Totem pole power factor correction circuit and power supply equipment

Abstract

The embodiment of the invention discloses a totem pole power factor correction circuit and power supply equipment. The circuit comprises a sampling unit and a detection control unit, the sampling unit comprises a first sampling resistor and a second sampling resistor, the first sampling resistor is electrically connected between a second connection point and an anode of a first diode, and the second sampling resistor is electrically connected between the second connection point and a cathode of a second diode; the detection control unit can output a control signal through the voltage at the two ends of the first sampling resistor or the second sampling resistor or the voltage at the two ends of the series connection of the first sampling resistor and the second sampling resistor so as to carry out driving blocking on the third switch or the fourth switch. Therefore, the damage to components caused by the fact that the third switch or the fourth switch is not turned off in time can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the technical field of power factor correction, and in particular to a totem pole power factor correction circuit and a power supply device. Background Art

[0002] In server power supplies, totem pole PFC (Power Factor Correction) circuits are increasingly used due to their high efficiency. Figure 1 As shown, the switch tube D1 and the switch tube D2 are both polarity tubes, that is, when the polarity of the input current is reversed, the conduction of the switch tube D1 and the switch tube D2 will also be reversed; the switch tube S1 and the switch tube S2 are both fast tubes, which can realize energy control in the circuit. Figure 1 On the basis of, the switch tube D1 and the switch tube D2 can also be replaced by MOS tube S3 and MOS tube S4, such as Figure 2 As shown, the MOS tube S3 and the MOS tube S4 work as synchronous rectifier tubes, and are turned on when their respective body diodes are turned on, thereby reducing the conduction voltage drop of the switch tube.

[0003] In the prior art, in order to perform surge protection on the switch tube in the totem pole PFC circuit, the totem pole PFC circuit is usually provided with the following Figure 3 The bypass circuit shown in FIG. 1 adds diodes Db1 and Db2 before inductor L1, so that when a surge occurs in the totem pole PFC circuit, the surge energy can be bypassed to bus capacitor C1 through diodes Db1, Db2 and each switch tube. However, when the totem pole PFC circuit is in an abnormal state, the voltage of the input power supply suddenly reverses, such as Figure 4 As shown, the input power suddenly reverses in the positive half cycle, and the switch tube S4 cannot be turned off in time, and the switch tube S4 and the diode Db2 will be directly short-circuited. At this time, within a few hundred nanoseconds, a large impact current will inevitably be generated in the circuit, which will cause damage to the components in the circuit.

[0004] Therefore, how to reliably detect the abnormal state of the totem pole PFC circuit and promptly avoid damage to components in the circuit is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present application provides a totem pole power factor correction circuit and power supply device, which aims to solve the technical problem in the prior art that components in the circuit are damaged when the voltage of the input power supply suddenly reverses.

[0006] To solve the above technical problems, in a first aspect, an embodiment of the present application provides a totem pole power factor correction circuit, which includes:

[0007] A first bridge arm, comprising a first switch and a second switch connected in series, wherein a connection point between the first switch and the second switch forms a first connection point;

[0008] a bypass unit connected in parallel with the first bridge arm and comprising a first diode and a second diode connected in series, wherein a connection point between the first diode and the second diode forms a second connection point, and the second connection point is electrically connected to a first end of an AC power source;

[0009] a first inductor, electrically connected between the first connection point and the second connection point;

[0010] a second bridge arm connected in parallel with the first bridge arm and comprising a third switch and a fourth switch connected in series, wherein a connection point between the third switch and the fourth switch forms a third connection point, and the third connection point is electrically connected to a second end of the AC power supply;

[0011] A sampling unit, comprising a first sampling resistor and a second sampling resistor, wherein the first sampling resistor is electrically connected between the second connection point and the anode of the first diode, and the second sampling resistor is electrically connected between the second connection point and the cathode of the second diode;

[0012] a detection control unit, electrically connected to both ends of the first sampling resistor and both ends of the second sampling resistor, respectively; when the voltage across the first sampling resistor is greater than a preset first voltage, or less than the first voltage, the detection control unit outputs a control signal to drive and block the third switch or the fourth switch; when the voltage across the second sampling resistor is greater than a preset second voltage, or less than the second voltage, the detection control unit outputs the control signal to drive and block the third switch or the fourth switch; or

[0013] The detection control unit is electrically connected between the anode of the first diode and the first sampling resistor, and between the cathode of the second diode and the second sampling resistor. When the voltage across the first sampling resistor and the second sampling resistor in series is greater than or less than a preset third voltage, the detection control unit outputs the control signal to drive and block the third switch and the fourth switch.

[0014] Further, in the totem pole power factor correction circuit, the detection control unit includes a first comparator and a second comparator, and the control signal includes a first control signal and a second control signal;

[0015] The first comparator includes a first input terminal, a second input terminal and a first output terminal, the first input terminal receives the voltage across the first sampling resistor, the second input terminal receives the first voltage, and the first output terminal is used to output the first control signal to drive and block the third switch or the fourth switch;

[0016] The second comparator includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal receives the voltage across the second sampling resistor, the fourth input terminal receives the second voltage, and the second output terminal is used to output the second control signal to drive and block the third switch or the fourth switch.

