Control integrated circuit and step-down power converter

Abstract

The application provides a control integrated circuit and a step-down power converter, wherein a semiconductor switch module is turned on according to a high-level driving signal and generates a first low level, or is turned off according to a low-level driving signal and generates a first high level; a transistor switch module is turned on according to the first low level and an auxiliary power module and generates a second high level, or is turned off according to the first high level and generates a second low level; a transistor driving module increases an output voltage according to the second high level and the auxiliary power module until a switch transistor is turned on, or decreases the output voltage according to the second low level until the switch transistor is turned off. The application comprises a semiconductor driving assembly composed of the semiconductor switch module, the transistor switch module and the transistor driving module, so that there is no low-impedance connection relationship between a control module and a direct-current input voltage, and the application can be directly applied to a high direct-current input voltage and a large-duty-cycle application scenario, and has the advantages of small size, low cost and wide application range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power supply, and particularly relates to a control integrated circuit and a step-down power converter. BACKGROUND

[0002] Generally, a control integrated circuit is arranged in a step-down power converter, which directly drives on and off of a switching transistor, but the withstand voltage of the control integrated circuit is generally low, and the withstand voltage of the existing control integrated circuit cannot meet the requirement when the input voltage is high.

[0003] In order to make the control integrated circuit be applied to the application scene with high input voltage, a driving transformer is generally used to control the on and off of the switching transistor, but this kind of mode cannot be applied to the scene with large duty cycle, and the excitation inductance of the driving transformer has a time delay effect on the driving signal and the transformer has a large volume. SUMMARY

[0004] The application aims to provide a control integrated circuit and a step-down power converter, and aims to solve the problem of low withstand voltage of the traditional control integrated circuit.

[0005] In order to achieve the above-mentioned purpose, in a first aspect, the application provides a control integrated circuit, comprising:

[0006] a semiconductor switch module configured to turn on according to a high-level driving signal and generate a first low level, or turn off according to a low-level driving signal and generate a first high level;

[0007] a triode switch module electrically connected with the semiconductor switch module and an auxiliary power module, configured to turn on according to the first low level and the auxiliary power module and generate a second high level, or turn off according to the first high level and generate a second low level;

[0008] a triode drive module electrically connected with the triode switch module and the auxiliary power module, configured to increase an output voltage according to the second high level and the auxiliary power module until a switching transistor turns on, or decrease the output voltage according to the second low level until the switching transistor turns off.

[0009] In a possible implementation manner of the first aspect, the semiconductor switch module comprises a first resistor and a second NPN triode;

[0010] One end of the first resistor is electrically connected with the driving signal, and the other end of the first resistor is electrically connected with the base of the second NPN triode;

[0011] Alternatively, the semiconductor switch module comprises a first resistor and a second NMOS tube;

[0012] One end of the first resistor is electrically connected with the driving signal, and the other end of the first resistor is electrically connected with the gate of the second NMOS tube.

[0013] In a further possible implementation form of the first aspect, the triode switch module comprises a second resistor and a third PNP triode;

[0014] One end of the second resistor is electrically connected with the collector of the second NPN triode or the drain of the second NMOS tube, and the other end of the second resistor is electrically connected with the base of the third PNP triode, and the emitter of the third PNP triode is electrically connected with the auxiliary power module.

[0015] In a further possible implementation form of the first aspect, the triode drive module comprises a third resistor, a fourth resistor, a fourth NPN triode, a fifth PNP triode and a fifth resistor;

[0016] One end of the third resistor is electrically connected with the collector of the third PNP triode, and the other end of the third resistor is electrically connected with the base of the fourth NPN triode, the base of the fifth PNP triode and one end of the fourth resistor, the collector of the fourth NPN triode is electrically connected with the auxiliary power module, the emitter of the fourth NPN triode and the emitter of the fifth PNP triode are electrically connected with one end of the fifth resistor, and the other end of the fourth resistor and the collector of the fifth PNP triode are grounded.

[0017] In a further possible implementation form of the first aspect, the semiconductor switch module further comprises a tenth resistor;

[0018] One end of the tenth resistor is electrically connected with the base of the second NPN triode, and the other end of the tenth resistor is electrically connected with the emitter of the second NPN triode.

[0019] Alternatively, one end of the tenth resistor is electrically connected with the gate of the second NMOS tube, and the other end of the tenth resistor is electrically connected with the source of the second NMOS tube.

[0020] In a further possible implementation form of the first aspect, the triode switch module further comprises a fifth capacitor, a second zener diode, a sixth resistor, a second diode, a third capacitor and a seventh resistor;

[0021] One end of the fifth capacitor, the positive electrode of the second voltage stabilizing diode and one end of the sixth resistor are electrically connected with one end of the second resistor, the other end of the fifth capacitor, the negative electrode of the second voltage stabilizing diode, the positive electrode of the second diode, one end of the third capacitor and one end of the seventh resistor are electrically connected with the base of the third PNP triode, the other end of the sixth resistor, the negative electrode of the second diode, the other end of the third capacitor and the other end of the seventh resistor are electrically connected with the emitter of the third PNP triode.

