A DC boost converter

Abstract

The present application provides a DC boost conversion device, which relates to the field of power electronics technology. The DC boost conversion device may include: a controller and a boost converter, and the boost converter includes: a switch module, a charge and discharge module, a first switch, a boost module and a voltage stabilizing module; the switch module is used to access the input voltage; one end of the charge and discharge module is respectively connected to the switch module and the first end of the first switch, and the other end of the charge and discharge module is connected to the switch module; the second end of the first switch is connected to one end of the boost module, and the third end of the first switch is connected to the controller; the other end of the boost module is connected to the voltage stabilizing module; the controller is connected to the switch module, and the controller is used to output a control signal to the switch module and the first switch to control the opening and closing of the switch module and the first switch, so that the boost converter outputs the boosted output voltage. In this way, the performance of the boost converter in the DC boost conversion device can be improved.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a direct current boost conversion device. Background Art

[0002] The power management system is an indispensable part of the integrated circuit. The DC boost converter in the power management system can boost the power supply voltage to a fixed voltage value and provide operating voltage for various types of loads.

[0003] At present, a DC boost converter may include multiple switches, flying capacitors, and inductors, wherein the flying capacitors are directly connected to the inductors. Based on the requirement of low power consumption, the circuit components in the DC boost converter can be connected in the above manner to enable the DC boost converter to operate in a discontinuous conduction mode (DCM).

[0004] However, when the DC boost converter operates in DCM, the charging time of the flying capacitor during a switching cycle is limited, which in turn affects the performance of the DC boost converter. Summary of the invention

[0005] The purpose of the present application is to provide a DC boost conversion device to improve the performance of the boost converter in the DC boost conversion device in view of the above-mentioned deficiencies in the prior art.

[0006] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0007] The embodiment of the present application provides a DC boost conversion device including: a controller and a boost converter, wherein the boost converter includes: a switch module, a charge and discharge module, a first switch, a boost module and a voltage stabilizing module;

[0008] The switch module is used to access the input voltage;

[0009] One end of the charging and discharging module is connected to the switch module and the first end of the first switch respectively, and the other end of the charging and discharging module is connected to the switch module;

[0010] The second end of the first switch is connected to one end of the boost module, and the third end of the first switch is connected to the controller;

[0011] The other end of the boost module is connected to the voltage stabilizing module;

[0012] The controller is connected to the switch module, and is used to output a control signal to the switch module and the first switch to control the switching of the switch module and the first switch, so that the boost converter outputs a boosted output voltage.

[0013] Optionally, the first switch is a three-terminal transistor.

[0014] Optionally, the switch module includes: a second switch, a third switch and a fourth switch;

[0015] The first end of the second switch is used to access the input voltage, the second end of the second switch is respectively connected to the first end of the first switch and one end of the charging and discharging module, and the third end of the second switch is connected to the controller;

[0016] The first end of the third switch is used to access the input voltage, the second end of the third switch is respectively connected to the first end of the fourth switch and the other end of the charge and discharge module, and the third end of the third switch is connected to the controller;

[0017] The first end of the fourth switch is respectively connected to the second end of the third switch and the other end of the charge and discharge module, the second end of the fourth switch is grounded, and the third end of the fourth switch is connected to the controller.

[0018] Optionally, the second switch, the third switch and the fourth switch are three-terminal transistors respectively.

[0019] Optionally, the charging and discharging module includes: a first capacitor.

[0020] Optionally, the boost module includes: an inductor.

[0021] Optionally, the voltage stabilization module includes: a second capacitor.

[0022] Optionally, the DC boost conversion device further includes: a voltage detection module;

[0023] The voltage detection module is connected to the first end, the second end of the first switch and the controller respectively.

[0024] Optionally, the controller is used to detect a voltage difference between a first end and a second end of the first switch through the voltage detection module, and output a control signal indicating disconnection to the first switch when the voltage difference reaches a first preset threshold.

[0025] Optionally, the controller includes a clocked comparator, a dual clock oscillator, a feedback resistor network and a switch control module;

[0026] The first switch, the second switch, the third switch and the fourth switch respectively include a plurality of switch tubes;

[0027] The input end of the feedback resistor network is connected to the output end of the boost converter, and the feedback resistor network is used to convert the output voltage of the boost converter into a feedback voltage signal;

[0028] The input end of the clock-controlled comparator is connected to the output end of the feedback resistor network, and the clock-controlled comparator is used to generate a clock selection signal according to the received feedback voltage signal and the reference voltage;

[0029] The input end of the dual clock oscillator is connected to the output end of the clock control comparator, and the dual clock oscillator is used to determine whether to turn on the fast clock in the dual clock oscillator according to the clock selection signal, and when the fast clock is turned on, record the working cycle corresponding to the fast clock from the on time to the off time period;

[0030] The switch control module is connected to the output end of the clock-controlled comparator and the output end of the dual-clock oscillator. The switch control module is used to output switch size control signals to the first switch, the second switch, the third switch and the fourth switch respectively according to the clock selection signal and the working cycle corresponding to the previous start of the fast clock, so as to control the opening and closing of each switch tube in the first switch, the second switch, the third switch and the fourth switch, so that the boost converter outputs the boosted output voltage.

