Protection circuit of low dropout regulator, chip, equipment and system

Abstract

The invention relates to the technical field of circuit protection, particularly provides a protection circuit of a low dropout linear regulator, a chip, equipment and a system, and aims to solve the problem that the low dropout linear regulator has a fault when the input voltage of the low dropout linear regulator is too high or transient negative voltage is generated. In order to achieve the purpose, the protection circuit of the low-dropout linear voltage regulator comprises the low-dropout linear voltage regulator and a protection circuit module, wherein the protection circuit module comprises an input capacitor connected with the input end and the grounding end of the low dropout linear regulator, and a negative voltage clamping diode connected with the output end and the grounding end of the low dropout linear regulator.

Description

Technical Field

[0001] The present application relates to the field of circuit protection technology, and in particular to a protection circuit, chip, device and system for a low voltage dropout linear regulator. Background Art

[0002] Among the components of electric vehicles, the electronic system is the most important one, which includes the battery system, electric drive system and electronic control system.

[0003] In the electric drive system of electric vehicles, a three-phase full-bridge circuit is often used as a motor control. The three-phase full-bridge circuit is composed of six SiC Mosfet tubes. The controller in the electronic system can independently adjust the six SiC Mosfet tubes to control the speed and direction of the motor.

[0004] In the prior art, since SiC Mosfet tubes have high voltage requirements for the driving power supply, a low voltage dropout linear regulator is often used as a driving power supply for a SiC Mosfet tube. The low voltage dropout linear regulator generally includes a voltage divider sampling circuit, a reference voltage, an error amplifier circuit, and a transistor adjustment circuit. It can convert unstable input voltage into a stable output voltage, and then supply the output voltage to the SiC Mosfet tube for use. When the subsequent driving circuit connected to the output end of the low voltage dropout linear regulator generates high voltage or transient negative voltage, or when a low voltage dropout linear regulator supplies power to two SiC Mosfet tubes at the same time, the SiC Mosfet tube will generate high voltage or transient negative voltage, which will cause the low voltage dropout linear regulator to malfunction.

[0005] Accordingly, the art needs a new protection circuit for a low voltage dropout linear regulator to solve the above problems. Summary of the invention

[0006] In order to overcome the above-mentioned defects, the present application is proposed to solve or at least partially solve the technical problem that a low voltage dropout linear regulator fails when a high voltage or a transient negative voltage is generated by a subsequent driving circuit of the low voltage dropout linear regulator.

[0007] In a first aspect, a protection circuit for a low voltage dropout linear regulator is provided, comprising:

[0008] A low voltage dropout linear regulator and a protection circuit module; wherein the protection circuit module comprises: an input capacitor connected to the input end and the ground end of the low voltage dropout linear regulator, and a negative voltage clamping diode connected to the output end and the ground end of the low voltage dropout linear regulator.

[0009] In one of the above technical solutions, the protection circuit module further includes:

[0010] A high-voltage blocking diode and an output capacitor connected to both ends of the negative voltage clamping diode; wherein the high-voltage blocking diode and the output capacitor are connected in series.

[0011] In one of the above technical solutions, the protection circuit module further includes:

[0012] A feedback circuit is connected to both ends of the negative voltage clamping diode and an output end of an error amplifier in the low voltage dropout linear regulator.

[0013] In one of the above technical solutions, the feedback circuit includes:

[0014] Sampling resistor.

[0015] In one of the above technical solutions, the protection circuit module further includes:

[0016] The feedback circuit is connected to both ends of the output capacitor and the output end of the error amplifier.

[0017] In one of the above technical solutions, the protection circuit module further includes:

[0018] A first circulating current suppression circuit is connected to one end of the feedback circuit and one end of the output capacitor; and a second circulating current suppression circuit is connected to the other end of the feedback circuit and the other end of the output capacitor.

[0019] In one of the above technical solutions, the protection circuit module further includes:

[0020] A first low-voltage dropout linear regulator and a protection circuit module corresponding to the first low-voltage dropout linear regulator, a second low-voltage dropout linear regulator and a protection circuit module corresponding to the second low-voltage dropout linear regulator, and a third low-voltage dropout linear regulator and a protection circuit module corresponding to the third low-voltage dropout linear regulator are connected in parallel;

[0021] Among them, the input end and the ground end of the first low-voltage difference linear regulator are connected in parallel with two capacitors connected in series, the input end and the ground end of the second low-voltage difference linear regulator are connected in parallel with the two capacitors connected in series, and the input end and the ground end of the third low-voltage difference linear regulator are connected in parallel with the two capacitors connected in series.