[0022] In a further possible implementation form of the first aspect, the triode driving module further comprises an eighth resistor, a ninth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a sixth NPN triode, a seventh PNP triode, a first voltage stabilizing diode and a fourth capacitor.

[0023] One end of the eighth resistor is electrically connected with the emitter of the fourth NPN triode and the emitter of the fifth PNP triode, the other end of the eighth resistor is electrically connected with the base of the sixth NPN triode, the base of the seventh PNP triode and one end of the ninth resistor, the collector of the fourth NPN triode is electrically connected with one end of the twelfth resistor, the collector of the sixth NPN triode is electrically connected with one end of the thirteenth resistor, the other end of the twelfth resistor and the other end of the thirteenth resistor are electrically connected with the auxiliary power module, the emitter of the sixth NPN triode, the emitter of the seventh PNP triode and the negative electrode of the first voltage stabilizing diode are electrically connected with one end of the fourth capacitor, the positive electrode of the first voltage stabilizing diode and the other end of the fourth capacitor are electrically connected with one end of the fifth resistor, the other end of the fifth resistor is electrically connected with one end of the eleventh resistor, the other end of the ninth resistor, the collector of the seventh PNP triode and the other end of the eleventh resistor are grounded.

[0024] In a further possible implementation form of the first aspect, the control integrated circuit further comprises a control module, a first capacitor, a first sampling resistor, a first NMOS tube, a first diode, a first inductor and a second capacitor.

[0025] The control module is electrically connected with the semiconductor switch module, one end of the first capacitor and one end of the first sampling resistor, the other end of the first capacitor and the drain of the first NMOS tube are electrically connected with the positive electrode of the input voltage terminal, the other end of the first sampling resistor is grounded, the gate of the first NMOS tube is electrically connected with the triode driving module, the source of the first NMOS tube is electrically connected with one end of the first inductor and the negative electrode of the first diode, the other end of the first inductor and one end of the second capacitor are electrically connected with the output voltage terminal, the positive electrode of the first diode and the other end of the second capacitor are grounded.

[0026] In a further possible implementation form of the first aspect, the control integrated circuit further comprises a control module, a first capacitor, a first sampling resistor, a first NMOS transistor, a ninth NMOS transistor, a first inductor and a second capacitor.

[0027] The control module is electrically connected with the semiconductor switch module, one end of the first capacitor and one end of the first sampling resistor, the other end of the first capacitor and the drain of the first NMOS transistor are electrically connected with a positive electrode of an input voltage terminal, the other end of the first sampling resistor is grounded, the gate of the first NMOS transistor is electrically connected with the triode drive module, the source of the first NMOS transistor is electrically connected with one end of the first inductor and the drain of the ninth NMOS transistor, the other end of the first inductor and one end of the second capacitor are electrically connected with an output voltage terminal, and the source of the ninth NMOS transistor and the other end of the second capacitor are grounded.

[0028] In a second aspect, an embodiment of the present application provides a step-down power converter comprising the control integrated circuit.

[0029] Compared with the prior art, the control integrated circuit has the beneficial effects that: the semiconductor switch module is turned on according to the high-level drive signal and generates a first low level, or is turned off according to the low-level drive signal and generates a first high level; the triode switch module is turned on according to the first low level and the auxiliary power supply module and generates a second high level, or is turned off according to the first high level and generates a second low level; the triode drive module increases the output voltage according to the second high level and the auxiliary power supply module until the switching transistor is turned on, or reduces the output voltage according to the second low level until the switching transistor is turned off. The semiconductor drive assembly composed of the semiconductor switch module, the triode switch module and the triode drive module makes the control module have no low-impedance connection relationship with the direct-current input voltage, and can be directly applied to high direct-current input voltage and high-duty-cycle application scenarios, has small size, low cost and wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort.

[0031] Figure 1 The first structure diagram of the conventional control integrated circuit provided by the embodiment of the present application is shown in the figure.

[0032] Figure 2A second structure diagram of a conventional control integrated circuit provided by the embodiment of the present application is shown in FIG. 2.

[0033] Figure 3 A driving voltage waveform diagram of the first structure of the conventional control integrated circuit provided by the embodiment of the present application is shown in FIG. 3.

[0034] Figure 4 A third structure diagram of a conventional control integrated circuit provided by the embodiment of the present application is shown in FIG. 4.

[0035] Figure 5 A driving voltage waveform diagram of the third structure of the conventional control integrated circuit provided by the embodiment of the present application is shown in FIG. 5.

[0036] Figure 6 A whole structure diagram of a control integrated circuit provided by the embodiment of the present application is shown in FIG. 6.

[0037] Figure 7 A first structure diagram of a control integrated circuit provided by the embodiment of the present application is shown in FIG. 7.

[0038] Figure 8 A second structure diagram of a control integrated circuit provided by the embodiment of the present application is shown in FIG. 8.

[0039] Figure 9 A first specific structure diagram of a control integrated circuit provided by the embodiment of the present application is shown in FIG. 9.

[0040] Figure 10 A second specific structure diagram of a control integrated circuit provided by the embodiment of the present application is shown in FIG. 10.