[0031] Optionally, the feedback resistor network includes: a fifth switch, a sixth switch, a seventh switch, a first resistor, a second resistor, and a third capacitor;

[0032] One end of the fifth switch is connected to the output end of the boost converter, the other end of the fifth switch is connected to one end of the first resistor, a node where the other end of the first resistor and one end of the second resistor are connected is connected to one end of the sixth switch, the other end of the fifth switch is respectively connected to the input end of the clocked comparator and one end of the third capacitor, and the other end of the third capacitor is grounded;

[0033] The other end of the second resistor is connected to one end of the seventh switch, and the other end of the seventh switch is grounded;

[0034] The input end of the clock-controlled comparator is also connected to the output end of the dual-clock oscillator, and the clock-controlled comparator is also used to compare the feedback voltage signal and the reference voltage according to the working cycle of the fast clock or the clock frequency of the slow clock;

[0035] The output end of the dual-clock oscillator is also connected to the fifth switch, the sixth switch and the seventh switch, and the dual-clock oscillator is also used to control the opening and closing of the fifth switch, the sixth switch and the seventh switch according to the working cycle of the fast clock or the working cycle of the slow clock.

[0036] The beneficial effects of this application are:

[0037] An embodiment of the present application provides a DC boost conversion module, which may include: a controller and a boost converter, the boost converter including: a switch module, a charge and discharge module, a first switch, a boost module and a voltage stabilizing module; the switch module is used to access an input voltage; one end of the charge and discharge module is respectively connected to the switch module and the first end of the first switch, and the other end of the charge and discharge module is connected to the switch module; the second end of the first switch is connected to one end of the boost module, and the third end of the first switch is connected to the controller; the other end of the boost module is connected to the voltage stabilizing module; the controller is connected to the switch module, and the controller is used to output a control signal to the switch module and the first switch to control the opening and closing of the switch module and the first switch, so that the boost converter outputs a boosted output voltage.

[0038] By adopting the DC boost conversion device provided in the embodiment of the present application, the modules composed of the circuit devices in the boost converter in the DC boost conversion device are connected according to the above-mentioned connection method, and combined with the controller in the DC boost conversion device to control the switch module and the first switch in the boost converter in each switching cycle, the charging time of the charge and discharge module in the boost converter can be extended, so that the charge and discharge module has more charge capacity. Since the charge capacity of the charge and discharge module is positively correlated with the performance of the boost module, the performance of the boost converter can be improved when the charge and discharge module has more charge capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 A schematic diagram of the structure of a DC boost converter provided in an embodiment of the present application;

[0041] Figure 2 A schematic diagram of the structure of another DC boost converter provided in an embodiment of the present application;

[0042] Figure 3 A topological structure of a DC boost converter provided in an embodiment of the present application;

[0043] Figure 4 A schematic diagram of current flow when a boost converter provided by an embodiment of the present application is in a first state;

[0044] Figure 5 A schematic diagram of current flow when a boost converter provided by an embodiment of the present application is in a second state;

[0045] Figure 6 A schematic diagram of current flow when a boost converter provided by an embodiment of the present application is in a third state;

[0046] Figure 7 A change in current flowing through an inductor in a switching cycle provided by an embodiment of the present application;

[0047] Figure 8 A schematic diagram of recording the startup time of a boost converter provided in an embodiment of the present application;

[0048] Fig. 9 A schematic structural diagram of another DC boost converter device provided in an embodiment of the present application;

[0049] Fig.10 A schematic diagram of the structure of a DC boost converter provided in an embodiment of the present application;

[0050] Fig.11 A schematic diagram of the structure of a feedback resistor network provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0052] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0053] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0054] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] Figure 1 This is a schematic diagram of the structure of a DC boost converter provided in an embodiment of the present application. Figure 1 As shown, the DC boost conversion device 100 includes: a controller 10 and a boost converter 20 , and the boost converter 20 includes: a switch module 101 , a charge and discharge module 102 , a first switch 103 , a boost module 104 and a voltage stabilizing module 105 .

[0056] The switch module 101 is used to access the input voltage; one end of the charge and discharge module 102 is respectively connected to the switch module 101 and the first end of the first switch 103, and the other end of the charge and discharge module 102 is connected to the switch module 101; the second end of the first switch 103 is connected to one end of the boost module 104, and the third end of the first switch 103 is connected to the controller 10; the other end of the boost module 104 is connected to the voltage stabilizing module 105.

[0057] The controller 10 is connected to the switch module 101 , and is used to output a control signal to the switch module 101 and the first switch 103 to control the switching of the switch module 101 and the first switch 103 , so that the boost converter 20 outputs a boosted output voltage.

[0058] Among them, the boost converter 20 is a DC / DC converter (Direct current-Direct current converter), which refers to a device that converts electric energy of one voltage value into electric energy of another voltage value in a DC circuit. It can be widely used in integrated circuits in the fields of electric vehicles, new energy power generation, uninterruptible power supplies, power management systems, etc. It should be noted that this application does not limit the specific application field of the boost converter.

