Voltage stabilizing circuit and vehicle-mounted power supply device

Abstract

The utility model provides a voltage stabilizing circuit and a vehicle-mounted power supply device, and the voltage stabilizing circuit comprises a first switching tube and an auxiliary switching tube which are connected in parallel between the input end and the output end of the voltage stabilizing circuit; the clamping circuit is respectively coupled with the input end of the voltage stabilizing circuit and the control end of the auxiliary switch tube, receives the input voltage of the voltage stabilizing circuit and outputs a first voltage to the control end of the auxiliary switch tube, and the first voltage is smaller than or equal to the first clamping voltage; and the voltage detection circuit is used for outputting a first turn-off trigger signal under the condition that the output voltage of the voltage stabilizing circuit is greater than a preset first threshold value, and the first turn-off trigger signal is used for triggering to realize turn-off operation on the first switching tube. According to the scheme, chip damage caused by overhigh output voltage due to loop out-of-control caused by latch-up negative current and the like can be effectively resisted, and the power supply reliability of a post-stage circuit is ensured.

Description

Technical Field

[0001] This application relates to the field of electronic circuits, specifically to a voltage regulator circuit and an on-board power supply device. Background Technology

[0002] A surge refers to an overload voltage or current that is much larger than the steady-state voltage or current peak value, generated at the moment the power is turned on or when an abnormality occurs in the circuit. Due to its high energy and large overcurrent, surge voltage is very harmful to the circuit and can easily lead to circuit damage.

[0003] With the rapid development of China's new energy industry in recent years, the demand for chips that can match new energy power electronics and some industrial production is also rising continuously. A stable and reliable power supply voltage from the power battery is a crucial prerequisite for the normal operation of these chips, especially under harsh working environments. Furthermore, in actual use, the rapid switching on and off of other load systems requires multiple power control interfaces and the power system itself, all of which are susceptible to voltage surges or sudden current changes.

[0004] To protect chips and electronic devices from damage during surges, surge suppression circuits need to be added to the power supply system. Existing surge suppression technologies are based on clamping techniques and operational amplifier loop control. However, for simple clamping solutions, implementation is difficult when the power supply output voltage range is wide, or implementation via external circuits is costly. For operational amplifier loop control solutions, if the circuit has a latchup that draws negative current, the chip's substrate (Sub) will have a negative voltage. In low-power design scenarios, part of the current bias may be drained, leading to operational amplifier failure, loop malfunction, and circuit runaway. Furthermore, if the power supply input voltage is high, the output voltage exceeding the damage voltage can cause irreversible damage to subsequent circuits. Utility Model Content

[0005] To address the aforementioned technical problems, this application provides a voltage regulator circuit and an on-board power supply device, which aims to suppress excessively high output voltage caused by loop runaway and ensure reliable power supply to subsequent circuits.

[0006] According to a first aspect of this application, a voltage regulator circuit is provided, comprising:

[0007] The first switching transistor is coupled between the input and output terminals of the voltage regulator circuit;

[0008] An auxiliary switching transistor is connected in parallel with the first switching transistor between the input and output terminals of the voltage regulator circuit.

[0009] The clamping circuit is coupled to the input terminal of the voltage regulator circuit and the control terminal of the auxiliary switch, respectively. It receives the input voltage of the voltage regulator circuit and outputs a first voltage less than or equal to the first clamping voltage to the control terminal of the auxiliary switch.

[0010] A voltage detection circuit is coupled to the output terminal of the voltage regulator circuit and the control terminal of the first switching transistor, respectively. The voltage detection circuit is used to output a first shutdown trigger signal when the output voltage of the voltage regulator circuit is greater than a preset first threshold. The first shutdown trigger signal is used to trigger the shutdown operation of the first switching transistor.

[0011] Optionally, the first clamping voltage is less than the output voltage of the voltage regulator circuit during normal operation.