[0041] Figure 11 An output voltage waveform diagram of a control integrated circuit provided by the embodiment of the present application is shown in FIG. 11.

[0042] In the figures, the reference signs are as follows:

[0043] 1 - semiconductor switch module, 2 - triode switch module, 3 - triode drive module, 4 - auxiliary power supply module, 10 - control module. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects of the present application more clear, the present application will be further described in detail below in combination with the figures and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0045] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on the other component. When a component is referred to as being "electrically connected to" another component, it can be directly electrically connected to or indirectly electrically connected to the other component.

[0046] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0048] Currently, buck converters generally include a control integrated circuit that directly drives the switching transistors to turn on and off. However, the voltage withstand value of the control integrated circuit is generally low, and when the input voltage is high, the voltage withstand value of the existing control integrated circuit cannot meet the requirements.

[0049] Figure 1 This is a schematic diagram of a first structure of a conventional control integrated circuit provided in an embodiment of this application. Figure 2 This is a schematic diagram of a second structure of a conventional control integrated circuit provided in the embodiments of this application. For a conventional buck power converter with DC input and DC output, such as... Figure 1 As shown, it generally includes an input filter capacitor, a current sampling resistor, a high-voltage side switching transistor, a freewheeling diode, a filter inductor, an output filter capacitor, and a control circuit; or as shown in the diagram. Figure 2 As shown, it includes an input filter capacitor, a current sampling resistor, a high-voltage side switching transistor, a low-voltage side switching transistor, a filter inductor, an output filter capacitor, and a control circuit.

[0050] like Figure 1 As shown, the first transistor Q1 is typically a field-effect transistor, and the maximum voltage range that its gate and source can withstand is fixed (its absolute value is generally less than 30V, for example, ±30V). Based on the working principle of the buck converter, the drive voltage U(GS) applied between the gate and source of the first transistor Q1 will have the following states:

[0051] When U(G, S) is high voltage (for example: 10V), the first transistor Q1 is on; when U(G, S) is low voltage (for example: 0V), the first transistor Q1 is off. Therefore, the voltage value U(S, GND) between the source of the first transistor Q1 and the negative pole of the first auxiliary power supply (VCC1-GND) (or the negative pole of the input voltage VI-GND) has the following equation:

[0052] When the first transistor Q1 is on, U(S, GND) = U(VI, GND);

[0053] When the first transistor Q1 is off, U(S, GND) = -VD1 = -0.7V.

[0054] The voltage value U(S, GND) of the source of the first transistor Q1 is approximately the input voltage value VI during the on period of the first transistor Q1. During the off period of the first transistor Q1, due to the freewheeling effect of the first inductor L1, the voltage value is approximately the positive voltage drop VD1 (-0.7V) of the first diode D1.

[0055] It can be seen that the voltage value U(G, GND) between the gate of the first transistor Q1 and the negative pole of the first auxiliary power supply (VCC1-GND) (or the negative pole of the input voltage VI-GND) has the following equation:

[0056] When the first transistor Q1 is on, U(G, GND) = U(VI, GND) + U(G, S);

[0057] When the first transistor Q1 is off, U(G, GND) = -VD1 = -0.7V.

[0058] It can be seen that the voltage value U(G, GND) between the gate of the first transistor Q1 and the negative pole of the first auxiliary power supply (VCC1-GND) (or the negative pole of the input voltage VI-GND) has the following equation:

[0059] Because the driving signal output pin of the control module 10 is connected to the gate of the first transistor Q1 through a small driving resistor (generally less than 100Ω), the voltage value U(G, GND) of the gate is basically equal to the output voltage of the driving pin of the control module 10. Therefore, it can be seen that the output voltage of the driving pin of the control module 10 changes in the range of -0.7V to U(VI, GND) + U(G, S).

[0060] Figure 3 The output voltage waveform diagram of the first structure of the conventional control integrated circuit provided in the embodiment of the present application is as follows: Figure 3As shown, Ton is the turn-on time of the first transistor Q1 in one switching cycle, Toff is the turn-off time of the first transistor Q1 in one switching cycle, T is the switching cycle time of the first transistor Q1, U(G,S) is the voltage between the gate (G) and source (S) of the first transistor Q1, U(S,GND) is the voltage between the source (S) of the first transistor Q1 and the negative terminal of the first auxiliary power supply (VCC1-GND), and U(G,GND) is the voltage between the gate (G) of the first transistor Q1 and the negative terminal of the first auxiliary power supply (VCC1-GND). Because the maximum value of the voltage U(G,GND) at the drive pin of the control module 10 is U(VI,GND)+U(G,S), and the drive circuit of the control module 10 is a high-current, low-impedance circuit, the internal integrated circuit connected to the drive pin of the control module 10 must also be able to withstand a voltage with a maximum value of U(VI,GND)+U(G,S).

[0061] When the input voltage U(VI, GND) in buck converter applications is high (e.g., greater than 100V), existing commercially available control integrated circuits do not meet this voltage withstand requirement. Developing dedicated high-voltage control integrated circuits would be far more expensive than the market price range, making it economically unfeasible.