[0059] The connection relationship of each module in the boost converter 20 is described below. Specifically, the switch module 101 in the boost converter 20 can be connected to the input voltage (Vin), and the specific value of the input voltage (Vin) can be set according to actual needs, such as 2V, 3V. The charge and discharge module 102 in the boost converter 20 is a module composed of circuit devices for charging and discharging. According to the charge and discharge characteristics of the charge and discharge module 102 in the boost converter 20, the end connected to one end of the switch module 101 and the first end of the first switch 103 is called the positive terminal, and the end connected to the other end of the switch module 101 is called the negative terminal.

[0060] The boost module 104 is a module composed of circuit devices that can boost the input voltage (Vin) connected to the switch module 101, and is connected between the second end of the first switch 103 and the voltage stabilizing module 105. The node M where the boost module 104 and the voltage stabilizing module 105 are connected can be connected to the load 106. The voltage stabilizing module 105 can make the voltage at the output end of the boost converter 20 reach the target voltage after boosting and keep the target voltage stable when the voltage at the output end of the boost converter 20 drops, and the load 106 can perform corresponding work based on the target voltage.

[0061] The node M may be connected to the controller 10, and is used to feed back the boosted output voltage of the boost converter 20 to the controller 10. The controller 10 generates a control signal based on the boosted output voltage of the boost converter 20 to control the opening and closing of the switch module 101 and the first switch 103. Specifically, the controller 10 may be connected to the switch module 101 and the first switch 103, respectively, and specifically connected to the third end of the first switch 103. The controller 10 may be used to send a disconnection instruction (control signal) to the switch module 101 and the first switch 103, respectively, so that the switch module 101 and the first switch 103 are opened (conducted) or disconnected.

[0062] The boost converter 20 can operate in a discontinuous conduction mode (DCM). When the boost converter 20 operates in DCM, the controller 10 can convert the boosted output voltage of the boost converter 20 into a PWM (Pulse width modulation) signal, and send a control instruction to each switch in the boost converter 20 based on the PWM signal. Under the control of each switching cycle of the controller 10, the switch module 101 and the first switch 103 in the boost converter 20 can make the boost converter 20 in three states when operating in DCM, wherein the first state is the charging stage of the boost module 104, the second state is the discharging stage of the boost module 104, and the third state is the stage where the current on the boost module 104 is zero. Then the controller 10 can make the first switch 103 in the on state in the first state and the second state, and the controller 10 can make the first switch 103 in the off state in the third state, so that when the boost converter 20 is in the second state and the third state, the charging and discharging module 102 is in the charging state.

[0063] It should be noted that Figure 1 It is a connection topology circuit diagram of a module composed of various circuit components in the boost converter 20, and is not intended to be a display of actual physical connection relationships.

[0064] Using the above Figure 1 The DC boost conversion device shown may include: a controller and a boost converter, the boost converter includes: a switch module, a charge and discharge module, a first switch, a boost module and a voltage stabilizing module; the switch module is used to access the input voltage; one end of the charge and discharge module is respectively connected to the switch module and the first end of the first switch, and the other end of the charge and discharge module is connected to the switch module; the second end of the first switch is connected to one end of the boost module, and the third end of the first switch is connected to the controller; the other end of the boost module is connected to the voltage stabilizing module; the controller is connected to the switch module, and the controller is used to output a control signal to the switch module and the first switch to control the opening and closing of the switch module and the first switch, so that the boost converter outputs a boosted output voltage.

[0065] By adopting the DC boost conversion device provided in the embodiment of the present application, a first switch is added to the boost converter in the DC boost conversion device, and the module composed of various circuit devices in the boost converter and the first switch are connected according to the above-mentioned connection method, and combined with the controller in the DC boost conversion device to control the switch module and the first switch in the boost converter in each switching cycle, the charging time of the charge and discharge module in the boost converter can be extended, so that the charge and discharge module has more charge capacity. Since the charge capacity of the charge and discharge module is positively correlated with the performance of the boost module, the performance of the boost converter can be improved when the charge and discharge module has more charge capacity.

[0066] Optionally, the first switch 103 mentioned above may be a three-terminal transistor, specifically a metal oxide semiconductor field effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET tube), a bipolar junction transistor (Bipolar Junction Transistor, BJT), etc. It should be noted that the present application does not limit the specific form of the three-terminal transistor. Here, the first switch is a MOSFET tube as an example for explanation. The first end of the first switch 103 can be called a drain, which is respectively connected to one end of the switch module 101 and the charge and discharge module 102; the second end of the first switch 103 can be called a source, which is connected to one end of the boost module 104; the third end of the first switch 103 can be called a gate, which is connected to the controller 10.

[0067] Figure 2 This is a schematic diagram of the structure of another DC boost converter provided in an embodiment of the present application. Figure 2 As shown, the switch module 101 may include a second switch 201 , a third switch 202 , and a fourth switch 203 .