[0022] In a second aspect, a chip is provided, the chip comprising the protection circuit of the low voltage dropout linear regulator according to any one of the first aspects.

[0023] In a third aspect, an electronic device is provided, comprising the protection circuit of the low voltage dropout linear regulator according to any one of the first aspects.

[0024] In a fourth aspect, an electronic system is provided, comprising the protection circuit of the low voltage dropout linear regulator according to any one of the first aspects.

[0025] The present application provides a protection circuit, chip, device and system for a low voltage difference linear regulator. The protection circuit of the low voltage difference linear regulator is specifically: a low voltage difference linear regulator and a protection circuit module; wherein the protection circuit module includes: an input capacitor connected to the input end and the ground end of the low voltage difference linear regulator, and a negative voltage clamping diode connected to the output end and the ground end of the low voltage difference linear regulator, which can suppress negative voltage and thus protect the low voltage difference linear regulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The disclosure of the present application will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present application. Among them:

[0027] Figure 1 A schematic diagram of the circuit structure of a first embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application;

[0028] Figure 2 A circuit structure diagram of a second embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application;

[0029] Figure 3 A schematic diagram of the circuit structure of a third embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application;

[0030] Figure 4 A circuit structure diagram of a fourth embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application;

[0031] Figure 5 A schematic diagram of the circuit structure of a fifth embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application;

[0032] Figure 6 A circuit structure diagram of a sixth embodiment of a protection circuit for a low voltage dropout linear regulator provided in the present application.

[0034] Reference numerals:

[0035] 10: input capacitor; 20: low voltage dropout linear regulator; 30: negative voltage clamping diode; 40: high voltage blocking diode; 50: output capacitor; 60: feedback circuit; 70: circulating current suppression circuit; 80: post-stage driving circuit; 90: capacitor. DETAILED DESCRIPTION

[0036] Some embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0037] In the description of the present application, "module" and "processor" may include hardware, software or a combination of the two. A module may include hardware circuits, various suitable sensors, communication ports, memory, and may also include software parts, such as program code, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor or any other suitable processor. The processor has data and / or signal processing functions. The processor may be implemented in software, hardware or a combination of the two. Computer-readable storage media include any suitable medium that can store program code, such as a disk, a hard disk, an optical disk, a flash memory, a read-only memory, a random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B or A and B. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and / or B" and may include only A, only B or A and B. The singular terms "one" and "the" may also include plural forms.

[0038] See attached Figure 1 , Figure 1 This is a circuit structure diagram of a protection circuit embodiment 1 of a low voltage dropout linear regulator provided by the present application. Figure 1 As shown, a protection circuit of a low voltage drop linear regulator in an embodiment of the present application mainly includes:

[0039] The low voltage dropout linear regulator 20 and the protection circuit module for protecting the low voltage dropout linear regulator, the connection terminals of the low voltage dropout linear regulator 20 include an input terminal, an output terminal and a ground terminal.

[0040] In this embodiment, the protection circuit module includes an input capacitor 10 and a negative voltage clamping diode 30, the two ends of the input capacitor 10 are respectively connected to the input end and the ground end of the low voltage difference linear regulator 20, the positive electrode of the negative voltage clamping diode 30 is connected to the ground end of the low voltage difference linear regulator 20, the negative electrode of the negative voltage clamping diode 30 is connected to the output end of the low voltage difference linear regulator 20, and the post-stage driving circuit 80 is connected in parallel with the negative voltage clamping diode 30.

[0041] In this embodiment, the input power supply of the low voltage difference linear regulator 20 is a DC power supply. When the input power supply is an AC power supply, the AC power passes through the input capacitor 10, thereby preventing the AC power from passing through the low voltage difference linear regulator 20, thereby protecting the low voltage difference linear regulator.