[0017] Furthermore, in the totem pole power factor correction circuit, the first comparator also includes a first ground terminal, and the second comparator also includes a second ground terminal; the first ground terminal and the second ground terminal are respectively grounded to the first terminal of the AC power supply.

[0018] Furthermore, in the totem pole power factor correction circuit, the first output end is used to output the first control signal to drive and block the third switch; the second output end is used to output the second control signal to drive and block the fourth switch.

[0019] Furthermore, in the totem pole power factor correction circuit, the control signal also includes a third control signal, and the third control signal is generated after a logic operation of the first control signal and the second control signal.

[0020] Further, in the totem pole power factor correction circuit, the detection control unit includes a third comparator;

[0021] The third comparator includes a fifth input terminal, a sixth input terminal and a third output terminal, the fifth input terminal receives the voltage across the first sampling resistor and the second sampling resistor in series, the sixth input terminal receives the third voltage, and the third output terminal is used to output a control signal to drive and block the third switch and the fourth switch.

[0022] Furthermore, in the totem pole power factor correction circuit, the third comparator also includes a third ground terminal, and the third ground terminal is grounded to the first terminal of the AC power supply.

[0023] Furthermore, in the totem pole power factor correction circuit, the detection control unit further includes a drive circuit;

[0024] Wherein, the driving circuit receives an output control signal to drive and block the third switch and / or the fourth switch;

[0025] The driving circuit is electrically connected to the first output terminal of the first comparator and the second output terminal of the second comparator respectively; or the driving circuit is electrically connected to the third output terminal of the third comparator.

[0026] Furthermore, in the totem pole power factor correction circuit, the detection control unit further includes an isolation circuit;

[0027] Among them, the isolation circuit is arranged between the driving circuit and the first comparator, and the driving circuit and the first comparator do not share a common ground; or / and the isolation circuit is arranged between the driving circuit and the second comparator, and the driving circuit and the second comparator do not share a common ground; or the isolation circuit is arranged between the driving circuit and the third comparator, and the driving circuit and the third comparator do not share a common ground.

[0028] Furthermore, in the totem pole power factor correction circuit, the control signal is a high level signal or a low level signal.

[0029] Furthermore, in the totem pole power factor correction circuit, the first switch, the second switch, the third switch and the fourth switch are any one of a MOSFET switch tube, an IGBT switch tube, a GaN switch tube or a SiC switch tube.

[0030] Furthermore, in the totem pole power factor correction circuit, the totem pole power factor correction circuit is a multi-phase interleaved parallel circuit.

[0031] Furthermore, in the totem pole power factor correction circuit, the totem pole power factor correction circuit further includes a third bridge arm and a second inductor;

[0032] Among them, the third bridge arm is connected in parallel with the first bridge arm, and the third bridge arm includes a fifth switch and a sixth switch connected in series, a fifth connection point is formed between the fifth switch and the sixth switch, the fifth connection point is electrically connected to the second connection point, and the second inductor is electrically connected between the second connection point and the fifth connection point.

[0033] Furthermore, in the totem pole power factor correction circuit, the first bridge arm and the third bridge arm work alternately.

[0034] In a second aspect, an embodiment of the present application further provides a power supply device, which includes the totem pole power factor correction circuit described in the first aspect.

[0035] In the totem pole power factor correction circuit provided in the present application, a sampling unit and a detection control unit are additionally added in the circuit, the sampling unit is composed of a first sampling resistor and a second sampling resistor, the first sampling resistor is arranged between the first diode in the bypass unit and the first end of the AC power supply, and the second sampling resistor is arranged between the second diode in the bypass unit and the first end of the AC power supply. The detection control unit can accurately detect the voltage across the first sampling resistor and the second sampling resistor, or the voltage across the first sampling resistor and the second sampling resistor in series, so as to determine whether the voltage of the input power supply in the circuit is abnormal, and timely output a control signal to drive and block the third switch and / or the fourth switch, thereby avoiding damage to components caused by the third switch and the fourth switch not being turned off in time, thereby improving the service life of the components in the circuit and reducing the use cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 The topology diagram of the existing totem pole power factor correction circuit is shown;

[0038] Figure 2 It is another topology diagram of the existing totem pole power factor correction circuit;

[0039] Figure 3 It is another topology diagram of the existing totem pole power factor correction circuit;

[0040] Figure 4 The voltage waveform diagram of the AC power supply VAC provided for this application;

[0041] Figure 5 The AC power supply VAC provided for this application is at t 1 ~t 2 The current flow topology diagram during the phase;

[0042] Figure 6 A topological diagram of a totem pole power factor correction circuit provided for this application;

[0043] Figure 7 Another topological diagram of the totem pole power factor correction circuit provided by the present application;

[0044] Figure 8 A current flow topology diagram of the totem pole power factor correction circuit provided by the present application when the AC power supply VAC is in the positive half cycle;

[0045] Fig. 9 Another topological diagram of the current flow of the totem pole power factor correction circuit provided by the present application when the AC power supply VAC is in the positive half cycle;

[0046] Fig.10 Another topological diagram of the current flow of the totem pole power factor correction circuit provided by the present application when the AC power supply VAC is in the positive half cycle;