[0012] Optionally, the clamping circuit includes:

[0013] The first resistor is coupled between the input terminal of the voltage regulator circuit and the control terminal of the auxiliary switching transistor;

[0014] The first clamping protection circuit is coupled between the control terminal of the auxiliary switch and the reference ground.

[0015] Optionally, the voltage regulator circuit further includes: a control circuit coupled to the control terminal of the first switching transistor to provide a control signal to the first switching transistor; and the voltage detection circuit is also coupled to the control circuit to provide a feedback signal of the output voltage of the voltage regulator circuit to the control circuit.

[0016] Optionally, the voltage regulator circuit further includes:

[0017] The overcurrent protection circuit has a first terminal that receives the loop current of the voltage regulator circuit and outputs a second shutdown signal when the loop current exceeds the overcurrent protection threshold. The second shutdown signal is used to trigger the shutdown operation of the first switching transistor.

[0018] Optionally, the voltage regulator circuit further includes:

[0019] The voltage protection circuit has a first terminal coupled to the input terminal of the voltage regulator circuit and a second terminal coupled to the control terminal of the first switching transistor. When the input voltage of the voltage regulator circuit is greater than a preset surge threshold, the voltage protection circuit controls the first switching transistor to turn off.

[0020] Optionally, the first switching transistor is a P-type transistor; the voltage protection circuit further includes a third terminal, which is coupled to the voltage detection circuit in the voltage regulator circuit. When the output voltage of the voltage regulator circuit is greater than a preset first threshold, the voltage detection circuit outputs a first shutdown trigger signal to the voltage protection circuit.

[0021] Optionally, the first switching transistor is a P-type transistor; the voltage regulator circuit further includes:

[0022] The first switch has a first terminal coupled to the input terminal of the voltage regulator circuit and a second terminal coupled to the control terminal of the first switch transistor. The control terminal is coupled to the voltage detection circuit in the voltage regulator circuit. When the output voltage of the voltage regulator circuit is greater than a preset first threshold, the voltage detection circuit outputs a first turn-off trigger signal to the control terminal of the first switch to control the first switch to turn on.

[0023] Optionally, the first switching transistor is an N-type transistor; when the output voltage of the voltage regulator circuit is greater than a preset first threshold, the voltage detection circuit outputs a first turn-off trigger signal to the control terminal of the first switching transistor.

[0024] Optionally, the voltage regulator circuit further includes a second clamping protection circuit, which is coupled to the voltage detection circuit, the input terminal and the output terminal of the voltage regulator circuit, respectively, and is used to provide a second voltage to the output terminal of the voltage regulator circuit when the first shutdown trigger signal is received, so as to clamp the output voltage of the voltage regulator circuit to the target range.

[0025] According to a second aspect of this application, an on-board power supply device is provided, comprising: a voltage regulator circuit as disclosed in any embodiment of this application.

[0026] The beneficial effects of this application include at least the following:

[0027] The voltage regulator circuit and vehicle power supply device provided in this application embodiment add an auxiliary switching transistor coupled in parallel with the first switching transistor (main switching transistor), as well as a clamping circuit and a voltage detection circuit to the voltage regulator circuit. The voltage detection circuit can control the main switching transistor to turn off when the output voltage is too high due to loop malfunction. The clamping circuit can clamp according to the input voltage and provide a first voltage less than or equal to the first clamping voltage to the control terminal of the auxiliary switching transistor. Under the action of the first voltage, the auxiliary switching transistor can conduct when the main switching transistor is off, thereby providing freewheeling power to the output terminal of the voltage regulator circuit. Compared with the existing solution, the solution of this application can suppress the excessive output voltage caused by loop malfunction due to latch-up negative current, so that the chip will not be damaged due to excessive supply voltage. It can ensure that the chip and other loads can continue to work when the voltage is abnormal, and ensure that the control system will not reset, thus enhancing the robustness of the system.