[0062] Figure 4 Figure 4 shows a third structural schematic diagram of a conventional control integrated circuit provided in the embodiments of this application. In the prior art, in order to apply the buck power converter to application scenarios with high input voltage, a driving method of controlling the conduction and turn-off of the switching transistor by driving the transformer is adopted. However, this method is not suitable for scenarios with a large duty cycle. At the same time, the magnetizing inductance of the driving transformer has a delay effect on the driving signal, and the transformer itself is large in size.

[0063] like Figure 4 As shown, T1 is the first drive transformer, D is the positive terminal of the drive output voltage of control module 10, and other circuit symbols are the same as those in the diagram. Figure 1 The same applies. The low-impedance drive output signal VD of the control module 10 is connected to the primary side of the first drive transformer T1 through the second transistor Q2 and the third transistor Q3, and its maximum withstand voltage value is the first auxiliary power supply voltage value U(VCC1,GND). The control module 10 is not connected to the input voltage VI by a low-impedance circuit, so the internal integrated circuit of the control module 10 does not need to withstand the input voltage U(VI,GND), but only the first auxiliary power supply voltage U(VCC1,GND).

[0064] Figure 5 The output voltage waveform diagram of the third structure of the conventional control integrated circuit provided in the embodiments of this application is as follows: Figure 5As shown, according to the working principle of the step-down power converter, the duty cycle D can be obtained as:

[0065] D = Ton / (Ton+Toff)

[0066] D = VO / VI

[0067] Since the first drive transformer T1 needs to meet the volt-second balance magnetic reset principle (U1*T1 = U2*T2), the absolute value of the positive gate voltage VG1 and the absolute value of the negative gate voltage VG2 of the first transistor Q1 need to meet:

[0068] VG1*Ton = VG2*Toff

[0069] Therefore, the duty cycle D of the drive signal voltage U(D, GND) of the control module 10 and the absolute value of the positive gate voltage VG1 and the absolute value of the negative gate voltage VG2 of the first transistor Q1 need to meet:

[0070] VG2 = D*VG1 / (1-D)

[0071] Therefore, when the duty cycle D is larger, the ratio of VG2 to VG1 is also larger, and when the duty cycle D = 80%, VG2 = 4*VG1. According to the general specification requirement, the positive gate drive voltage U(G, S) of the first field effect transistor Q1 is 10V, and VG2 = 4*VG1 = 40V. At this time, the absolute value of the negative gate voltage VG2 (40V) of the first transistor Q1 is greater than its maximum tolerable voltage value (generally less than 30V). Therefore, the method of using a drive transformer to control a switching transistor cannot be applied to a scenario with a large duty cycle. At the same time, since the excitation inductance of the drive transformer has a time delay effect on the drive signal, and the transformer itself has a large volume, it cannot be applied to a scenario with a high switching frequency, a small volume, and a high power density, and the application range is small, and the actual application value is low.

[0072] To solve the above problems, the application provides a control integrated circuit, which comprises a semiconductor switching module, a transistor switching module, and a transistor driving module to form a semiconductor driving assembly, so that there is no low-impedance connection relationship between the control module and the direct current input voltage, and the control integrated circuit can be directly applied to a high direct current input voltage and a scenario with a large duty cycle, and has a small volume, a low cost, and a wide application range.

[0073] Figure 6 The overall structure of the control integrated circuit provided by an embodiment of the application is shown in Figure 6 For ease of illustration, only parts related to the embodiment are shown, and the details are as follows: the control integrated circuit can include:

[0074] The semiconductor switch module 1 is configured to be turned on according to the high-level driving signal and generate a first low level, or be turned off according to the low-level driving signal and generate a first high level;

[0075] The triode switch module 2 is electrically connected with the semiconductor switch module 1 and the auxiliary power supply module 4, and is configured to be turned on according to the first low level and the auxiliary power supply module 4 and generate a second high level, or be turned off according to the first high level and generate a second low level;

[0076] The triode driving module 3 is electrically connected with the triode switch module 2 and the auxiliary power supply module 4, and is configured to increase the output voltage according to the second high level and the auxiliary power supply module 4 until the switch transistor is turned on, or decrease the output voltage according to the second low level until the switch transistor is turned off.

[0077] In the embodiment of the present application, the semiconductor switch module is turned on according to the high-level driving signal and generates a first low level, or is turned off according to the low-level driving signal and generates a first high level; the triode switch module is turned on according to the first low level and the auxiliary power supply module and generates a second high level, or is turned off according to the first high level and generates a second low level; the triode driving module increases the output voltage according to the second high level and the auxiliary power supply module until the switch transistor is turned on, or decreases the output voltage according to the second low level until the switch transistor is turned off, so that there is no low-impedance connection relationship between the control module and the direct-current input voltage, and no input high voltage needs to be borne by all circuits except the semiconductor switch Q2, and when applied to an application scenario with a large input voltage, the cost is lower and the reliability is higher. The auxiliary power supply module 4 includes an auxiliary power supply VCC2.