[0047] Fig.11 Another topological diagram of the current flow of the totem pole power factor correction circuit provided by the present application when the AC power supply VAC is in the negative half cycle;

[0048] Fig.12 A topological diagram of a comparator in a totem pole power factor correction circuit provided in the present application;

[0049] Fig.13 A topological diagram of a detection control unit in a totem pole power factor correction circuit provided in the present application;

[0050] Fig.14 Another topological diagram of the totem pole power factor correction circuit provided by the present application;

[0051] Fig.15 Another topological diagram of the totem pole power factor correction circuit provided in this application. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0054] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0055] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0056] In the prior art, such as Figure 4 As shown in FIG. 1 , when the AC power supply VAC is in the positive half cycle, the fourth switch tube S4 is in the on state, and the input AC power supply VAC suddenly reverses its polarity, that is, the positive voltage changes to the negative voltage. If the fourth switch tube S4 is not turned off in time, the current in the totem pole power factor correction circuit flows as shown in FIG. Figure 5 As shown, the current provided by the AC power supply VAC changes to flow out from the second end b, and flows to the fourth switch S4, the second diode Db2 and then to the first end a of the AC power supply VAC. At this time, the AC power supply VAC is short-circuited through the fourth switch tube S4 and the second diode Db2, and a large impact current will inevitably be generated in the circuit, which is very likely to cause damage to the components in the circuit.

[0057] To solve the above problems, Figure 6 As shown, the embodiment of the present application provides a totem pole power factor correction circuit, which includes: a first bridge arm 10, a second bridge arm 20, a bypass unit 30, a first inductor L1, a sampling unit 40 and a detection control unit 50;

[0058] The first bridge arm 10 includes a first switch S1 and a second switch S2 connected in series, and a connection point between the first switch S1 and the second switch S2 forms a first connection point A;

[0059] The bypass unit 30 is connected in parallel with the first bridge arm 10, and includes a first diode Db1 and a second diode Db2 connected in series, wherein a connection point between the first diode Db1 and the second diode Db2 forms a second connection point B, and the second connection point B is electrically connected to a first terminal a of an AC power source VAC;

[0060] The first inductor L1 is electrically connected between the first connection point A and the second connection point B;

[0061] The second bridge arm 20 is connected in parallel with the first bridge arm 10, and includes a third switch S3 and a fourth switch S4 connected in series, wherein a connection point between the third switch S3 and the fourth switch S4 forms a third connection point C, and the third connection point C is electrically connected to a second end b of the AC power source VAC;

[0062] The sampling unit 40 includes a first sampling resistor Rs1 and a second sampling resistor Rs2, wherein the first sampling resistor Rs1 is electrically connected between the second connection point B and the anode of the first diode Db1, and the second sampling resistor Rs2 is electrically connected between the second connection point B and the cathode of the second diode Db2;

[0063] The detection control unit 50 is electrically connected to both ends of the first sampling resistor Rs1 and both ends of the second sampling resistor Rs2 respectively; when the voltage across the first sampling resistor Rs1 is greater than a preset first voltage, or less than the first voltage, the detection control unit 50 outputs a control signal to drive and block the third switch S3 or the fourth switch S4; when the voltage across the second sampling resistor Rs2 is greater than a preset second voltage, or less than the second voltage, the detection control unit 50 outputs the control signal to drive and block the third switch S3 or the fourth switch S4.

[0064] After receiving the AC input power provided by the AC power supply VAC, the totem pole power factor correction circuit converts the AC input power into output power to the load. The AC power supply VAC has a first terminal a and a second terminal b. When the AC power supply VAC is in a positive half cycle, the voltage of the first terminal a of the AC power supply VAC is higher than the voltage of the second terminal b, and the current of the AC power supply VAC flows out from the first terminal a, so that the first terminal a constitutes the positive input terminal of the totem pole power factor correction circuit, and the current of the totem pole power factor correction circuit flows into the AC power supply VAC through the second terminal b, so that the second terminal b constitutes the negative input terminal of the totem pole power factor correction circuit; when the AC power supply VAC is in a negative half cycle, the voltage of the first terminal a of the AC power supply VAC is lower than the voltage of the second terminal b, and the current of the AC power supply VAC flows out from the second terminal b, so that the second terminal b constitutes the positive input terminal of the totem pole power factor correction circuit, and the current of the totem pole power factor correction circuit flows into the AC power supply VAC through the first terminal a, so that the first terminal a constitutes the negative input terminal of the totem pole power factor correction circuit. The totem pole power factor correction circuit is electrically coupled to the load, that is, the load can be directly connected to the totem pole power factor correction circuit or indirectly connected to the totem pole power factor correction circuit.