[0068] The first end of the second switch 201 is used to connect to the input voltage, the second end of the second switch 201 is connected to the first end of the first switch 103 and one end of the charge and discharge module 102 respectively, and the third end of the second switch 201 is connected to the controller 10;

[0069] The first end of the third switch 202 is used to access the input voltage, the second end of the third switch 202 is respectively connected to the first end of the fourth switch 203 and the other end of the charge and discharge module 102, and the third end of the third switch 202 is connected to the controller 10; the first end of the fourth switch 203 is respectively connected to the second end of the third switch 202 and the other end of the charge and discharge module 102, the second end of the fourth switch 203 is grounded, and the third end of the fourth switch 203 is connected to the controller 10.

[0070] Among them, the control signals sent by the controller 10 to the first switch 103, the second switch 201, the third switch 202 and the fourth switch 203 are represented by S1, S2, S3, and S4 respectively. The controller 10 can send corresponding opening and closing instructions to the first switch 103, the second switch 201, the third switch 202 and the fourth switch 203 in each switching cycle, so that the boost converter 20 is in the three states mentioned above when working in each switching cycle.

[0071] In an achievable embodiment, the first switch 103, the second switch 201, the third switch 202 and the fourth switch 203 mentioned above may all be three-terminal transistors, specifically MOSFET tubes, wherein the first switch 103, the second switch 201 and the third switch 202 may all be P-channel MOSFET tubes, and the fourth switch 203 may be an N-channel MOSFET tube. The first end, the second end and the third end of the second switch 201 may be respectively referred to as the drain, the source and the gate, the first end, the second end and the third end of the third switch 202 may be respectively referred to as the source, the drain and the gate, and the first end, the second end and the third end of the fourth switch 203 may be respectively referred to as the drain, the source and the gate. The charge and discharge module 102 may include a first capacitor C f , the first capacitor C f Usually called a flying capacitor, the boost module 104 may include an inductor L, and the voltage stabilizing module 105 may include a second capacitor C 0 .

[0072] In the following description, the charging and discharging module 102 is used as the first capacitor C f , the boost module 104 is an inductor L, and the voltage stabilizing module 105 is a second capacitor C 0 The circuit structure of the boost converter 20 is described from the perspective of FIG.

[0073] Figure 3 A topological structure of a DC boost converter device provided in an embodiment of the present application. Figure 3 As shown, the first switch 103, the second switch 201, the third switch 202 and the fourth switch 203 are Figure 3 In the diagram, K1, K2, K3, and K4 are used to represent the charging and discharging module 102 (the first capacitor) and C f The boost module 104 (inductor) is represented by the symbol L, and the voltage stabilizing module 105 (second capacitor) is represented by the symbol C. 0 Symbol indicates that the load 106 is R Load Symbolic representation.

[0074] The gates corresponding to the first switch (K1), the second switch (K2), the third switch (K3), and the fourth switch (K4) can be connected to the controller 10 respectively. The controller 10 can control the opening and closing of the first switch (K1), the second switch (K2), the third switch (K3), and the fourth switch (K4) based on the control signals S1, S2, S3, and S4, so that the first switch (K1), the second switch (K2), the third switch (K3), and the fourth switch (K4) are in the on or off state. The connection relationship between the source and drain corresponding to each switch and other circuit components in the boost converter 20 can refer to the connection relationship between the first end and the second end of each switch and other circuit components, which will not be described here. Figure 3 As can be seen from the figure, the ground terminal may include the source of the fourth switch (K4), the second capacitor C 0 One end of the load R Load one end.

[0075] It should be noted that when the DC boost converter 100 needs to boost an input voltage to a target voltage with a fixed voltage value under DCM, the controller 10 needs to go through multiple switching cycles to make the voltage output by the boost converter 20 reach the target voltage. The controller 10 can put the boost converter 20 in three states in each switching cycle. In each state, Figure 3 The first switch (K1), the second switch (K2), the third switch (K3), and the fourth switch (K4) all correspond to a set of disconnection instructions. T1, T2, and T3 can be used to represent the time when the boost converter 20 is in the three states respectively.

[0076] The following takes a switching cycle as an example to explain the on / off state of each switch and the current flow direction in the circuit when the boost converter 20 is in the three states respectively.

[0077] Figure 4 A schematic diagram of current flow when a boost converter is in a first state provided by an embodiment of the present application. Figure 4 As shown, the controller 10 can send a turn-on instruction to the first switch (K1) and the third switch (K3), and send a turn-off instruction to the second switch (K2) and the fourth switch (K4). Figure 4 The shaded state indicates that the MOSFET is in the cut-off state (disconnected state), and the dotted line indicates the current flow direction. Figure 4 It can be seen from the figure that under the control of the controller 10 on each switch as described above, the first capacitor (C f ) is in the discharge state, the inductor (L) is in the charge state, and the second capacitor (C 0 ) is in the charging state, where the current flowing through the inductor (L) is Figure 4In the first state (T1), IL gradually increases. Figure 4 In, use I in Indicates input voltage (V in ) corresponding to the current, I cf Represents the first capacitor (C f ) is the current in the branch where it is located, expressed as I co Represents the second capacitance (C 0 ) is the current in the branch where it is located, expressed as I Load Indicates load (R Load ) is the current in the branch where V OUT represents the voltage outputted from the output terminal of the boost converter 20; V L Indicates the voltage across the voltage (L), which can be expressed as V Cf Represents the first capacitor (C f )The voltage across the terminals.