[0042] In this embodiment, the positive electrode of the negative voltage clamping diode 30 is connected to the ground terminal of the low voltage difference linear regulator 20, and the negative electrode of the negative voltage clamping diode 30 is connected to the output terminal of the low voltage difference linear regulator 20. By utilizing the unidirectional conductivity of the diode, the transient negative voltage generated by the subsequent driving circuit 80 can be suppressed, thereby protecting the low voltage difference linear regulator.

[0043] See attached Figure 2 , Figure 2 This is a circuit structure diagram of a second embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application. Figure 2 As shown, a protection circuit of a low voltage drop linear regulator in an embodiment of the present application mainly includes:

[0044] In this embodiment, the protection circuit module includes an input capacitor 10, a negative voltage clamping diode 30, a high voltage blocking diode 40, an output capacitor 50, and a post-stage driving circuit 80. The two ends of the input capacitor 10 are respectively connected to the input end and the ground end of the low voltage difference linear regulator 20, the positive electrode of the negative voltage clamping diode 30 is connected to the ground end of the low voltage difference linear regulator 20, the negative electrode of the negative voltage clamping diode 30 is connected to the output end of the low voltage difference linear regulator 20, the high voltage blocking diode 40 and the output capacitor 50 are connected in series and then connected in parallel with the negative voltage clamping diode 30, and the post-stage driving circuit 80 is connected in parallel with the output capacitor 50.

[0045] In this embodiment, the high voltage blocking diode 40 is located at the output end of the low voltage drop linear regulator 20. Therefore, the voltage supplied by the low voltage drop linear regulator 20 to the subsequent driving circuit 80 is the output voltage of the low voltage drop linear regulator 20 minus the voltage drop of the high voltage blocking diode 40.

[0046] In this embodiment, when the subsequent drive circuit 80 connected to the output end of the low voltage difference linear regulator 20 has a large voltage, the high voltage generated by the subsequent drive circuit 80 can be blocked by the high voltage blocking diode 40 and the output capacitor 50, thereby protecting the low voltage difference linear regulator.

[0047] See attached Figure 3 , Figure 3 This is a schematic diagram of the circuit structure of a third embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application. Figure 3 As shown, a protection circuit of a low voltage drop linear regulator in an embodiment of the present application mainly includes:

[0048] In this embodiment, the protection circuit module includes an input capacitor 10, a negative voltage clamping diode 30, a feedback circuit 60 and a post-stage driving circuit 80. The two ends of the input capacitor 10 are connected to the input end and the ground end of the low voltage difference linear regulator 20, the positive electrode of the negative voltage clamping diode 30 is connected to the ground end of the low voltage difference linear regulator 20, the negative electrode of the negative voltage clamping diode 30 is connected to the output end of the low voltage difference linear regulator 20, the three terminals of the feedback circuit 60 are respectively connected to the two ends of the negative voltage clamping diode 30 and the output end of the error amplifier inside the low voltage difference linear regulator 20, and the post-stage driving circuit 80 is connected in parallel with the feedback circuit 60.

[0049] In this embodiment, the feedback circuit 60 is a sampling resistor.

[0050] In this embodiment, the output voltage of the low voltage dropout linear regulator is adjusted by a sampling resistor, thereby obtaining a stable and accurate output voltage on the basis of protecting the low voltage dropout linear regulator.

[0051] See attached Figure 4 , Figure 4 This is a circuit structure diagram of a fourth embodiment of a protection circuit for a low voltage dropout linear regulator provided by the present application. Figure 4 As shown, a protection circuit of a low voltage drop linear regulator in an embodiment of the present application mainly includes:

[0052] In this embodiment, the protection circuit module includes an input capacitor 10, a negative voltage clamping diode 30, a high voltage blocking diode 40, an output capacitor 50, a feedback circuit 60 and a post-stage driving circuit 80. The two ends of the input capacitor 10 are respectively connected to the input end and the ground end of the low voltage difference linear regulator 20, the positive electrode of the negative voltage clamping diode 30 is connected to the ground end of the low voltage difference linear regulator 20, the negative electrode of the negative voltage clamping diode 30 is connected to the output end of the low voltage difference linear regulator 20, the high voltage blocking diode 40 and the output capacitor 50 are connected in series and then connected in parallel with the negative voltage clamping diode 30, the three terminals of the feedback circuit 60 are respectively connected to the output end of the error amplifier inside the low voltage difference linear regulator 20, the negative electrode of the high voltage blocking diode 40 and the positive electrode of the negative voltage clamping diode 30, and the post-stage driving circuit 80 is connected in parallel with the output capacitor 50.