[0065] To illustrate the current flow of the totem pole power factor correction circuit provided by this application, please refer to Figure 8 , Fig. 9 , Fig.10 as well as Fig.11 , Figure 8 A current flow topology diagram of the totem pole power factor correction circuit provided in an embodiment of the present application when the AC power supply VAC is in the positive half cycle; Fig. 9Another topological diagram of the current flow of the totem pole power factor correction circuit provided in the embodiment of the present application when the AC power supply VAC is in the positive half cycle;

[0066] Fig.10 A current flow topology diagram of the totem pole power factor correction circuit provided in an embodiment of the present application when the AC power supply VAC is in the negative half cycle; Fig.11 This is another topological diagram of the current flow of the totem pole power factor correction circuit provided in the embodiment of the present application when the AC power supply VAC is in the negative half cycle. At the same time, in order to facilitate the description of the current flow of the totem pole power factor correction circuit provided in the present application, Figure 8 , Fig. 9 , Fig.10 as well as Fig.11 The detection control unit 50 is not shown.

[0067] When the totem pole power factor correction circuit is in normal working state, the AC power source VAC is in the positive half cycle, and the first inductor L1 is in the energy storage stage, such as Figure 7 As shown, the first switch S1 and the third switch S3 are in the off state, the second switch S2 and the fourth switch S4 are in the on state, and the current provided by the AC power supply VAC flows out from the first end a and flows to the first inductor L1, the second switch S2, the fourth switch S4 and the second end b of the AC power supply VAC in sequence to charge the first inductor L1.

[0068] When the totem pole power factor correction circuit is in normal working state, the AC power source VAC is in the positive half cycle, and the first inductor L1 has completed charging and is in the discharge stage, such as Figure 8 As shown, the second switch S2 and the third switch S3 are in the off state, the first switch S1 and the fourth switch S4 are in the on state, and the current provided by the AC power supply VAC flows out from the first end a and flows to the first inductor L1, the first switch S1, the bus capacitor C1, the fourth switch S4 and the second end b of the AC power supply VAC in sequence to charge the bus capacitor C1.

[0069] When the totem pole power factor correction circuit is in normal working state, the AC power supply VAC is in the negative half cycle, and the first inductor L1 is in the energy storage stage, such as Fig. 9 As shown, the first switch S1 and the third switch S3 are in the on state, the second switch S2 and the fourth switch S4 are in the off state, and the current provided by the AC power supply VAC flows out from the second end b and flows to the third switch S3, the first switch S1, the first inductor L1 and the first end a of the AC power supply VAC in sequence to charge the first inductor L1.

[0070] When the totem pole power factor correction circuit is in normal working state, the AC power source VAC is in the negative half cycle, and the first inductor L1 has completed charging and is in the discharge stage, such as Fig.10 As shown, the second switch S2 and the third switch S3 are in the on state, the first switch S1 and the fourth switch S4 are in the off state, and the current provided by the AC power supply VAC flows out from the second end b and flows to the third switch S3, the bus capacitor C1, the second switch S2, the first inductor L1 and the first end a of the AC power supply VAC in sequence to charge the bus capacitor C1.

[0071] Please continue reading Figure 6 When the voltage of the input power supply in the circuit is abnormal, the voltage across at least one of the first sampling resistor Rs1 and the second sampling resistor Rs2 in the sampling unit 40 will change. That is to say, when the voltage across the first sampling resistor Rs1 is greater than the preset first voltage, or less than the first voltage, the detection control unit 50 outputs a control signal to drive and block the third switch S3 or the fourth switch S4; when the voltage across the second sampling resistor Rs2 is greater than the preset second voltage, or less than the second voltage, the detection control unit 50 outputs a control signal to drive and block the third switch S3 or the fourth switch S4, thereby avoiding the third switch S3 and the fourth switch S4 from being damaged due to failure to turn off in time, thereby increasing the service life of the components in the circuit and reducing the use cost.

[0072] It should be noted that, in the present application, while turning off the third switch S3 and the fourth switch S4, the first switch S1 and the second switch S2 may also be turned off, thereby further protecting the components in the totem pole power factor correction circuit.

[0073] For example, the AC power supply VAC is in the positive half cycle. Figure 4 Medium 1 ~t 2 stage, from Figure 4 It can be seen that in this stage, the voltage input to the totem pole power factor correction circuit is directly reversed from the positive half-cycle polarity to the negative half-cycle, and the fourth switch S4 is still in the on state. At this time, the input voltage VAC passes through the fourth switch S4 and the second diode Db2 and the second sampling resistor Rs2, and the current increases rapidly. A voltage is generated across the second sampling resistor Rs2. The detection control unit 50 detects that the voltage across the second sampling resistor Rs2 increases and is higher than the preset second voltage. At this time, the detection control unit 50 can output a control signal to drive and block the fourth switch S4, and then turn off the fourth switch S4 in time, thereby avoiding excessive current between the fourth switch S4 and the second diode Db2, and reducing damage to components in the circuit.

[0074] Similarly, when the AC power supply VAC is in the negative half cycle, when the first inductor L1 is charged to the discharge stage, if the voltage input to the totem pole power factor correction circuit directly flips from the negative half cycle polarity to the positive half cycle, the third switch S3 is still in the on state. At this time, the input voltage VAC passes through the third switch S3, the first diode Db1, and the first sampling resistor Rs1, and the current increases rapidly. A voltage is generated across the first sampling resistor Rs1. The detection control unit 50 detects that the voltage across the first sampling resistor Rs1 rises and is higher than the preset first voltage. At this time, the detection control unit 50 can output a control signal to drive and block the third switch S3, and then turn off the third switch S3 in time, thereby avoiding excessive current between the third switch S3 and the first diode Db1, and reducing damage to components in the circuit.