[0078] Figure 5 A schematic diagram of current flow when a boost converter is in a second state provided by an embodiment of the present application. Figure 5 As shown, the controller 10 can send a turn-on instruction to the first switch (K1), the second switch (K2) and the fourth switch (K4), and send a turn-off instruction to the third switch (K3). Figure 5 The shaded state indicates that the MOSFET is in the cut-off state (disconnected state), and the dotted line indicates the current flow direction. Figure 5 It can be seen from the figure that under the control of the controller 10 on each switch as described above, the first capacitor (C f ) is in the charging state, the inductor (L) is in the discharging state, and the second capacitor (C 0 ) is in the charging state, where the current I flowing through the inductor (L) L In the second state (T2), it gradually decreases. For other reference numbers, please refer to Figure 4 The description in will not be explained here.

[0079] Figure 6 A schematic diagram of current flow when a boost converter is in a third state provided by an embodiment of the present application. Figure 6 As shown, the controller 10 can send a conduction instruction to the second switch (K2) and the fourth switch (K4), and send a disconnection instruction to the first switch (K1) and the third switch (K3). Figure 6 The shaded state in the figure indicates that the MOSFET is in the cut-off state (off state) and no current flows through the inductor (L). The dotted line can be used to indicate the current flow direction. Figure 6 It can be seen from the figure that under the control of the controller 10 on each switch as described above, the first capacitor (Cf ) is in the charging state, and the inductor (L) is also in the discharging state, but the current I flowing through the inductor (L) is L is 0, that is, the current I L In the third state (T3), the second capacitance (C 0 ) is in the discharge state, which can make the voltage output by the boost converter output (V OUT ) to reach the target voltage after boosting and to keep the target voltage stable after reaching it. For other labels, please refer to Figure 4 The description in will not be explained here.

[0080] It should be noted that due to the charging capacity of the inductor (L) and the first capacitor (C f ), so the performance of the boost converter 20 depends on the charge capacity of the first capacitor (C f ) of the charge capacity, the first capacitor (C f ) has a larger charge capacity, the more the performance of the boost converter 20 can be improved.

[0081] from Figure 4-Figure 6 It can be seen that the first capacitor (C f ) is in the charging state in the second state (T1) and the third state (T3), then the first capacitor (C f ) voltage in each switching cycle (V Cf ):

[0082]

[0083] Among them, V 0 is the initial voltage value of the capacitor in each cycle, V in is the input voltage.

[0084] Since the first capacitor (C f ) can continue to be charged in the third state (T3), so that the first capacitor (C f )The voltage across the Cf ) is closer to the input voltage (V in That is, the first capacitor (C f ) can maintain the maximum voltage across the two ends, thus enabling the boost converter to have the maximum output power.

[0085] According to the current I flowing through the inductor (L) L The changes in each switching cycle can be Figure 7 for display. Figure 7 The embodiment of the present application provides a change in the current flowing through an inductor in a switching cycle. In order to more clearly illustrate the performance of the boost converter in the present application, the inductor current (IL ) is used as a reference, and the first capacitor (C f ) respectively in the three states corresponding to the current (I Cf ) changes with the flying capacitor (equivalent to the first capacitor (C f )) The corresponding current (I') in the three states Cf ) is compared with the change of the first capacitor (C f ) continues to be charged in the third stage (T3), so the first capacitor (C f ) corresponds to the voltage (V Cf ) is greater than the voltage (V′) corresponding to the flying capacitor in the traditional solution Cf ), and thus the first capacitor (C f ) corresponds to the current (I Cf )The maximum value (F) is smaller than the current (I') corresponding to the flying capacitor in the traditional technology Cf ) maximum value (G). That is, the boost converter in the present application generates less loss during the boost process, that is, the efficiency of converting the input voltage into the target voltage is improved.

[0086] It should be noted that when the boost converter performs boosting, it can be divided into two stages, one is the startup stage, and the other is the stabilization stage. The startup stage refers to the process of increasing the input voltage to the target voltage, and the stabilization stage refers to keeping the output voltage at the target voltage.

[0087] From the perspective of boost converter startup, since the first capacitor (C f ) The charging time is longer, so sufficient voltage can be provided to the load more quickly, that is, the startup time is reduced. In order to more clearly illustrate the performance of the boost converter in this application, the startup time of the boost converter in this application is compared with the startup time of the traditional boost converter. The comparison results can be used Figure 8 for display. Figure 8 A schematic diagram of recording the startup time of a boost converter provided in an embodiment of the present application. Figure 8 As shown, for example, the input voltage of 2V is boosted (V in ) is the target voltage (V out ),from Figure 8 It can be seen that the startup time of the boost converter in the present application is 66 μs, and the startup time of the traditional boost converter is 103.6 μs. It can be seen that the startup time of the boost converter in the present application is reduced by 36% compared with the startup time of the traditional boost converter.

[0088] Fig. 9This is a structural diagram of another DC boost converter provided in an embodiment of the present application. Fig. 9 As shown, the DC boost converter 100 may further include: a voltage detection module 900 , which is connected to the first end and the second end of the first switch 103 and the controller 10 , respectively.