[0078] Figure 7 A first structure schematic diagram of the control integrated circuit provided by the embodiment of the present application, Figure 8 A second structure schematic diagram of the control integrated circuit provided by the embodiment of the present application, as shown in Figure 7 and Figure 8 Exemplarily, the semiconductor switch module 1 includes a first resistor R1 and a second NPN triode Q2;

[0079] One end of the first resistor R1 is electrically connected with the driving signal V1, and the other end of the first resistor R1 is electrically connected with the base of the second NPN triode Q2;

[0080] Alternatively, the semiconductor switch module 1 includes a first resistor R1 and a second NMOS tube Q2;

[0081] One end of the first resistor R1 is electrically connected with the driving signal V1, and the other end of the first resistor R1 is electrically connected with the gate of the second NMOS tube Q2.

[0082] In the embodiment of the present application, when the drive output signal U1(V1, VCC1-GND) of the control module 10 is high, current flows from the circuit network node V1 through the first resistor R1, the base of the second NPN transistor Q2(or the gate of the second NMOS transistor Q2), the emitter of the second NPN transistor Q2(or the source of the second NMOS transistor Q2) to the first auxiliary power supply negative pole VCC1-GND, at this time, the second NPN transistor Q2(or the second NMOS transistor Q2) is turned on, so that the voltage value of the circuit network node V2 approaches the voltage value of VCC1-GND(0V).

[0083] When the drive output signal U1(V1, VCC1-GND) of the control module 10 is low, no current flows into the base of the second NPN transistor Q2(or the gate of the second NMOS transistor Q2), at this time, the second NPN transistor Q2(or the second NMOS transistor Q2) is turned off.

[0084] As shown in Figure 7 and Figure 8 exemplarily, the transistor switch module 2 includes a second resistor R2 and a third PNP transistor Q3;

[0085] One end of the second resistor R2 is electrically connected with the collector of the second NPN transistor Q2 or the drain of the second NMOS transistor Q2, the other end of the second resistor R2 is electrically connected with the base of the third PNP transistor Q3, the emitter of the third PNP transistor Q3 is electrically connected with the auxiliary power supply module 4.

[0086] In the embodiment of the present application, when the voltage value of the circuit network node V2 decreases, current flows from the auxiliary power supply VCC2 through the emitter of the third PNP transistor Q3, the base of the third PNP transistor Q3 and the second resistor R2 to the circuit network node V2, at this time, the third PNP transistor Q3 is turned on, and the voltage of the circuit network node V3 approaches the voltage value of the auxiliary power supply positive pole VCC2.

[0087] When the second NPN transistor Q2(or the second NMOS transistor Q2) is turned off, no current flows through the second resistor R2 and the base of the third PNP transistor Q3, and no current flows through the emitter of the third PNP transistor Q3 and the collector of the third PNP transistor Q3, so the third PNP transistor Q3 is turned off.

[0088] As shown in Figure 7 and Figure 8 exemplarily, the transistor drive module 3 includes a third resistor R3, a fourth resistor R4, a fourth NPN transistor Q4, a fifth PNP transistor Q5 and a fifth resistor R5;

[0089] One end of the third resistor R3 is electrically connected with the collector of the third PNP transistor Q3, the other end of the third resistor R3 is electrically connected with the base of the fourth NPN transistor Q4, the base of the fifth PNP transistor Q5 and one end of the fourth resistor R4, the collector of the fourth NPN transistor Q4 is electrically connected with the auxiliary power module 4, the emitter of the fourth NPN transistor Q4 and the emitter of the fifth PNP transistor Q5 are electrically connected with one end of the fifth resistor R5, the other end of the fourth resistor R4 and the collector of the fifth PNP transistor Q5 are grounded.

[0090] In the embodiment of the present application, when the voltage of the circuit network node V3 approaches the voltage value of the positive electrode VCC2 of the auxiliary power supply, the current flows from the auxiliary power supply VCC2 through the third PNP transistor Q3 emitter, the third PNP transistor Q3 collector, the circuit network node V3, the third resistor R3, the fourth NPN transistor Q4 base, the fourth NPN transistor Q4 emitter, the fifth resistor R5, the first NMOS tube Q1 gate, the first NMOS tube Q1 source, and returns to the negative electrode VCC2-GND of the auxiliary power supply. When the current flows into the base of the fourth NPN transistor Q4, the collector of the fourth NPN transistor Q4 will have several times the base current flowing from the collector to the emitter of the fourth NPN transistor Q4 and the fifth resistor R5 to increase the driving capability and improve the charging speed of the parasitic capacitance between the gate and the source of the high-voltage side first NMOS tube Q1. At this time, the voltage U(G,S) between the gate and the source of the first NMOS tube Q1 gradually rises. When U(G,S) is greater than the turn-on threshold voltage of the first NMOS tube Q1, the first NMOS tube Q1 is turned on, at this time, the source voltage value of the first NMOS tube Q1 approaches the positive electrode VI value of the input direct current, the current flowing through the first inductor L1 gradually increases, and the direct current output voltage value U(VO,VO-GND) rises.