[0075] It should be noted that the preset first voltage and the preset second voltage can be set according to the sampling resistors Rs1 and Rs2 and the protection current. When the voltage input to the totem pole power factor correction circuit suddenly reverses, the third switch S3 or the fourth switch S4 of the polarity tube is not turned off in time, the first sampling resistor Rs1 or the second sampling resistor Rs2 will generate a voltage due to the flow of current. When the voltage is greater than or less than the preset voltage, the detection control unit 50 will output a control signal to drive and block the third switch S3 or the fourth switch S4, thereby avoiding the formation of excessive current between the third switch S3 or the fourth switch S4 and the corresponding diode in the bypass unit 30.

[0076] It should also be noted that the detection control unit 50 can detect the change in the voltage across the first sampling resistor Rs1 to output a control signal, and then drive and block the third switch S3 or the fourth switch S4; it can also detect the change in the voltage across the second sampling resistor Rs2 to output a control signal, and then drive and block the third switch S3 or the fourth switch S4. It can also simultaneously detect the change in the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 to output a control signal, and then drive and block the third switch S3 or the fourth switch S4. The way in which the detection control unit 50 outputs the control signal can be selected according to the actual application, and this application does not make any specific limitation.

[0077] In some embodiments, Figure 6As shown, the detection control unit 50 includes a first comparator U1 and a second comparator U2, and the control signal includes a first control signal Signal1 and a second control signal Signal2; wherein the first comparator U1 includes a first input terminal, a second input terminal and a first output terminal, the first input terminal receives the voltage across the first sampling resistor Rs1, the second input terminal receives the first voltage, and the first output terminal is used to output the first control signal Signal1 to drive and block the third switch S3 or the fourth switch S4; the second comparator U2 includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal receives the voltage across the second sampling resistor Rs2, the fourth input terminal receives the second voltage, and the second output terminal is used to output the second control signal Signal2 to drive and block the third switch S3 or the fourth switch S4.

[0078] In this embodiment, the first input terminal and the second input terminal are one of the non-inverting input terminal and the inverting input terminal of the first comparator U1. That is to say, the voltage across the first sampling resistor Rs1 can be input into the non-inverting input terminal of the first comparator U1 or into the inverting input terminal of the first comparator U1. The first voltage is preset as the reference voltage.

[0079] Similarly, the third input terminal and the fourth input terminal are one of the non-inverting input terminal and the inverting input terminal of the second comparator U2, that is, the voltage across the second sampling resistor Rs2 can be input into the non-inverting input terminal of the second comparator U2, and can also be input into the inverting input terminal of the second comparator U2. The preset second voltage is also the reference voltage.

[0080] When the voltage input to the totem pole power factor correction circuit suddenly reverses, the voltage across the first sampling resistor Rs1 will be lower than or higher than the preset first voltage, or the voltage across the second sampling resistor Rs2 will be lower than or higher than the preset second voltage. At this time, the first comparator U1 or the second comparator U2 will output an opposite level signal, that is, the first control signal Signal1 or the second control signal Signal2, so that the third switch S3 or the fourth switch S4 can be driven and blocked to avoid a short circuit in the circuit.

[0081] In some embodiments, the control signal output by the detection control unit 50 can be a low-level signal or a high-level signal. It can be directly the first control signal Signal1 or the second control signal Signal2, or it can be obtained by logical operation of the first control signal Signal1 and the second control signal Signal2.

[0082] That is to say, the first control signal Signal1 output by the first comparator U1 and the second control signal Signal2 output by the second comparator U2 can be directly used to drive and block the third switch S3 or the fourth switch S4; the first control signal Signal1 output by the first comparator U1 can also be used alone to drive and block the third switch S3, and the second control signal Signal2 output by the second comparator U2 can also be used alone to drive and block the fourth switch S4; the first control signal Signal1 output by the first comparator U1 and the second control signal Signal2 output by the second comparator U2 can also generate a new control signal, such as the third control signal, after logical operation, to drive and block the third switch S3 or the fourth switch S4. The control signal for driving and blocking the third switch S3 or the fourth switch S4 can be selected according to the actual application, and the specific selection can be based on the actual application, and this application does not make specific limitations.

[0083] In some embodiments, the first comparator U1 further includes a first ground terminal, and the second comparator U2 further includes a second ground terminal; the first ground terminal and the second ground terminal are respectively grounded to the first terminal a of the AC power supply VAC.

[0084] In this embodiment, the first ground terminal in the first comparator U1 and the second ground terminal in the second comparator U2 are as follows: Fig.12 After the power supply terminal 5 of the comparator is electrically connected to the first terminal a of the AC power supply VAC to share the ground, the input terminal 1 of the comparator, that is, one of the input terminals of the first comparator U1 and the second comparator U2, Fig.12 The power supply terminal 4 of the comparator is connected to the power supply VCC, and the output terminal 3 outputs a level signal Signal.