[0089] The controller 10 is used to detect the voltage difference between the first end and the second end of the first switch 103 through the voltage detection module 900, and output a control signal indicating disconnection to the first switch 103 when the voltage difference reaches a first preset threshold.

[0090] The voltage detection module 900 may be specifically an inductor zero current detector. The third state mentioned above refers to a state where the current flowing through the boost module 104 (inductor L) is 0, that is, when the current through the boost module 104 is 0, the boost converter 20 needs to be in the third state, and the current flowing through the boost module 104 can be indirectly obtained through the voltage difference between the first end and the second end of the first switch 103. The controller 10 detects the voltage difference between the first end and the second end of the first switch 103 through the voltage detection module 900. When the voltage difference is 0, it means that the current flowing through the boost module 104 is 0, and the first preset threshold is 0 here.

[0091] Since the first switch 103 and the boost module 104 are in a series relationship, the detected current value can be made closer to the current flowing through the inductor L, that is, the accuracy of detecting the current zero crossing point (Zero Current Detection, ZCD) can be improved.

[0092] Fig.10 A schematic diagram of the structure of a DC boost converter provided in an embodiment of the present application is shown in FIG. Fig.10 As shown, the controller 10 in the DC boost converter includes a clocked comparator 1001 , a dual clock oscillator 1002 , a feedback resistor network 1003 and a switch control module 1004 .

[0093] The first switch 103 (K1), the second switch 201 (K2), the third switch 202 (K3) and the fourth switch 203 (K4) respectively include multiple switch tubes; the input end of the feedback resistor network 1003 is connected to the output end of the boost converter 20, and the feedback resistor network 1003 is used to convert the output voltage of the boost converter 20 into a feedback voltage signal; the input end of the clocked comparator 1001 is connected to the output end of the feedback resistor network 1003, and the clocked comparator 1001 is used to generate a clock selection signal according to the received feedback voltage signal and the reference voltage.

[0094] The input end of the dual clock oscillator 1002 is connected to the output end of the clock control comparator 1001. The dual clock oscillator 1002 is used to determine whether to turn on the fast clock in the dual clock oscillator 1002 according to the clock selection signal, and when the fast clock is turned on, record the working cycle corresponding to the fast clock from the on-time to the off-time period.

[0095] The switch control module 1004 is connected to the output end of the clock-controlled comparator 1001 and the output end of the dual-clock oscillator 1002, and is used to output switch size control signals to the first switch 103 (K1), the second switch 201 (K2), the third switch 202 (K3) and the fourth switch 203 (K4) according to the clock selection signal and the working cycle corresponding to the previous start of the fast clock, so as to control the opening and closing of each switch tube in the first switch 103 (K1), the second switch 201 (K2), the third switch 202 (K3) and the fourth switch 203 (K4), so that the boost converter 20 outputs the boosted output voltage.

[0096] refer to Fig.10 As shown, the first switch 103 (K1), the second switch 201 (K2), the third switch 202 (K3) and the fourth switch 203 (K4) may include multiple switch tubes respectively, such as the first switch 103 (K1) may include switch tube K1-1, switch tube K1-2 and switch tube K1-3, and other switches are similar. It should be noted that the present application does not limit the number of switch tubes included in each switch. Among them, the switch tube in each switch is specifically a three-terminal transistor (such as MOSFET). It should be noted that the type of switch tube included in each switch is consistent. For example, the first switch 103 (K1) is a P-channel MOSFET tube, then the switch tubes included in the first switch 103 (K1) are all P-channel MOSFET tubes, and the switch tubes included in each switch are connected in parallel. The specific connection method of each switch tube can refer to the relevant records in the field, and will not be described here. It can be understood that the connection relationship between the various devices in the above-mentioned boost converter 20 is described based on the dimension of a switch tube included in the switch. Therefore, the connection relationship between the three levels (source, drain, and gate) of each switch tube in each switch and other devices in the boost converter 20 can be obtained by referring to the above description, which will not be explained here.

[0097] Continue to refer Fig.10 As shown, the clocked comparator 1001 may include three input terminals, which may be used to input the feedback voltage signal (V FB ), a reference voltage, and a signal output from the output terminal of the dual clock oscillator 1002. in ) generates a reference voltage (V REF1 ), generally, the reference voltage (VREF1 ) is half of the target voltage after boosting. The feedback voltage signal (V FB ) is the output voltage (V OUT ) is the voltage signal obtained after voltage reduction processing.

[0098] The clocked comparator 1001 operates at a voltage V DDL Under this condition, the feedback voltage signal (V FB ) and the reference voltage (V REF1 ) for comparison, and generates a clock selection signal (V EN ), it should be noted that, Fig.10 V EN Signal and V EN-INV The signals are two opposite signals, that is, the clock selection signal (V EN ) is 1, then V EN-INV Specifically, when the feedback voltage signal (V FB ) is greater than the reference voltage (V REF1 ), the clock selection signal (V EN ) is 1, when the feedback voltage (V FB ) is less than or equal to the reference voltage (V REF1 ), the clock selection signal (V EN ) level is 0.