[0091] When the third PNP transistor Q3 is turned off, the circuit network node V3 is at a low level. The charge stored in the parasitic capacitance between the gate and source of the first NMOS transistor Q1 on the high-voltage side splits into two paths after passing through the gate of the first NMOS transistor Q1, the fifth resistor R5, and the emitter of the fifth PNP transistor Q5. Most of the current flows through the collector of the fifth PNP transistor Q5 to the negative terminal of the auxiliary power supply VCC2-GND, and a small portion of the current flows through the base of the fifth PNP transistor Q5 and the fourth resistor R4 to the negative terminal of the auxiliary power supply VCC2-GND. When the charge between the gate and source of the first NMOS transistor Q1 is released, the voltage U(G,S) between the gate and source of the first NMOS transistor Q1 gradually decreases. When the voltage U(G,S) is lower than the turn-on threshold voltage of the first NMOS transistor Q1, the first NMOS transistor Q1 is turned off, and the freewheeling current of the first inductor L1 turns on the first diode D1. At this time, the current flowing through the first inductor L1 gradually decreases, and the DC output voltage U(VO,VO-GND) decreases. The first-stage totem-pole drive circuit is composed of the fourth NPN transistor Q4 and the fifth PNP transistor Q5.

[0092] Figure 9 This is a schematic diagram of a first specific structure of the control integrated circuit provided in an embodiment of this application. Figure 10 This is a schematic diagram of a second specific structure of the control integrated circuit provided in an embodiment of this application. Figure 11 The output voltage waveform diagram of the control integrated circuit provided in the embodiments of this application is as follows: Figure 9 and Figure 10 As shown, by way of example, the semiconductor switch module 1 also includes a tenth resistor R10;

[0093] One end of the tenth resistor R10 is electrically connected to the base of the second NPN transistor Q2, and the other end of the tenth resistor R10 is electrically connected to the emitter of the second NPN transistor Q2.

[0094] Alternatively, one end of the tenth resistor R10 is electrically connected to the gate of the second NMOS transistor Q2, and the other end of the tenth resistor R10 is electrically connected to the source of the second NMOS transistor Q2.

[0095] In this embodiment, the tenth resistor R10 is used as a bias resistor to prevent input signal distortion.

[0096] like Figure 9 and Figure 10 As shown, by way of example, the transistor switching module 2 also includes a fifth capacitor C5, a second Zener diode ZD2, a sixth resistor R6, a second diode D2, a third capacitor C3, and a seventh resistor R7;

[0097] One end of the fifth capacitor C5, the positive electrode of the second zener diode ZD2 and one end of the sixth resistor R6 are electrically connected with one end of the second resistor R2, the other end of the fifth capacitor C5, the negative electrode of the second zener diode ZD2, the positive electrode of the second diode D2, one end of the third capacitor C3 and one end of the seventh resistor R7 are electrically connected with the base of the third PNP transistor Q3, the other end of the sixth resistor R6, the negative electrode of the second diode D2, the other end of the third capacitor C3 and the other end of the seventh resistor R7 are electrically connected with the emitter of the third PNP transistor Q3.

[0098] In the embodiment of the present application, the negative voltage generation circuit composed of the fifth capacitor C5, the second zener diode ZD2 and the sixth resistor R6 can make the third PNP transistor Q3 faster to turn off and improve the switching frequency; the second diode D2 is used to clamp the voltage value of the base and the emitter PN junction of the third PNP transistor Q3 when it is reversely biased, so that it is not broken down by reverse high voltage; the third capacitor C3 can avoid the third PNP transistor Q3 from being mistakenly turned on and improve the anti-interference capability; the seventh resistor R7 can avoid the second NPN transistor Q2 from being mistakenly turned on due to the increase of the base leakage current at high temperature, and increase the reliability.

[0099] As shown in Figure 9 and Figure 10 exemplarily, the triode driving module 3 further comprises an eighth resistor R8, a ninth resistor R9, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a sixth NPN transistor Q6, a seventh PNP transistor Q7, a first zener diode ZD1 and a fourth capacitor C4.

[0100] One end of the eighth resistor R8 is electrically connected with the emitter of the fourth NPN transistor Q4 and the emitter of the fifth PNP transistor Q5, the other end of the eighth resistor R8 is electrically connected with the base of the sixth NPN transistor Q6, the base of the seventh PNP transistor Q7 and one end of the ninth resistor R9, the collector of the fourth NPN transistor Q4 is electrically connected with one end of the twelfth resistor R12, the collector of the sixth NPN transistor Q6 is electrically connected with one end of the thirteenth resistor R13, the other end of the twelfth resistor R12 and the other end of the thirteenth resistor R13 are electrically connected with the auxiliary power supply module 4, the emitter of the sixth NPN transistor Q6, the emitter of the seventh PNP transistor Q7 and the negative electrode of the first zener diode ZD1 are electrically connected with one end of the fourth capacitor C4, the positive electrode of the first zener diode ZD1 and the other end of the fourth capacitor C4 are electrically connected with one end of the fifth resistor R5, the other end of the fifth resistor R5 is electrically connected with one end of the eleventh resistor R11, the other end of the ninth resistor R9, the collector of the seventh PNP transistor Q7 and the other end of the eleventh resistor R11 are grounded.