[0085] In the present application, by electrically connecting the first ground terminal and the second ground terminal to the first terminal a of the AC power supply VAC to a common ground, the two ends of the first sampling resistor Rs1 can be directly electrically connected to an input end of the first comparator U1, and the input end can directly detect the voltage across the first sampling resistor Rs1; at the same time, the two ends of the second sampling resistor Rs2 can also be directly electrically connected to an input end of the second comparator U2, and similarly, the input end can also directly detect the voltage across the second sampling resistor Rs2.

[0086] In some embodiments, the control signal also includes a third control signal, which is generated by logic operation of the first control signal Signal1 and the second control signal Signal2. That is to say, the third control signal can trigger the generation of the third control signal after the level signal output by at least one of the first comparator U1 and the second comparator U2 changes, thereby achieving drive blocking of the third switch S3 or the fourth switch S4.

[0087] In addition, since the comparator usually has an open-drain output, the drive circuit can be directly connected to an Fig.13 The pull-up resistor R1 shown, the inverting input terminal and the non-inverting input terminal of the first comparator U1 can respectively receive the voltage Vs1 across the first sampling resistor Rs1 and the first voltage Vset1, and output the first control signal Signal1. At this time, the inverting input terminal and the non-inverting input terminal of the second comparator U2 need to respectively receive the voltage Vs2 across the second sampling resistor Rs2 and the second voltage Vset2, and output the second control signal Signal2. The first control signal Signal1 and the second control signal Signal2 can generate a level signal Signal through logical operation, that is, the third control signal, which can directly drive and block the third switch S3 or the fourth switch S4.

[0088] Alternatively, the non-inverting input terminal and the inverting input terminal of the first comparator U1 can respectively receive the voltage Vs1 across the first sampling resistor Rs1 and the first voltage Vset1, and output the first control signal Signal1. At this time, the non-inverting input terminal and the inverting input terminal of the second comparator U2 need to respectively receive the voltage Vs2 across the second sampling resistor Rs2 and the second voltage Vset2, and output the second control signal Signal2. The first control signal Signal1 and the second control signal Signal2 can generate a level signal Signal through logical operation, that is, the third control signal, which can directly drive and block the third switch S3 or the fourth switch S4.

[0089] That is to say, the input terminals of the first comparator U1 and the second comparator U2 that receive the reference voltage must be of the same type, such as the same-phase input terminal or the same-phase input terminal.

[0090] In another embodiment, Figure 7 As shown, the detection control unit 50 can also be electrically connected between the anode of the first diode Db1 and the first sampling resistor Rs1, and between the cathode of the second diode Db2 and the second sampling resistor Rs2; when the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 in series is greater than or less than a preset third voltage, the detection control unit 50 can output a control signal to drive and block the third switch S3 and the fourth switch S4.

[0091] In this embodiment, the current flow direction of the totem pole power factor correction circuit can refer to Figure 8 , Fig. 9 , Fig.10 as well as Fig.11 , I will not elaborate on this here.

[0092] Specifically, when the voltage of the input power supply in the circuit is abnormal, and the third switch S3 or the fourth switch S4 of the polarity tube is not closed in time, a current will be generated through the first diode Db1 or the second diode Db2 of the bypass bridge arm. At this time, no matter which diode is turned on, a voltage is generated across the first sampling resistor Rs1 and the second sampling resistor Rs2 in the sampling unit 40. When the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 in series is greater than or less than the preset third voltage, the detection control unit 50 can output a control signal to drive and block the third switch S3 and the fourth switch S4, thereby avoiding damage to components caused by the third switch S3 or the fourth switch S4 not being turned off in time, thereby increasing the service life of components in the circuit and reducing the use cost.

[0093] In some embodiments, Figure 7 As shown, the detection control unit includes a third comparator U3; wherein the third comparator U3 includes a fifth input terminal, a sixth input terminal, a third output terminal and a third ground terminal, the third ground terminal is shared with the first terminal of the AC power supply, the fifth input terminal receives the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 connected in series, the sixth input terminal receives the third voltage, and the third output terminal is used to output a control signal to drive and block the third switch S3 and the fourth switch S4.

[0094] In the present embodiment, the fifth input terminal and the sixth input terminal are one of the non-inverting input terminal and the inverting input terminal of the third comparator U3, that is, the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 connected in series can be input into the non-inverting input terminal of the third comparator U3 or the inverting input terminal of the third comparator U3. The preset third voltage is the reference voltage. When the voltage input into the totem pole power factor correction circuit is suddenly reversed, the third switch S3 or the fourth switch S4 of the polarity tube is not closed in time, and a current is generated through the first diode Db1 or the second diode Db2 of the bypass bridge arm. At this time, no matter which diode is turned on, a voltage is generated across the first sampling resistor Rs1 and the second sampling resistor Rs2 connected in series. When the voltage is lower than or higher than the preset third voltage, the third comparator U3 will definitely output an opposite level signal, that is, the control signal Signal, so that the third switch S3 and the fourth switch S4 can be driven and blocked to avoid a short circuit in the circuit.