[0053] In this embodiment, the cathode of the high-voltage blocking diode 40 is connected to the feedback circuit 60 , and the voltage drop of the high-voltage blocking diode 40 can also be statistically processed to ensure that the low-voltage dropout linear regulator outputs an accurate voltage.

[0054] In this embodiment, capacitors 50 are connected in parallel at both ends of the feedback circuit 60 to prevent the alternating current generated by the subsequent driving circuit 80 from damaging the feedback circuit 60, thereby effectively protecting the feedback circuit 60 while ensuring effective protection of the low-voltage difference linear regulator, so that the low-voltage difference linear regulator can output a stable and accurate voltage.

[0055] See attached Figure 5 , Figure 5 The circuit structure diagram of the fifth embodiment of the protection circuit of a low voltage drop linear regulator provided by the present application is shown in FIG. Figure 5 As shown, a protection circuit of a low voltage drop linear regulator in an embodiment of the present application mainly includes:

[0056] In this embodiment, the protection circuit module includes an input capacitor 10 , a negative voltage clamping diode 30 , a high voltage blocking diode 40 , an output capacitor 50 , a feedback circuit 60 , two circulating current suppression circuits 70 and a subsequent driving circuit 80 .

[0057] In this embodiment, the two ends of the input capacitor 10 are respectively connected to the input end and the ground end of the low voltage difference linear regulator 20, the anode of the negative voltage clamping diode 30 is connected to the ground end of the low voltage difference linear regulator 20, the cathode of the negative voltage clamping diode 30 is connected to the output end of the low voltage difference linear regulator 20, the three terminals of the feedback circuit 60 are respectively connected to the output end of the error amplifier inside the low voltage difference linear regulator 20, the cathode of the high voltage blocking diode 40 and the anode of the negative voltage clamping diode 30, the two circulating current suppression circuits 70 and the output capacitor 50 are connected in series and then connected to the two terminals of the feedback circuit 60, and the post-stage driving circuit 80 and the output capacitor 50 are connected in parallel.

[0058] In this embodiment, the two circulating current suppression circuits 70 have the same composition.

[0059] In this embodiment, for example, the circulating current suppression circuit 70 may include an inductor.

[0060] In this embodiment, the circulating current suppression circuit 70 can suppress high-frequency disturbances and improve the stability of the protection circuit.

[0061] See attached Figure 6 , Figure 6 The circuit structure diagram of the sixth embodiment of the protection circuit of a low voltage drop linear regulator provided by the present application is shown in FIG. Figure 6 As shown, a protection circuit of a low voltage drop linear regulator in an embodiment of the present application mainly includes:

[0062] In this embodiment, the protection circuit module includes a first low voltage difference linear regulator 20 and a protection circuit module corresponding to the first low voltage difference linear regulator 20, a second low voltage difference linear regulator 20 and a protection circuit module corresponding to the second low voltage difference linear regulator 20, and a third low voltage difference linear regulator 20 and a protection circuit module corresponding to the third low voltage difference linear regulator 20, which are connected in parallel.

[0063] In this embodiment, the input end and the ground end of the first low-voltage difference linear regulator 20 are connected in parallel with two capacitors 90 connected in series, the input end and the ground end of the second low-voltage difference linear regulator 20 are connected in parallel with two capacitors 90 connected in series, and the input end and the ground end of the third low-voltage difference linear regulator 20 are connected in parallel with two capacitors 90 connected in series.