[0028] In a further preferred embodiment, a voltage protection circuit is also provided. When the input voltage of the voltage regulator circuit is greater than a preset surge threshold, the main switch is turned off. At this time, in conjunction with the auxiliary switch and clamping circuit, the output of the voltage regulator circuit can also be provided with freewheeling power during input voltage surges. This suppresses excessively high input voltages, ensuring that the chip and other loads can continue to work when the voltage is abnormal. This ensures that the control system will not reset, thus enhancing the robustness of the system.

[0029] It should be noted that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit this application. Attached Figure Description

[0030] Figure 1 This diagram shows a structural block diagram of a voltage regulator circuit provided according to an embodiment of this application;

[0031] Figure 2 Show Figure 1 A schematic diagram of the first embodiment of the main switch circuit;

[0032] Figure 3 Show Figure 1 A schematic diagram of a second embodiment of the main switch circuit;

[0033] Figure 4 Show Figure 1 A schematic diagram of an embodiment of the auxiliary switch circuit and clamping circuit;

[0034] Figure 5 Show Figure 4 A schematic diagram of one embodiment of the first clamping protection circuit in the middle;

[0035] Figure 6 Show Figure 1 A schematic diagram of a third embodiment of the main switch circuit;

[0036] Figure 7 Show Figure 1 A schematic diagram of the fourth embodiment of the main switch circuit;

[0037] Figure 8 Show Figure 1 A schematic diagram of the fifth embodiment of the main switch circuit. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application may be implemented in various forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0039] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0040] In the description of this application, words such as "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments. "And / or" in this document describes a relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. "Coupling" describes a connection relationship between related objects. For example, A and B are coupled, which can indicate a direct connection between A and B, or an indirect connection between A and B through other devices / units / modules. Furthermore, to facilitate a clear description of the technical solutions of the embodiments of this application, terms such as "first" and "second" are used to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or execution order, and that terms such as "first" and "second" do not necessarily imply differences.

[0041] Furthermore, the same reference numerals in the figures denote the same or similar structures, thus repeated descriptions of them will be omitted. That is, the various parts in this specification are described using a combination of parallel and progressive methods, with each part focusing on its differences from the others. Similar or identical parts can be referred to interchangeably. Terms expressing position and direction described in this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings in this application are for illustrating relative positional relationships only and do not represent actual scale.

[0042] refer to Figure 1 , Figure 1The diagram shows a structural block diagram of a voltage regulator circuit provided in an embodiment of this application. In this embodiment, the voltage regulator circuit 100 includes: a main switching circuit 110, a control circuit 120, an auxiliary switching circuit 130, a clamping circuit 140, and a voltage detection circuit 150. Optionally, the voltage regulator circuit 100 may be an LDO (Low Dropout Regulator) circuit.

[0043] In the embodiments of this application, the auxiliary switching circuit 130 and the main switching circuit 110 are connected in parallel, both coupled between the input and output terminals of the voltage regulator circuit 100. The first terminal of the control circuit 120 is coupled to the input terminal of the voltage regulator circuit 100, the second terminal of the control circuit 120 is coupled to the first output terminal of the voltage detection circuit 150, and the third terminal of the control circuit 120 is coupled to the control terminal of the main switching circuit 110. The first terminal of the clamping circuit 140 is coupled to the input terminal of the voltage regulator circuit 100, and the second terminal of the clamping circuit 140 is coupled to the control terminal of the auxiliary switching circuit 130. The first terminal of the voltage detection circuit 150 is coupled to the output terminal of the voltage regulator circuit 100, and the second output terminal of the voltage detection circuit 150 is coupled to the control terminal of the main switching circuit 110. In some embodiments, the third terminal of the clamping circuit 140 is coupled to the second terminal of the voltage detection circuit 150 to supply power to the voltage detection circuit 150.

[0044] The main switching circuit 110, under the combined action of the control circuit 120 and the voltage detection circuit 150, converts the high-voltage input voltage Vin into the target voltage, thereby obtaining the output voltage Vout. The main switching circuit 110 can achieve rapid response to both load changes and input voltage Vin changes.

