on this structure, the controller of the control circuit can control the freewheeling diode to turn off according to the queried negative current threshold, and control the main switch tube to turn on under zero voltage conditions according to the dead time, so that the compensated negative current signal can match the actual negative current signal demand. Therefore, while the compensated negative current signal extracts all the charges in the parasitic capacitance of the main switch tube within the dead time, it can avoid the problem that the compensated negative current signal is too large, resulting in excessive loss of the main switch tube and further excessive loss of the bridgeless totem-pole PFC circuit.

[0202] Figure 10 Schematic flow of a control method provided by an embodiment of the present application Figure 1 . This method is applied to the control circuit in any of the foregoing embodiments. Specifically, the computing device includes a power supply module, the power supply module includes a control circuit and a bridgeless totem-pole PFC circuit, the bridgeless totem-pole PFC circuit includes a main switch tube and a freewheeling diode, and the control circuit is connected to the freewheeling diode. Refer to Figure 10 . Specifically, this method includes the following steps:

[0203] S1001: Monitor the circuit parameters of the bridgeless totem-pole PFC circuit.

[0204] In this embodiment, the control circuit can monitor the circuit parameters of the bridgeless totem-pole PFC circuit.

[0205] Among them, the circuit parameters may include the delay duration, the input voltage signal, the output voltage signal, the inductance value of the inductor, and the capacitance value of the parasitic capacitance.

[0206] It should be noted that based on the fact that the capacitance value of the parasitic capacitance of the main switch tube is the same as the capacitance value of the parasitic capacitance of the freewheeling diode, the capacitance value of the parasitic capacitance included in this circuit parameter is the same as the capacitance value of the parasitic capacitance of the main switch tube and is also the same as the capacitance value of the parasitic capacitance of the freewheeling diode.

[0207] It should also be noted that the delay duration may include the circuit delay duration and the delay duration corresponding to the freewheeling diode.

[0208] In one implementation,

[0209] The bridgeless totem-pole PFC circuit may include a current sensing resistor and an inductor. The control circuit may include a controller, a comparison circuit, and a differential amplifier circuit. Among them, the first end of the comparison circuit is connected to the first end of the differential amplifier circuit; the second end of the comparison circuit is respectively connected to the current sensing resistor and the inductor; the third end of the comparison circuit is connected to the first end of the controller; the second end of the controller is connected to the main switch tube, the third end of the controller is connected to the freewheeling diode, the fourth end of the controller is connected to the second end of the differential amplifier circuit, and the fifth end of the controller is connected to the third end of the differential amplifier circuit.

[0210] The controller in the control circuit can monitor the circuit parameters of the bridgeless totem-pole PFC circuit.

[0211] S1002: Query a preset table according to the circuit parameters to determine the dead time and the negative current threshold.

[0212] In this embodiment, the control circuit can store the preset table. In one implementation, the controller in the control circuit can store the preset table. Among them, the preset table indicates the correspondence between the circuit parameters, the dead time, and the negative current threshold.

[0213] The control circuit can query the preset table according to the circuit parameters to determine the dead time and the negative current threshold.

[0214] S1003: Control the freewheeling diode to turn off according to the negative current threshold.

[0215] In this embodiment, the control circuit can control the freewheeling diode to turn off according to the negative current threshold.

[0216] S1004: Control the main switch tube to turn on under zero voltage conditions according to the dead time.

[0217] In this embodiment, the control circuit can control the main switch tube to turn on under zero voltage conditions according to the dead time.

[0218] Advantages of this embodiment: In this embodiment, the computing device may include a power supply module, and the power supply module may include a control circuit and a bridgeless totem-pole PFC circuit. The bridgeless totem-pole PFC circuit includes a main switch tube and a freewheeling diode, and the control circuit may be connected to the freewheeling diode. The control circuit may monitor the circuit parameters of the bridgeless totem-pole PFC circuit, and according to the circuit parameters, query a preset table to determine the dead time duration and the negative current threshold. Among them, the preset table indicates the corresponding relationship between the circuit parameters and the dead time duration and the negative current threshold. The control circuit may control the freewheeling diode to turn off according to the negative current threshold, and control the main switch tube to turn on under the zero-voltage condition according to the dead time duration. By the above method of determining the dead time duration and the negative current threshold based on the monitored circuit parameters, the compensated negative current signal can be matched with the actual negative current signal requirement, so that the compensated negative current signal can extract all the charges in the parasitic capacitance of the main switch tube within the dead time duration, while avoiding the problem that the compensated negative current signal is too large and causes excessive loss of the main switch tube. In addition, by pre-constructing a preset table indicating the corresponding relationship between the circuit parameters and the dead time duration and the negative current threshold, the control circuit can quickly determine the negative current threshold and the dead time duration corresponding to the circuit parameters by looking up the table, reducing the computing power requirement for the control circuit, and further reducing the cost of the control circuit. In addition, by dynamically determining the dead time duration and the negative current threshold based on the monitored circuit parameters, the peak current signal of the inductor is reduced, and further the saturation requirement for the inductor is reduced, thereby reducing the cost of the inductor.

