Low-voltage adjustable current surge suppressor supporting rapid and continuous power-on

Abstract

The invention discloses a low-voltage adjustable current surge suppressor supporting rapid and continuous power-on, and belongs to the technical field of surge current suppression, the suppressor comprises a main power loop, a reference circuit, a control circuit and a voltage stabilizing circuit, the main power loop is composed of a sampling resistor and a power MOS tube which are connected in series, the reference circuit divides the auxiliary source voltage and then generates a reference source which can be used by the operational amplifier chip, the control circuit comprises the operational amplifier chip and a triode, and the voltage stabilizing circuit is used for protecting the MOS tube. Compared with the prior art, the suppressor combines the characteristics of an RC charging circuit, adopts an insulated gate field-effect tube to replace a resistor to penetrate into a main power loop, achieves the purpose of suppressing current by controlling the gate voltage of an MOS tube and controlling the conduction depth of the MOS tube, and can adjust the maximum surge current value by presetting the auxiliary source voltage at the same time. The surge protection circuit has the advantages of simple structure, quick and frequent starting, adjustable surge current, low power consumption, low failure rate and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of surge current suppression, and in particular relates to a low-voltage adjustable current surge suppressor supporting rapid and continuous power-on. Background Art

[0002] With the continuous development of electronic power technology, modern electronic equipment has a wider demand for power supply. Modern power supplies usually need to add capacitors at the input or output due to input filtering, power-off retention and other functional requirements. Capacitors will generate a large surge current at the moment of power-on. To suppress the surge current, an appropriate current surge suppression circuit should be added to the circuit.

[0003] Conventional surge current suppression circuits use resistors to limit current, specifically by using resistors to penetrate the main power circuit and charge the capacitors through the resistors to suppress the surge current at the moment of power-on. However, since the resistors penetrate the main power circuit, the system will have its own power consumption after normal operation, which will inevitably affect the system efficiency and is not suitable for scenarios with excessive current. How to improve the existing surge current suppression circuits and use low-cost simple circuits to solve the above technical problems has long troubled technicians in this field. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a low-voltage adjustable current surge suppressor that supports fast and continuous power-on. In combination with the characteristics of the RC charging circuit, an insulated gate field effect transistor is used to replace the resistor to penetrate the main power circuit.

[0005] The present invention solves the above problems by the following technical means: A low-voltage adjustable current surge suppressor supporting fast and continuous power-on, characterized in that it comprises a main power circuit, a reference circuit, a control circuit and a voltage stabilizing circuit, wherein: the main power circuit is composed of a sampling resistor and a power MOS tube connected in series, the negative input end of the power supply is connected to the source of the power MOS tube through the sampling resistor, the drain of the power MOS tube is connected to the negative output end of the power supply, the gate of the power MOS tube is connected to one end of the first resistor through a second resistor, and the other end of the first resistor is connected to the positive input end and the positive output end of the power supply; the reference circuit generates a voltage after dividing the auxiliary source voltage The control circuit comprises an operational amplifier chip and a triode, the positive input electrode of the operational amplifier chip is connected to the reference source generated by the reference circuit, the negative input electrode of the operational amplifier chip is connected to the sampling resistor, the output end of the operational amplifier chip is connected to the base of the triode through an eleventh resistor, the collector of the triode is connected to the source of the power MOS tube, and the emitter of the triode is connected to one end of the first resistor through a third resistor; the voltage stabilizing circuit comprises a voltage stabilizing tube, the anode of the voltage stabilizing tube is connected to the gate of the power MOS tube through a second resistor, and the negative electrode of the voltage stabilizing tube is connected to the source of the power MOS tube.

[0006] Preferably, the reference circuit is composed of a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor, wherein: a parallel circuit composed of the seventh resistor and the eighth resistor and a parallel circuit composed of the ninth resistor and the tenth resistor are connected in series between one end of the sixth resistor and a reference ground, the other end of the sixth resistor is connected to an auxiliary source voltage, and a reference source is generated by dividing the voltage between the seventh resistor and the ninth resistor, and between the eighth resistor and the tenth resistor.