[0095] At the same time, the third grounding terminal shares a common ground with the first terminal of the AC power supply, so that after the anode of the first diode Db1 and the first sampling resistor Rs1 and the cathode of the second diode Db2 and the second sampling resistor Rs2 are directly electrically connected, they can be directly electrically connected to an input terminal of the third comparator U3. The input terminal can directly detect the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 in series, thereby detecting abnormal driving of the third switch S3 or the fourth switch S4 of the polarity tube and outputting a control signal to achieve drive blocking of the third switch S3 and the fourth switch S4.

[0096] In some embodiments, the detection control unit 50 also includes a driving circuit. When the detection control unit 50 is composed of a first comparator U1 and a second comparator U2, the driving circuit is electrically connected to the first output end of the first comparator U1 and the second output end of the second comparator U2, respectively; the driving circuit can drive and block the third switch S3 or the fourth switch S4 according to the first control signal and the second control signal; when the detection control unit 50 is composed of a third comparator, the driving circuit is electrically connected to the third output end of the third comparator U3. At this time, the driving circuit can drive and block the third switch S3 and the fourth switch S4 according to the control signal of the third output end of the third comparator U3.

[0097] In some embodiments, the detection control unit 50 also includes an isolation circuit; wherein the isolation circuit is arranged between the driving circuit and the first comparator U1, and the driving circuit and the first comparator U1 do not share a common ground; or / and the isolation circuit is arranged between the driving circuit and the second comparator U2, and the driving circuit and the second comparator U2 do not share a common ground; or, the isolation circuit is arranged between the driving circuit and the third comparator, and the driving circuit and the third comparator do not share a common ground.

[0098] Specifically, by setting an isolation circuit, signal transmission between circuits with different potentials can be achieved. Taking the detection control unit 50 including the first comparator U1 and the second comparator U2 as an example, when the driving circuit and the ground terminal of the first comparator U1 are not in common, the isolation circuit is arranged between the driving circuit and the first comparator U1 to transmit the first control signal to the driving circuit side; when the driving circuit and the ground terminal of the second comparator U2 are not in common, the isolation circuit is arranged between the driving circuit and the second comparator U2 to transmit the second control signal to the driving circuit side. Taking the detection control unit 50 including the third comparator U3 as an example, when the driving circuit and the ground terminal of the third comparator U3 are not in common, the isolation circuit is arranged between the driving circuit and the third comparator U3 to transmit the control signal to the driving circuit side.

[0099] In some embodiments, Fig.14 and Fig.15 As shown, the totem pole power factor correction circuit can be a multi-phase interleaved parallel circuit.

[0100] In this embodiment, Fig.14 In the totem pole power factor correction circuit, the detection control unit 50 is composed of a first comparator U1 and a second comparator U2. Fig.15 The detection control unit 50 in the totem pole power factor correction circuit is composed of a third comparator U3. Under the conditions of these two cases, the totem pole power factor correction circuit also includes a third bridge arm 60 and a second inductor L2. The third bridge arm 60 is connected in parallel with the first bridge arm 10. The third bridge arm 60 includes a fifth switch S5 and a sixth switch S6 connected in series. A fifth connection point E is formed between the fifth switch S5 and the sixth switch S6. The fifth connection point E is electrically connected to the second connection point B. The second inductor L2 is electrically connected between the second connection point B and the fifth connection point E. Among them, the first bridge arm 10 and the third bridge arm 60 work alternately. At the same time, when the third bridge arm 60 is working, the detection control unit 50 can turn off the fifth switch S5 and the sixth switch S5 while turning off the third switch S3 and the fourth switch S4.

[0101] In some embodiments, the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5 and the sixth switch S6 can be any one of but not limited to MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), GaN (Gallium Nitride) switch tube or SiC (Silicon Carbide) switch tube.

[0102] In summary, in the totem pole power factor correction circuit provided by the present application, by additionally adding a sampling unit 40 and a detection control unit 50 in the circuit, the sampling unit 40 is composed of a first sampling resistor Rs1 and a second sampling resistor Rs2, the first sampling resistor Rs1 is arranged between the first diode Db1 in the bypass unit 30 and the first end a of the AC power supply VAC, and the second sampling resistor Rs2 is arranged between the second diode Db2 in the bypass unit 30 and the first end a of the AC power supply VAC, the detection control unit 50 can determine whether the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 exceeds a preset value, or whether the voltage across the first sampling resistor Rs1 and the second sampling resistor Rs2 in series exceeds a preset value, thereby determining that the third switch S3 or the fourth switch S4 of the polarity tube is abnormally driven, and timely outputting a control signal to drive and block the third switch S3 and / or the fourth switch S4, thereby effectively avoiding damage to components caused by the third switch S3 or the fourth switch S4 not being turned off in time, thereby improving the service life of components in the circuit and reducing the use cost.

[0103] In some embodiments, the present application further provides a power supply device, which includes the totem pole power factor correction circuit mentioned in the above embodiment. The switching power supply device can be a power adapter, a power bank, etc., which is not specifically limited in this embodiment.