[0219] Figure 11 Schematic flow of a control method provided by an embodiment of the present application Figure 2 . See Figure 11 , the method specifically includes the following steps:

[0220] S1101: Monitor the circuit parameters of the bridgeless totem-pole PFC circuit.

[0221] In this embodiment, the control circuit may monitor the circuit parameters of the bridgeless totem-pole PFC circuit.

[0222] Among them, the circuit parameters may include the delay duration, the input voltage signal, the output voltage signal, the inductance value of the inductor, and the capacitance value of the parasitic capacitance.

[0223] The delay duration may include the circuit delay duration and the delay duration corresponding to the freewheeling diode.

[0224] S1102: Determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition according to the circuit parameters.

[0225] In this embodiment, the control circuit may determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition according to the circuit parameters.

[0226] If so, execute S1103;

[0227] If not, execute S1104.

[0228] Next, the process by which the control circuit determines whether the bridgeless totem-pole PFC circuit satisfies the negative current compensation condition according to the circuit parameters will be described.

[0229] In one implementation,

[0230] The control circuit can determine whether the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio. It should be noted that the preset ratio can be 0.5.

[0231] If so, the control circuit can determine that the bridgeless totem-pole PFC circuit does not satisfy the negative current compensation condition.

[0232] If not, the control circuit can determine that the bridgeless totem-pole PFC circuit satisfies the negative current compensation condition.

[0233] In one implementation,

[0234] The control circuit can determine whether the input voltage signal is less than or equal to a preset input voltage signal. For example, the preset input voltage signal can be 11V0.

[0235] If so, the control circuit can determine that the bridgeless totem-pole PFC circuit does not satisfy the negative current compensation condition.

[0236] If not, the control circuit can determine whether the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio. If so, the control circuit can determine that the bridgeless totem-pole PFC circuit does not satisfy the negative current compensation condition. If not, the control circuit can determine that the bridgeless totem-pole PFC circuit satisfies the negative current compensation condition.

[0237] S1103: Query the preset table to determine the dead time and negative current threshold corresponding to the circuit parameters.

[0238] In this embodiment, the control circuit can query the preset table to determine the dead time and negative current threshold corresponding to the circuit parameters when it is determined that the bridgeless totem-pole PFC circuit satisfies the negative current compensation condition.

[0239] S1104: Determine that the negative current threshold is zero and query the preset table to determine the dead time corresponding to the circuit parameters.

[0240] In this embodiment, the control circuit can determine that the negative current threshold is zero when it is determined that the bridgeless totem-pole PFC circuit does not satisfy the negative current compensation condition.

[0241] The control circuit can determine the dead time corresponding to the circuit parameters by querying a preset table.

[0242] S1105: Control the freewheeling diode to turn off according to the negative current threshold.

[0243] In this embodiment, the control circuit can control the freewheeling diode to turn off according to the negative current threshold.

[0244] S1106: Control the main switch to turn on under zero voltage conditions according to the dead time.

[0245] In this embodiment, the control circuit can control the main switch to turn on under zero voltage conditions according to the dead time.

[0246] Advantages of this embodiment: In this embodiment, the control circuit can determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition based on the circuit parameters. When the bridgeless totem-pole PFC circuit meets the negative current compensation condition, the control circuit can determine the dead time and the negative current threshold by querying a preset table, and then control the freewheeling diode to turn off based on the dead time and the negative current threshold, so that the compensated negative current signal can evacuate the charge in the parasitic capacitance of the main switch within the dead time, thereby enabling the control circuit to control the main switch to turn on under zero voltage conditions when controlling the main switch based on the dead time. When the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition, the control circuit can determine that the negative current threshold is zero, query the preset table to determine the dead time, and then control the freewheeling diode to turn off based on the negative current threshold, so that the negative current can evacuate the charge in the parasitic capacitance of the main switch within the dead time without compensating the negative current, thereby enabling the control circuit to control the main switch to turn on under zero voltage conditions when controlling the main switch based on the dead time. Through the above method, the negative current signal can be matched with the actual negative current signal requirement, thereby reducing the loss of the bridgeless totem-pole PFC circuit.

[0247] The embodiment of the present application provides a computer-readable storage medium, on which computer-executable instructions are stored; when the computer-executable instructions are executed by a processor, they are used to implement the control method as described in the above embodiment.