[0007] Preferably, a voltage reference is further included, wherein the anode of the voltage reference is connected to the reference ground, the cathode and the reference end of the voltage reference are both connected to one end of the sixth resistor, and the voltage reference is used to generate a stable reference voltage value.

[0008] Preferably, the voltage reference may adopt a TL431 type controllable precision voltage regulator.

[0009] Preferably, it also includes a second capacitor, a fourth resistor and a fifth capacitor, wherein: the second capacitor is connected in parallel at both ends of the voltage regulator tube, and the fourth resistor and the fifth capacitor are connected in series and connected in parallel between the drain of the power MOS tube and the second resistor.

[0010] Preferably, it also includes a third capacitor, a twelfth resistor and a fourth capacitor, wherein: the third capacitor is connected in parallel between the output end and the negative input terminal of the operational amplifier chip, and the twelfth resistor and the fourth capacitor are connected in series and then in parallel with the third capacitor.

[0011] The low-voltage adjustable current surge suppressor supporting fast and continuous power-on of the present invention has the following beneficial effects: The suppressor combines the characteristics of the RC charging circuit, uses an insulated gate field effect tube to replace the resistor to penetrate the main power circuit, controls the gate voltage of the MOS tube, controls the conduction depth of the MOS tube to achieve the purpose of suppressing the current, and can also adjust the maximum surge current value by presetting the auxiliary source voltage. It has the advantages of simple structure, fast and frequent startup, adjustable surge current, low power consumption, low failure rate, etc. Among them, the feedback circuit composed of sampling resistors, operational amplifier chips, triodes, MOS tubes and corresponding resistors and capacitors is specifically used to achieve precise control of fast and adjustable surge current. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is the overall circuit diagram of the present invention. DETAILED DESCRIPTION

[0014] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0015] The present invention will be described in detail below with reference to the accompanying drawings.

[0016] like Figure 1 As shown, the low-voltage adjustable current surge suppressor supporting fast and continuous power-on includes a main power circuit, a reference circuit, a control circuit and a voltage stabilizing circuit. In the figure, the main power circuit is composed of a sampling resistor R5 and a power MOS tube Q1 connected in series, the negative input terminal VIN- of the power supply is connected to the source of the power MOS tube Q1 through the sampling resistor R5, the drain of the power MOS tube Q1 is connected to the negative output terminal VOUT- of the power supply, the gate of the power MOS tube Q1 is connected to one end of the first resistor R1 through the second resistor R2, and the other end of the first resistor R1 is connected to the positive input terminal VIN+ of the power supply and the positive output terminal VOUT+ of the power supply.

[0017] It should be noted that the suppressor combines the characteristics of the RC charging circuit and uses an insulated gate field effect transistor to replace the resistor to penetrate the main power circuit. It controls the gate voltage of the MOS tube and the conduction depth of the MOS tube to achieve the purpose of suppressing the current. At the same time, the maximum surge current value can be adjusted by presetting the auxiliary source voltage.

[0018] In the figure, the reference circuit divides the auxiliary source voltage VCC to generate a reference source that can be used by the operational amplifier chip IC2.

[0019] Specifically, the reference circuit is composed of a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a voltage reference IC1. The anode of the voltage reference IC1 is connected to the reference ground, and the cathode and the reference end of the voltage reference IC1 are connected to the sixth resistor R6, thereby generating a stable reference voltage value. The parallel circuit composed of the seventh resistor R7 and the eighth resistor R8 and the parallel circuit composed of the ninth resistor R9 and the tenth resistor R10 are connected in series between the cathode and the reference end of the voltage reference IC1 and the reference ground. The other end of the sixth resistor R6 is connected to the auxiliary source voltage VCC, and the reference source is generated by dividing the voltage between the seventh resistor R7 and the ninth resistor R9, and between the eighth resistor R8 and the tenth resistor R10. It should be noted that the voltage reference IC1 can adopt a TL431 type controllable precision voltage source.