[0099] The input terminal of the dual clock oscillator 1002 inputs the clock selection signal (V EN ), the clock selection signal (V EN ) is 1, only the slow clock in the dual clock oscillator 1002 is working. E N) is 0, the fast clock in the dual clock oscillator 1002 is turned on. When the fast clock is turned on, the fast clock can work according to the preset cycle. FB ) is greater than the reference voltage (V REF1 ), that is, the clock selection signal (V EN ) changes from 0 to 1, the fast clock in the dual clock oscillator 1002 is turned off, and the dual clock oscillator 1002 can count the working cycles of the fast clock from the start to the shutdown period, and the number of working cycles can be represented by Nt. In another achievable embodiment, the working cycle of the fast clock from the start to the shutdown period can also be counted by the detection unit in the switch control module 1004, which is not limited in this application.

[0100] The switch control module 1004 is connected to the output end of the dual clock oscillator 1002. When the fast clock in the dual clock oscillator 1002 is turned on, the number of working cycles (N) corresponding to the fast clock on-to-off period obtained when the fast clock was turned on last time can be recorded. t-1 ) is sent to the switch control module 1004, and the switch control module 1004 may start the fast clock according to the number of working cycles (N t-1 ) and the clock selection signal (V EN ) and (V EN-INV ) signal generates the switch size control signal.

[0101] For example, assuming that the boost converter 20 is in the first state mentioned above, the switch control module 1004 may send a switch size control signal corresponding to opening some switches to the first switch 103 (K1) and the third switch 202 (K3), and send a switch size control signal corresponding to disconnecting all switches to the second switch 201 (K2) and the fourth switch 203 (K4). Specifically, the number of switches that need to be opened in the first switch 103 (K1) and the third switch 202 (K3) is related to the number of working cycles (N) corresponding to the fast clock. The more the number of working cycles (N), the more switches that need to be opened in the first switch 103 (K1) and the third switch 202 (K3).

[0102] It can be seen that the size of each switch in the boost converter, that is, the number of switch tubes in each switch that are turned on is related to the output current at the output end of the boost converter. When the output current is small, the size of the switch becomes smaller, and when the output current is large, the size of the switch becomes larger. This can make the boost converter generate less loss during the boost process and further improve the efficiency of converting the input voltage to the target voltage.

[0103] Fig.11 A schematic diagram of a feedback resistor network provided in an embodiment of the present application is shown in FIG. Fig.11 As shown, the feedback resistor network 1003 includes a fifth switch K5, a sixth switch K6, a seventh switch K7, a first resistor R1, a second resistor R2, a third capacitor C S .

[0104] One end of the fifth switch K5 is connected to the output end of the boost converter 20, the other end of the fifth switch K5 is connected to one end of the first resistor R1, the node where the other end of the first resistor R1 and one end of the second resistor R2 are connected is connected to one end of the sixth switch K6, and the other end of the fifth switch K5 is connected to the input end of the clocked comparator 1001 and the third capacitor C S One end of the third capacitor C SThe other end of the second resistor R2 is connected to one end of the seventh switch K7, and the other end of the seventh switch K7 is grounded.

[0105] The input end of the clock-controlled comparator 1001 is also connected to the output end of the dual-clock oscillator 1002. The clock-controlled comparator 1001 is also used to compare the feedback voltage signal and the reference voltage according to the working cycle of the fast clock or the working cycle of the slow clock. The output end of the dual-clock oscillator 1002 is also connected to the fifth switch K5, the sixth switch K6 and the seventh switch K7. The dual-clock oscillator 1002 is also used to control the opening and closing of the fifth switch K5, the sixth switch K6 and the seventh switch K7 according to the working cycle of the fast clock or the clock frequency of the slow clock.

[0106] refer to Fig.10 as well as Fig.11 When the clock-controlled comparator 1001 compares the feedback voltage signal with the reference voltage is determined by the clock cycle of the slow clock or the working cycle of the fast clock in the dual-clock oscillator 1002. Specifically, when the feedback voltage signal is greater than the reference voltage, only the slow clock works at this time, and the clock-controlled comparator 1001 can compare the feedback voltage signal with the reference voltage according to the clock cycle of the slow clock. When the feedback voltage signal is less than the reference voltage, the fast clock works at this time, and the clock-controlled comparator 1001 can compare the feedback voltage signal with the reference voltage according to the working cycle of the fast clock.

[0107] According to the above description, the clocked comparator 1001 does not always need the feedback voltage output from the output end of the feedback resistor network 1003. Therefore, the opening and closing timing of each switch in the feedback resistor network 1003 can be determined according to the clock cycle of the slow clock or the working cycle of the fast clock in the dual clock oscillator 1002.