[0104] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A totem pole power factor correction circuit, characterized in that: include: A first bridge arm, comprising a first switch and a second switch connected in series, wherein a connection point between the first switch and the second switch forms a first connection point; a bypass unit connected in parallel with the first bridge arm and comprising a first diode and a second diode connected in series, wherein a connection point between the first diode and the second diode forms a second connection point, and the second connection point is electrically connected to a first end of an AC power source; a first inductor, electrically connected between the first connection point and the second connection point; a second bridge arm connected in parallel with the first bridge arm and comprising a third switch and a fourth switch connected in series, wherein a connection point between the third switch and the fourth switch forms a third connection point, and the third connection point is electrically connected to a second end of the AC power supply; A sampling unit, comprising a first sampling resistor and a second sampling resistor, wherein the first sampling resistor is electrically connected between the second connection point and the anode of the first diode, and the second sampling resistor is electrically connected between the second connection point and the cathode of the second diode; a detection control unit, electrically connected to both ends of the first sampling resistor and both ends of the second sampling resistor respectively; when the voltage across the first sampling resistor is greater than a preset first voltage, or less than the first voltage, the detection control unit outputs a control signal to drive and block the third switch or the fourth switch; When the voltage across the second sampling resistor is greater than a preset second voltage, or less than the second voltage, the detection control unit outputs the control signal to drive and block the third switch or the fourth switch; or The detection control unit is electrically connected between the anode of the first diode and the first sampling resistor, and between the cathode of the second diode and the second sampling resistor. When the voltage across the first sampling resistor and the second sampling resistor in series is greater than or less than a preset third voltage, the detection control unit outputs the control signal to drive and block the third switch and the fourth switch.

2. The totem pole power factor correction circuit according to claim 1, characterized in that: The detection control unit includes a first comparator and a second comparator, and the control signal includes a first control signal and a second control signal; The first comparator includes a first input terminal, a second input terminal and a first output terminal, the first input terminal receives the voltage across the first sampling resistor, the second input terminal receives the first voltage, and the first output terminal is used to output the first control signal to drive and block the third switch or the fourth switch; The second comparator includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal receives the voltage across the second sampling resistor, the fourth input terminal receives the second voltage, and the second output terminal is used to output the second control signal to drive and block the third switch or the fourth switch.

3. The totem pole power factor correction circuit according to claim 2, characterized in that: The first comparator further includes a first ground terminal, and the second comparator further includes a second ground terminal; the first ground terminal and the second ground terminal are respectively grounded to the first terminal of the AC power supply.

4. The totem pole power factor correction circuit according to claim 2, characterized in that: The first output terminal is used to output the first control signal to drive and block the third switch; the second output terminal is used to output the second control signal to drive and block the fourth switch.

5. The totem pole power factor correction circuit according to claim 2, characterized in that: The control signal also includes a third control signal, and the third control signal is generated by performing a logic operation on the first control signal and the second control signal.

6. The totem pole power factor correction circuit according to claim 1, characterized in that: The detection control unit includes a third comparator; The third comparator includes a fifth input terminal, a sixth input terminal and a third output terminal, the fifth input terminal receives the voltage across the first sampling resistor and the second sampling resistor in series, the sixth input terminal receives the third voltage, and the third output terminal is used to output a control signal to drive and block the third switch and the fourth switch.

7. The totem pole power factor correction circuit according to claim 6, characterized in that: The third comparator further includes a third ground terminal, and the third ground terminal is shared with the first terminal of the AC power source.

8. The totem pole power factor correction circuit according to claim 2 or 6, characterized in that: The detection control unit also includes a driving circuit; Wherein, the driving circuit receives an output control signal to drive and block the third switch and / or the fourth switch; The driving circuit is electrically connected to the first output terminal of the first comparator and the second output terminal of the second comparator respectively; or the driving circuit is electrically connected to the third output terminal of the third comparator.

9. The totem pole power factor correction circuit according to claim 8, characterized in that: The detection control unit also includes an isolation circuit; Among them, the isolation circuit is arranged between the driving circuit and the first comparator, and the driving circuit and the first comparator do not share a common ground; or / and the isolation circuit is arranged between the driving circuit and the second comparator, and the driving circuit and the second comparator do not share a common ground; or the isolation circuit is arranged between the driving circuit and the third comparator, and the driving circuit and the third comparator do not share a common ground.

10. The totem pole power factor correction circuit according to claim 1, characterized in that: The control signal is a high level signal or a low level signal.

11. The totem pole power factor correction circuit according to claim 1, characterized in that: The first switch, the second switch, the third switch and the fourth switch are any one of a MOSFET switch tube, an IGBT switch tube, a GaN switch tube or a SiC switch tube.

12. The totem pole power factor correction circuit according to claim 1, characterized in that: The Teng-pole power factor correction circuit is a multi-phase interleaved parallel circuit.

13. The totem pole power factor correction circuit according to claim 12, characterized in that: The teng-pole power factor correction circuit also includes a third bridge arm and a second inductor; The third bridge arm is connected in parallel with the first bridge arm, the third bridge arm includes a fifth switch and a sixth switch connected in series, a fifth connection point is formed between the fifth switch and the sixth switch, and the second inductor is electrically connected between the second connection point and the fifth connection point.

14. The totem pole power factor correction circuit according to claim 13, characterized in that: The first bridge arm and the third bridge arm work alternately.

15. A power supply device, characterized in that: A totem pole power factor correction circuit comprising any one of claims 1-14.

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