[0020] In the figure, the control circuit includes an operational amplifier chip IC2 and a transistor VT1, the positive input of the operational amplifier chip IC2 is connected to the reference source generated by the reference circuit, the negative input of the operational amplifier chip IC2 is connected to the sampling resistor R5, the output end of the operational amplifier chip IC2 is connected to the base of the transistor VT1 through the eleventh resistor R11, the collector of the transistor VT1 is connected to the source of the power MOS tube Q1, and the emitter of the transistor VT1 is connected to one end of the first resistor R1 through the third resistor R3.

[0021] In actual operation, after power is turned on, the MOS tube Q1 in the main circuit charges the gate through the resistor R1, the MOS tube Q1 gradually turns on, and the sampling resistor R5 converts the current value flowing through into a voltage signal. At this time, two states will appear: State 1: The voltage on the sampling resistor is higher than the auxiliary source voltage preset by the reference circuit, the voltage on the same-direction input of the op amp is lower than the voltage on the reverse input, and the op amp outputs a low level, which controls the transistor VT1 to turn on. The gate voltage of the MOS tube is pulled down through the transistor VT1.

[0022] State 2: The voltage on the sampling resistor is lower than the auxiliary source voltage preset by the reference circuit, the voltage on the same-direction input terminal of the op amp is higher than the voltage on the reverse input terminal, and the op amp outputs a high level, which will control the transistor VT1 to turn off, and the gate voltage of the MOS tube is charged through the resistor R1 until it reaches the voltage regulation value of the voltage regulator tube VD1.

[0023] The state of the system can be quickly switched between state 1 and state 2. When the current needs to be suppressed, the gate voltage can be continuously controlled within the linear region voltage of the MOS tube Q1 through the cooperation of resistors R1~R4, capacitors C2, C5, and transistor VT1. In the linear region of the MOS tube, the MOS tube can be equivalent to a controlled resistor. As the gate voltage decreases, the lower the conduction degree, the greater the equivalent resistance. According to the characteristics of the RC charging circuit, the larger the resistance, the smaller the surge current generated. Through the discharge of the transistor VT1, the gate voltage can be quickly lowered, so that the current can be suppressed quickly and continuously.

[0024] In the figure, the voltage stabilizing circuit includes a voltage stabilizing tube VD1, the anode of the voltage stabilizing tube VD1 is connected to the gate of the power MOS tube Q1 through the second resistor R2, and the cathode of the voltage stabilizing tube VD1 is connected to the source of the power MOS tube Q1. The voltage stabilizing tube VD1 can effectively protect the MOS tube.

[0025] In addition, it also includes a second capacitor C2, a fourth resistor R4 and a fifth capacitor C5, wherein: the second capacitor C2 is connected in parallel at both ends of the voltage regulator tube VD1, and the fourth resistor R4 and the fifth capacitor C5 are connected in series and then connected in parallel between the drain of the power MOS tube Q1 and the second resistor R2. It also includes a third capacitor C3, a twelfth resistor R12 and a fourth capacitor C4, wherein: the third capacitor C3 is connected in parallel between the output end and the negative input electrode of the operational amplifier chip IC2, and the twelfth resistor R12 and the fourth capacitor C4 are connected in series and then connected in parallel with the third capacitor C3.