[0045] In some specific embodiments, reference is made to Figure 2 , Figure 3 , Figure 6 , Figure 7 and Figure 8 The main switching circuit 110 includes a first switching transistor (also called the main switching transistor) M0 and a second switching transistor M1. The first switching transistor M0 is coupled between the input and output terminals of the voltage regulator circuit 100. The second switching transistor M1 and a current source circuit 10 are connected in series and coupled between the input terminal of the voltage regulator circuit 100 and a reference ground. Of course, in some other embodiments, the second switching transistor M1 may not be provided in the main switching circuit 110, or the second switching transistor M1 may adopt other common connection methods. Preferably, the first switching transistor M0 is a high-voltage resistant transistor so as to achieve compatibility with input and output voltages over a wide range.

[0046] Optionally, in applications requiring a wide voltage range for the input voltage Vin, a P-type transistor (including but not limited to a high-voltage P-type LDMOS transistor) can be used as the first switch M0; in applications requiring a relatively stable input voltage Vin, an N-type transistor (including but not limited to a high-voltage N-type LDMOS transistor) can be used as the first switch M0.

[0047] Further, refer to Figure 2 Figure 3 , Figure 6 and Figure 8 The main switching circuit 110 also includes an overcurrent protection circuit 230. The first terminal of the overcurrent protection circuit 230 receives the loop current from the voltage regulator circuit 100 and outputs a second shutdown signal when the loop current exceeds the overcurrent protection threshold. This second shutdown signal triggers the shutdown operation of the first switching transistor M0. It can be understood that by setting the overcurrent protection circuit 230, overcurrent protection and short-circuit protection functions can be achieved, preventing excessive output current from the voltage regulator circuit 100 from damaging the chip.

[0048] Optionally, when the first switching transistor M0 is a P-type transistor, the reference... Figure 2 , Figure 6 and Figure 7 At this time, the second terminal of the overcurrent protection circuit 230 is coupled to the input terminal of the voltage regulator circuit 100, and the third terminal of the overcurrent protection circuit 230 is coupled to the control terminal of the first switching transistor M0. When the first switching transistor M0 is an N-type transistor, refer to... Figure 3 and Figure 8 At this time, the second terminal of the overcurrent protection circuit 230 is coupled to the control terminal of the first switching transistor M0, and the third terminal of the overcurrent protection circuit 230 is coupled to the reference ground.

[0049] The control circuit 120 is used to provide corresponding control signals to the control terminals of the first switch M0 and the second switch M1 in the main switching circuit 110 based on the feedback signal VFB and the reference voltage Vref. The specific implementation circuit of the control circuit 120 can be understood by referring to existing solutions.

[0050] In some preferred embodiments, reference Figure 2 and Figure 3The voltage regulator circuit 100 further includes a floating voltage control circuit 220, which is coupled to both the input terminal of the voltage regulator circuit 100 and the control circuit 140, and is used to provide the control circuit 140 with a reference ground voltage that floats relative to the input voltage Vin of the voltage regulator circuit 100. In some embodiments, the control circuit 120 includes, for example, an error amplifier circuit, and the floating voltage control circuit 220 can at least provide the floating reference ground voltage to the negative power supply terminal of the error amplifier circuit in the control circuit 140. By using a floating ground to control the control circuit 140, the effects of input voltage fluctuations can be reduced or even avoided, which helps to improve the reliability of the control. The internal structure of the floating voltage control circuit 220 can be understood with reference to existing solutions.

[0051] The voltage detection circuit 150 receives the output voltage Vout and compares the output voltage Vout or a sampled signal of the output voltage Vout with a predetermined voltage threshold to detect the amplitude of the output voltage Vout and output a corresponding indication signal. In this embodiment, the voltage detection circuit 150 outputs a first turn-off trigger signal Voff at its second output terminal when the output voltage Vout of the voltage regulator circuit 100 is greater than a preset first threshold. The first turn-off trigger signal Voff is used to trigger the turn-off operation of the first switch M0 in the main switch circuit 110.