[0064] In this embodiment, the first low-voltage difference linear regulator 20 and its protection circuit serve as the driving power supply circuit of the U-phase lower bridge, the second low-voltage difference linear regulator 20 and its protection circuit serve as the driving power supply circuit of the V-phase lower bridge, and the third low-voltage difference linear regulator 20 and its protection circuit serve as the driving power supply circuit of the W-phase lower bridge. In addition, because the input ends of the first low-voltage difference linear regulator 20, the second low-voltage difference linear regulator 20, and the third low-voltage difference linear regulator 20 share an input power supply, and the output ends of the three are independent of each other, a voltage difference is formed between the three groups of circuits UVW, forming a circulating current, and the circulating current suppression circuit 70 can suppress the generated circulating current. Similarly, due to the switching of the SiC Mosfet tubes of other phases, the high-frequency current forms a voltage difference in the loop, so that the input end of the first low-voltage difference linear regulator 20 is subjected to positive or negative voltage, and the high-voltage blocking diode 40 can block the high voltage of the subsequent drive circuit 80, and the negative voltage clamping diode 30 can clamp the transient negative voltage of the subsequent drive circuit 80.

[0065] In this embodiment, the circulating current suppression circuit 70 is located between the low voltage dropout linear regulator 20 and the driving circuit 80, and can suppress high frequency disturbance caused by the switching of the three-phase bridge power device.

[0066] Correspondingly, this embodiment further provides a chip, including the protection circuit of the above-mentioned low voltage dropout linear regulator.

[0067] Correspondingly, this embodiment further provides an electronic device, including the protection circuit of the above-mentioned low voltage dropout linear regulator.

[0068] Correspondingly, this embodiment further provides an electronic system, including the protection circuit of the above-mentioned low voltage dropout linear regulator.

[0069] So far, the technical solution of the present application has been described in conjunction with an embodiment shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. A protection circuit for a low voltage dropout linear regulator, characterized in that: include: A low voltage dropout linear regulator and a protection circuit module; wherein the protection circuit module comprises: an input capacitor connected to the input end and the ground end of the low voltage dropout linear regulator, and a negative voltage clamping diode connected to the output end and the ground end of the low voltage dropout linear regulator.

2. The protection circuit of a low voltage dropout linear regulator according to claim 1, characterized in that: The protection circuit module further includes: A high-voltage blocking diode and an output capacitor connected to both ends of the negative voltage clamping diode; wherein the high-voltage blocking diode and the output capacitor are connected in series.

3. The protection circuit of a low voltage dropout linear regulator according to claim 1, characterized in that: The protection circuit module further includes: A feedback circuit is connected to both ends of the negative voltage clamping diode and an output end of an error amplifier in the low voltage dropout linear regulator.

4. The protection circuit of a low voltage dropout linear regulator according to claim 3, characterized in that: The feedback circuit comprises: Sampling resistor.

5. The protection circuit of a low voltage dropout linear regulator according to claim 2, characterized in that: The protection circuit module further includes: A feedback circuit is connected to both ends of the output capacitor and an output end of an error amplifier in the low dropout linear regulator.

6. The protection circuit of a low voltage dropout linear regulator according to claim 4, characterized in that: The protection circuit module further includes: A first circulating current suppression circuit is connected to one end of the feedback circuit and one end of the output capacitor; and a second circulating current suppression circuit is connected to the other end of the feedback circuit and the other end of the output capacitor.

7. The protection circuit of a low voltage dropout linear regulator according to claim 5, characterized in that: The protection circuit module further includes: A first low-voltage dropout linear regulator and a protection circuit module corresponding to the first low-voltage dropout linear regulator, a second low-voltage dropout linear regulator and a protection circuit module corresponding to the second low-voltage dropout linear regulator, and a third low-voltage dropout linear regulator and a protection circuit module corresponding to the third low-voltage dropout linear regulator are connected in parallel; Among them, the input end and the ground end of the first low-voltage difference linear regulator are connected in parallel with two capacitors connected in series, the input end and the ground end of the second low-voltage difference linear regulator are connected in parallel with the two capacitors connected in series, and the input end and the ground end of the third low-voltage difference linear regulator are connected in parallel with the two capacitors connected in series.

8. A chip, characterized in that: A protection circuit comprising a low voltage dropout linear regulator as claimed in any one of claims 1 to 7.

9. An electronic device, characterized in that: A protection circuit comprising a low voltage dropout linear regulator as claimed in any one of claims 1 to 7.

10. An electronic system, characterized in that: A protection circuit comprising a low voltage dropout linear regulator as claimed in any one of claims 1 to 7.

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