[0101] In the embodiment of the present application, the eighth resistor R8, the ninth resistor R9, the thirteenth resistor R13, the sixth NPN transistor Q6 and the seventh PNP transistor Q7 form the second stage totem pole drive current amplification circuit, which can further reduce the drive voltage rising time between the gate and the source of the first NMOS transistor Q1, so as to reduce the switching loss and improve the efficiency; the twelfth resistor R12 is used for limiting the current of the collector of the fourth NPN transistor Q4, and the resistor can adjust the drive voltage rising time between the gate and the source of the first NMOS transistor Q1; the first voltage stabilizing diode ZD1 and the fourth capacitor C4 form the negative drive voltage generation circuit, which can offset the disadvantage that the minimum value (1.4V) of the output voltage of the two-stage totem pole drive circuit cannot be reduced to 0V when the drive voltage between the gate and the source of the first NMOS transistor Q1 is reduced and cut off. The minimum point of the drive voltage waveform of the first NMOS transistor Q1 is slightly lower than 0V, so as to achieve the purpose of fast and reliable turn-off and anti-interference of the first NMOS transistor Q1.

[0102] Exemplarily, the control integrated circuit further comprises a control module 10, a first capacitor C1, a first sampling resistor RS1, a first NMOS transistor Q1, a first diode D1, a first inductor L1 and a second capacitor C2;

[0103] The control module 10 is electrically connected with the semiconductor switch module 1, one end of the first capacitor C1 and one end of the first sampling resistor RS1. The other end of the first capacitor C1 and the drain of the first NMOS transistor Q1 are electrically connected with the positive electrode of the input voltage end. The other end of the first sampling resistor RS1 is grounded. The gate of the first NMOS transistor Q1 is electrically connected with the triode drive module 3. The source of the first NMOS transistor Q1 is electrically connected with one end of the first inductor L1 and the negative electrode of the first diode D1. The other end of the first inductor L1 and one end of the second capacitor C2 are electrically connected with the output voltage end. The positive electrode of the first diode D1 and the other end of the second capacitor C2 are grounded.

[0104] In the embodiment of the present application, the control module 10 outputs a high-level drive signal or a low-level drive signal to control the whole circuit. The first capacitor C1 and the second capacitor C2 are used for filtering. The first sampling resistor RS1 is used for sampling the input current signal. The first NMOS transistor Q1 is used for generating a drive voltage. The first diode D1 is used for continuous current. The first inductor L1 is used for filtering.

[0105] Exemplarily, the control integrated circuit further comprises a control module 10, a first capacitor C1, a first sampling resistor RS1, a first NMOS transistor Q1, a ninth NMOS transistor Q9, a first inductor L1 and a second capacitor C2;

[0106] The control module 10 is electrically connected with the semiconductor switch module 1, one end of the first capacitor C1 and one end of the first sampling resistor RS1, the other end of the first capacitor C1 and the drain of the first NMOS Q1 are electrically connected with the positive electrode of the input voltage end, the other end of the first sampling resistor RS1 is grounded, the gate of the first NMOS Q1 is electrically connected with the triode driving module 3, the source of the first NMOS Q1 is electrically connected with one end of the first inductor and the drain of the ninth NMOS Q9, the other end of the first inductor L1 and one end of the second capacitor C2 are electrically connected with the output voltage end, and the source of the ninth NMOS Q9 and the other end of the second capacitor C2 are grounded.

[0107] In the embodiment of the present application, the whole circuit is controlled by the control module 10 outputting a high-level driving signal or a low-level driving signal, the input current signal is sampled by the first sampling resistor RS1, the driving voltage is generated by the first NMOS Q1, the freewheeling is realized by the ninth NMOS Q9, and the filtering is realized by the first inductor L1.

[0108] The application discloses a step-down power supply converter, which can exemplarily comprise a control integrated circuit.

[0109] In the embodiment of the present application, the semiconductor switch module, the triode switch module and the triode driving module constitute a semiconductor driving assembly, so that there is no low-impedance connection relationship between the control module and the direct-current input voltage, the semiconductor driving assembly can be directly applied to a high direct-current input voltage and an application scene with a large duty cycle, the overall circuit meets the industry technology development trend of miniaturization and power density improvement, has a wider application field than the prior art, has a lower cost, has good economic and social benefits, and therefore has a large application prospect.

[0110] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0111] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be realized in the form of hardware or software function unit. In addition, the specific name of each functional unit and module is only for the convenience of mutual distinction, and does not limit the protection scope of the present application. The specific working process of the unit and module in the above system can be referred to the corresponding process in the foregoing embodiments, which will not be described here.

[0112] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0113] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0114] In the embodiments provided in the present application, it should be understood that the disclosed control integrated circuit can be implemented by other means. For example, the above-described control integrated circuit embodiments are only illustrative, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division method, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0115] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment.