[0248] The embodiment of the present application provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the computer is enabled to execute the control method as described in the above embodiment.

[0249] Embodiments of the present application are described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processing unit of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable devices to generate a machine, so that the instructions executed by the processing unit of the computer or other programmable devices generate a means for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 or a means for implementing the functions specified in multiple blocks.

[0250] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction means, and the instruction means implements the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 or a means for implementing the functions specified in multiple blocks.

[0251] These computer program instructions can also be loaded onto a computer or other programmable device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 or a means for implementing the functions specified in multiple blocks.

[0252] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, and are not intended to limit them; although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A computing device, characterized in that, The computing device includes a power supply module, the power supply module includes a control circuit and a bridgeless totem-pole power factor correction (PFC) circuit, the bridgeless totem-pole PFC circuit includes a main switch transistor and a freewheeling diode, and the control circuit is connected to the freewheeling diode and the main switch transistor; the control circuit is configured to: Monitor the circuit parameters of the bridgeless totem-pole PFC circuit; the bridgeless totem-pole PFC circuit includes an inductor and a parasitic capacitor; the circuit parameters include a delay duration, an input voltage signal, an output voltage signal, the inductance value of the inductor, and the capacitance value of the parasitic capacitor; the delay duration includes a circuit delay duration and a delay duration corresponding to the freewheeling diode; Query a preset table according to the circuit parameters to determine a dead time duration and a negative current threshold; The preset table indicates the corresponding relationship between the circuit parameters, the dead time duration, and the negative current threshold; Control the freewheeling diode to turn off according to the negative current threshold; Control the main switch transistor to turn on under zero voltage conditions according to the dead time duration.

2. The computing device according to claim 1, wherein The bridgeless totem-pole PFC circuit includes a current sensing resistor and an inductor; the control circuit includes a controller, a comparator circuit, and a differential amplifier circuit; The first terminal of the comparator circuit is connected to the first terminal of the differential amplifier circuit; The second terminal of the comparator is respectively connected to the current sensing resistor and the inductor; The third terminal of the comparator is connected to the first terminal of the controller; The second terminal of the controller is connected to the main switch transistor, the third terminal of the controller is connected to the freewheeling diode, the fourth terminal of the controller is connected to the second terminal of the differential amplifier circuit, and the fifth terminal of the controller is connected to the third terminal of the differential amplifier circuit.

3. The computing device according to claim 2, wherein The differential amplifier circuit includes an operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor; The first terminal of the operational amplifier is respectively connected to the first terminal of the first resistor and the first terminal of the second resistor; The second terminal of the operational amplifier is respectively connected to the first terminal of the third resistor and the first terminal of the fourth resistor; The second terminal of the first resistor is connected to the fourth terminal of the controller, and the second terminal of the second resistor is connected to the third terminal of the operational amplifier; The second terminal of the third resistor is connected to the fifth terminal of the controller, and the second terminal of the fourth resistor is connected to ground; The third terminal of the operational amplifier is connected to the first terminal of the comparator circuit.

4. The computing device according to claim 3, wherein The fifth terminal of the controller is a digital-to-analog conversion terminal.

5. The computing device according to claim 3, wherein When the fifth terminal of the controller is not a digital-to-analog conversion terminal, the differential amplifier circuit further includes a filter capacitor, the first terminal of the filter capacitor is connected to the first terminal of the fourth resistor, and the second terminal of the filter capacitor is connected to the second terminal of the fourth resistor.

6. The computing device according to any one of claims 1-5, characterized in that, The control circuit is specifically configured to: Determine whether the bridgeless totem-pole PFC circuit meets the negative current compensation condition according to the circuit parameters; If so, query the preset table to determine the dead time duration and the negative current threshold corresponding to the circuit parameters; If not, determine that the negative current threshold is zero, and query the preset table to determine the dead time duration corresponding to the circuit parameters.

7. The computing device according to claim 6, wherein The parasitic capacitance is the parasitic capacitance of the main switching transistor.

8. The computing device according to claim 7, wherein The control circuit is specifically configured to: Determine whether the ratio of the input voltage signal to the output voltage signal is less than or equal to a preset ratio; If so, determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition; If not, determine that the bridgeless totem-pole PFC circuit meets the negative current compensation condition.

9. The computing device according to claim 8, wherein The control circuit is further configured to: Determine whether the input voltage signal is less than or equal to a preset input voltage signal; If so, determine that the bridgeless totem-pole PFC circuit does not meet the negative current compensation condition.

10. The computing device according to any one of claims 1-9, characterized in that, The control circuit is specifically configured to: Based on a preset look-up table frequency, query the preset table according to the circuit parameters to determine the dead time duration and the negative current threshold.

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