[0026] The suppressor combines the characteristics of the RC charging circuit, uses an insulated gate field effect transistor to replace the resistor to penetrate the main power circuit, and controls the gate voltage of the MOS tube and the conduction depth of the MOS tube to achieve the purpose of suppressing the current. At the same time, the maximum surge current value can be adjusted by presetting the auxiliary source voltage. It has the advantages of simple structure, fast and frequent startup, adjustable surge current, low power consumption, and low failure rate. Among them, the feedback circuit composed of sampling resistors, operational amplifier chips, triodes, MOS tubes and corresponding resistors and capacitors is specifically used to achieve precise control of fast and adjustable surge current. It should be further explained that in actual applications, software current detection can be used to replace the operational amplifier as a comparison circuit.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low voltage adjustable current surge suppressor supporting fast and continuous power-on, characterized in that: It includes main power circuit, reference circuit, control circuit and voltage stabilizing circuit, among which: The main power circuit is composed of a sampling resistor (R5) and a power MOS tube (Q1) connected in series, the negative input terminal (VIN-) of the power supply is connected to the source of the power MOS tube (Q1) through the sampling resistor (R5), the drain of the power MOS tube (Q1) is connected to the negative output terminal (VOUT-) of the power supply, the gate of the power MOS tube (Q1) is connected to one end of the first resistor (R1) through the second resistor (R2), and the other end of the first resistor (R1) is connected to the positive input terminal (VIN+) of the power supply and the positive output terminal (VOUT+) of the power supply; The reference circuit divides the auxiliary source voltage (VCC) to generate a reference source that can be used by the operational amplifier chip (IC2); The control circuit comprises an operational amplifier chip (IC2) and a transistor (VT1), the positive input electrode of the operational amplifier chip (IC2) is connected to a reference source generated by a reference circuit, the negative input electrode of the operational amplifier chip (IC2) is connected to a sampling resistor (R5), the output end of the operational amplifier chip (IC2) is connected to the base of the transistor (VT1) through an eleventh resistor (R11), the collector of the transistor (VT1) is connected to the source of a power MOS tube (Q1), and the emitter of the transistor (VT1) is connected to one end of the first resistor (R1) through a third resistor (R3); The voltage stabilizing circuit comprises a voltage stabilizing tube (VD1), wherein the anode of the voltage stabilizing tube (VD1) is connected to the gate of the power MOS tube (Q1) via a second resistor (R2), and the cathode of the voltage stabilizing tube (VD1) is connected to the source of the power MOS tube (Q1).

2. The low-voltage adjustable current surge suppressor supporting fast and continuous power-on according to claim 1, characterized in that: The reference circuit is composed of a sixth resistor (R6), a seventh resistor (R7), an eighth resistor (R8), a ninth resistor (R9) and a tenth resistor (R10), wherein: a parallel circuit composed of the seventh resistor (R7) and the eighth resistor (R8) and a parallel circuit composed of the ninth resistor (R9) and the tenth resistor (R10) are connected in series between one end of the sixth resistor (R6) and a reference ground, the other end of the sixth resistor (R6) is connected to an auxiliary source voltage (VCC), and a reference source is generated by dividing the voltage between the seventh resistor (R7) and the ninth resistor (R9) and between the eighth resistor (R8) and the tenth resistor (R10).

3. The low-voltage adjustable current surge suppressor supporting fast and continuous power-on according to claim 2, characterized in that: It also includes a voltage reference (IC1), wherein the anode of the voltage reference (IC1) is connected to the reference ground, the cathode and the reference end of the voltage reference (IC1) are both connected to one end of a sixth resistor (R6), and the voltage reference (IC1) is used to generate a stable reference voltage value.

4. The low-voltage adjustable current surge suppressor supporting fast and continuous power-on according to claim 3, characterized in that: The voltage reference (IC1) adopts a TL431 controllable precision voltage regulator.

5. The low-voltage adjustable current surge suppressor supporting fast and continuous power-on according to claim 1, characterized in that: It also includes a second capacitor (C2), a fourth resistor (R4) and a fifth capacitor (C5), wherein the second capacitor (C2) is connected in parallel to both ends of the voltage regulator tube (VD1), and the fourth resistor (R4) and the fifth capacitor (C5) are connected in series and then connected in parallel between the drain of the power MOS tube (Q1) and the second resistor (R2).

6. The low-voltage adjustable current surge suppressor supporting fast and continuous power-on according to claim 1, characterized in that: It also includes a third capacitor (C3), a twelfth resistor (R12) and a fourth capacitor (C4), wherein: the third capacitor (C3) is connected in parallel between the output end and the negative input terminal of the operational amplifier chip (IC2), and the twelfth resistor (R12) and the fourth capacitor (C4) are connected in series and then connected in parallel with the third capacitor (C3).

Images