[0116] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0117] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A control integrated circuit, characterized in that, include: The semiconductor switch module is configured to turn on and generate a first low level according to a high-level drive signal, or turn off and generate a first high level according to a low-level drive signal; The transistor switching module is electrically connected to the semiconductor switching module and the auxiliary power module, and is configured to turn on the auxiliary power module according to the first low level and generate a second high level, or turn off the auxiliary power module according to the first high level and generate a second low level. The transistor driver module, electrically connected to the transistor switching module and the auxiliary power supply module, is configured to increase the output voltage until the switching transistor is turned on according to the second high level and the auxiliary power supply module; or decrease the output voltage until the switching transistor is turned off according to the second low level. The transistor switching module includes a second resistor, a third PNP transistor, a fifth capacitor, a second Zener diode, a sixth resistor, a second diode, a third capacitor, and a seventh resistor. One end of the second resistor is connected to the semiconductor switching module. One end of the fifth capacitor, the anode of the second Zener diode, and one end of the sixth resistor are electrically connected to the other end of the second resistor. The other end of the fifth capacitor, the cathode of the second Zener diode, the anode of the second diode, one end of the third capacitor, and one end of the seventh resistor are electrically connected to the base of the third PNP transistor. The other end of the sixth resistor, the cathode of the second diode, the other end of the third capacitor, the other end of the seventh resistor, and the auxiliary power supply module are all electrically connected to the emitter of the third PNP transistor. The transistor driving module includes a third resistor, a fourth resistor, a fourth NPN transistor, a fifth PNP transistor, an eighth resistor, a ninth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a sixth NPN transistor, a seventh PNP transistor, a first Zener diode, a fourth capacitor, and a fifth resistor. One end of the third resistor is electrically connected to the collector of the third PNP transistor, and the other end of the third resistor is electrically connected to the base of the fourth NPN transistor, the base of the fifth PNP transistor, and one end of the fourth resistor. The other end of the fourth resistor and the collector of the fifth PNP transistor are grounded. One end of the eighth resistor is electrically connected to the emitter of the fourth NPN transistor and the emitter of the fifth PNP transistor, and the other end of the eighth resistor is electrically connected to the base of the sixth NPN transistor. The base of the seventh PNP transistor and one end of the ninth resistor are electrically connected. The collector of the fourth NPN transistor is electrically connected to one end of the twelfth resistor. The collector of the sixth NPN transistor is electrically connected to one end of the thirteenth resistor. The other ends of the twelfth and thirteenth resistors are electrically connected to the auxiliary power supply module. The emitter of the sixth NPN transistor, the emitter of the seventh PNP transistor, and the cathode of the first Zener diode are electrically connected to one end of the fourth capacitor. The anode of the first Zener diode and the other end of the fourth capacitor are electrically connected to one end of the fifth resistor. The other end of the fifth resistor is electrically connected to one end of the eleventh resistor. The other end of the ninth resistor, the collector of the seventh PNP transistor, and the other end of the eleventh resistor are grounded.

2. The control integrated circuit as described in claim 1, characterized in that, The semiconductor switching module includes a first resistor and a second NPN transistor; One end of the first resistor is electrically connected to the drive signal, and the other end of the first resistor is electrically connected to the base of the second NPN transistor. Alternatively, the semiconductor switching module includes a first resistor and a second NMOS transistor; One end of the first resistor is electrically connected to the drive signal, and the other end of the first resistor is electrically connected to the gate of the second NMOS transistor.

3. The control integrated circuit as described in claim 2, characterized in that, The semiconductor switching module also includes a tenth resistor; One end of the tenth resistor is electrically connected to the base of the second NPN transistor, and the other end of the tenth resistor is electrically connected to the emitter of the second NPN transistor. Alternatively, one end of the tenth resistor is electrically connected to the gate of the second NMOS transistor, and the other end of the tenth resistor is electrically connected to the source of the second NMOS transistor.

4. The control integrated circuit according to any one of claims 1-3, characterized in that, The control integrated circuit also includes a control module, a first capacitor, a first sampling resistor, a first NMOS transistor, a first diode, a first inductor, and a second capacitor; The control module is electrically connected to the semiconductor switch module, one end of the first capacitor, and one end of the first sampling resistor. The other end of the first capacitor and the drain of the first NMOS transistor are electrically connected to the positive terminal of the input voltage terminal. The other end of the first sampling resistor is grounded. The gate of the first NMOS transistor is electrically connected to the transistor driving module. The source of the first NMOS transistor is electrically connected to one end of the first inductor and the negative terminal of the first diode. The other end of the first inductor and one end of the second capacitor are electrically connected to the output voltage terminal. The positive terminal of the first diode and the other end of the second capacitor are grounded.

5. The control integrated circuit according to any one of claims 1-3, characterized in that, The control integrated circuit also includes a control module, a first capacitor, a first sampling resistor, a first NMOS transistor, a ninth NMOS transistor, a first inductor, and a second capacitor; The control module is electrically connected to the semiconductor switch module, one end of the first capacitor, and one end of the first sampling resistor. The other end of the first capacitor and the drain of the first NMOS transistor are electrically connected to the positive terminal of the input voltage terminal. The other end of the first sampling resistor is grounded. The gate of the first NMOS transistor is electrically connected to the transistor driving module. The source of the first NMOS transistor is electrically connected to one end of the first inductor and the drain of the ninth NMOS transistor. The other end of the first inductor and one end of the second capacitor are electrically connected to the output voltage terminal. The source of the ninth NMOS transistor and the other end of the second capacitor are grounded.

6. A step-down power converter, characterized in that, Includes the control integrated circuit as described in any one of claims 1 to 5.

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