[0108] Specifically, from Fig.11 It can be seen that the feedback resistor network 1003 is equivalent to a voltage divider network. When the fast clock is not turned on, the fifth switch K5, the sixth switch K6 and the seventh switch K7 in the feedback resistor network 1003 can be controlled to be in a short-term on state according to a fixed clock frequency of the slow clock. When the fast clock is turned on, the fifth switch K5, the sixth switch K6 and the seventh switch K7 in the feedback resistor network 1003 can be controlled to be in an on state according to the working cycle corresponding to the fast clock in the on stage. In this way, the resistance values ​​of the first resistor R1 and the second resistor R2 can be reduced under the premise of ensuring that there is a small current in the feedback resistor network 1003, thereby achieving the purpose of reducing the chip area of ​​the first resistor R1 and the second resistor R2. In other words, the feedback resistor network can be miniaturized, thereby miniaturizing the DC boost converter.

[0109] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A DC boost converter, characterized in that: include: A controller and a boost converter, wherein the boost converter comprises: a switch module, a charge and discharge module, a first switch, a boost module and a voltage stabilizing module; The switch module is used to access the input voltage; One end of the charging and discharging module is connected to the switch module and the first end of the first switch respectively, and the other end of the charging and discharging module is connected to the switch module; The second end of the first switch is connected to one end of the boost module, and the third end of the first switch is connected to the controller; The other end of the boost module is connected to the voltage stabilizing module; The controller is connected to the switch module, and is used to output a control signal to the switch module and the first switch to control the switching of the switch module and the first switch, so that the boost converter outputs a boosted output voltage; The switch module includes: a second switch, a third switch and a fourth switch; The first end of the second switch is used to access the input voltage, the second end of the second switch is respectively connected to the first end of the first switch and one end of the charging and discharging module, and the third end of the second switch is connected to the controller; The first end of the third switch is used to access the input voltage, the second end of the third switch is respectively connected to the first end of the fourth switch and the other end of the charge and discharge module, and the third end of the third switch is connected to the controller; The first end of the fourth switch is respectively connected to the second end of the third switch and the other end of the charge and discharge module, the second end of the fourth switch is grounded, and the third end of the fourth switch is connected to the controller; The controller includes a clocked comparator, a dual clock oscillator, a feedback resistor network and a switch control module; The first switch, the second switch, the third switch and the fourth switch respectively include a plurality of switch tubes; The input end of the feedback resistor network is connected to the output end of the boost converter, and the feedback resistor network is used to convert the output voltage of the boost converter into a feedback voltage signal; The input end of the clock-controlled comparator is connected to the output end of the feedback resistor network, and the clock-controlled comparator is used to generate a clock selection signal according to the received feedback voltage signal and the reference voltage; The input end of the dual clock oscillator is connected to the output end of the clock control comparator, and the dual clock oscillator is used to determine whether to turn on the fast clock in the dual clock oscillator according to the clock selection signal, and when the fast clock is turned on, record the working cycle corresponding to the fast clock from the on time to the off time period; The switch control module is connected to the output end of the clock-controlled comparator and the output end of the dual-clock oscillator. The switch control module is used to output switch size control signals to the first switch, the second switch, the third switch and the fourth switch respectively according to the clock selection signal and the working cycle corresponding to the previous start of the fast clock, so as to control the opening and closing of each switch tube in the first switch, the second switch, the third switch and the fourth switch, so that the boost converter outputs the boosted output voltage.

2. The DC boost converter according to claim 1, characterized in that: The first switch is a three-terminal transistor.

3. The DC boost converter according to claim 1, characterized in that: The second switch, the third switch, and the fourth switch are three-terminal transistors respectively.

4. The DC boost converter according to claim 1, characterized in that: The charging and discharging module includes: a first capacitor.

5. The DC boost converter according to claim 1, characterized in that: The boost module includes: an inductor.

6. The DC boost converter according to claim 1, characterized in that: The voltage stabilizing module includes: a second capacitor.

7. The DC boost converter according to any one of claims 1 to 6, characterized in that: The DC boost converter also includes: a voltage detection module; The voltage detection module is connected to the first end, the second end of the first switch and the controller respectively.

8. The DC boost converter according to claim 7, characterized in that: The controller is used for detecting a voltage difference between a first end and a second end of the first switch through the voltage detection module, and outputting a control signal indicating disconnection to the first switch when the voltage difference reaches a first preset threshold.

9. The DC boost converter according to claim 1, characterized in that: The feedback resistor network includes: a fifth switch, a sixth switch, a seventh switch, a first resistor, a second resistor, and a third capacitor; One end of the fifth switch is connected to the output end of the boost converter, the other end of the fifth switch is connected to one end of the first resistor, a node where the other end of the first resistor and one end of the second resistor are connected is connected to one end of the sixth switch, the other end of the fifth switch is respectively connected to the input end of the clocked comparator and one end of the third capacitor, and the other end of the third capacitor is grounded; The other end of the second resistor is connected to one end of the seventh switch, and the other end of the seventh switch is grounded; The input end of the clock-controlled comparator is also connected to the output end of the dual-clock oscillator, and the clock-controlled comparator is also used to compare the feedback voltage signal and the reference voltage according to the working cycle of the fast clock or the clock frequency of the slow clock; The output end of the dual-clock oscillator is also connected to the fifth switch, the sixth switch and the seventh switch, and the dual-clock oscillator is also used to control the opening and closing of the fifth switch, the sixth switch and the seventh switch according to the working cycle of the fast clock or the working cycle of the slow clock.

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