[0052] In some other embodiments, the voltage detection circuit 150 is also used to send the sampling result of the output voltage Vout to the control circuit 120. That is, the voltage detection circuit 150 is also used to provide the control circuit 120 with a feedback signal VFB of the output voltage Vout based on the output voltage Vout, so as to provide accurate output voltage feedback to the control circuit 120. Of course, the function of providing output voltage feedback to the control circuit 120 can also be provided by a separate circuit module.

[0053] Optionally, in some embodiments, when the first switching transistor M0 is a P-type transistor, such as Figure 6 and Figure 7 As shown, the voltage regulator circuit 100 also includes a voltage protection circuit 610. In Figure 6 In the illustrated embodiment, the first terminal of the voltage protection circuit 610 is coupled to the input terminal of the voltage regulator circuit 100, the second terminal of the voltage protection circuit 610 is coupled to the control terminal of the first switching transistor M0, and the third terminal of the voltage protection circuit 610 is coupled to the voltage detection circuit 150. In these embodiments, the first turn-off trigger signal Voff output by the voltage detection circuit 150 is transmitted to the voltage protection circuit 610, thereby the voltage protection circuit 610 sets the control terminal voltage of the first switching transistor M0 to an invalid state according to the first turn-off trigger signal Voff, so as to control the first switching transistor M0 to turn off. Figure 6In the illustrated embodiment, the voltage protection circuit 610 is simultaneously controlled by the input voltage Vin and the first turn-off trigger signal Voff, which is equivalent to multiplexing the voltage protection circuit 610 to achieve turn-off control of the first switching transistor M0. Figure 7 In the illustrated embodiment, the voltage protection circuit 610 controls the first switch M0 only based on the input voltage Vin. At this time, the first terminal of the protection circuit 610 is coupled to the input terminal of the voltage regulator circuit 100, and the second terminal of the voltage protection circuit 610 is coupled to the control terminal of the first switch M0. The voltage protection circuit 610 can set the control terminal voltage of the first switch M0 to an invalid state when the input voltage Vin is greater than a preset surge threshold, so as to control the first switch M0 to turn off. At the same time, the voltage regulator 100 also includes a switch S1 coupled between the input terminal of the voltage regulator circuit 100 and the control terminal of the first switch M0. The first turn-off trigger signal Voff output by the voltage detection circuit 150 is transmitted to the control terminal of the switch S1 to control the switch S1 to turn on, so that the control terminal voltage of the first switch M0 is set to an invalid state by the switch S1 in the on state, so as to control the first switch M0 to turn off. The voltage protection circuit 610, together with the auxiliary switching transistor and the clamping circuit 140, can provide freewheeling power to the output of the voltage regulator circuit 100 when the input voltage Vin surges, thereby suppressing excessively high input voltage Vin and ensuring that the chip and other loads can continue to work when the voltage is abnormal. This ensures that the control system will not reset and enhances the robustness of the system.

[0054] In other embodiments, when the first switching transistor M0 is an N-type transistor, such as Figure 8 As shown, the first turn-off trigger signal Voff output by the voltage detection circuit 150 can be directly transmitted to the control terminal of the first switching transistor M0, thereby setting the control terminal voltage of the first switching transistor M0 to an invalid state, thus controlling the first switching transistor M0 to turn off. Of course, other implementations are also possible. For example, a switching transistor can be set between the control terminal of the first switching transistor M0 and the reference ground, and the first turn-off trigger signal Voff output by the voltage detection circuit 150 can control the switching transistor to conduct in order to control the first switching transistor M0 to turn off. Alternatively, the voltage protection circuit 610 can be reused, etc.

[0055] In a further preferred embodiment, refer to Figure 6 , Figure 7 and Figure 8The voltage regulator circuit 100 further includes a second clamping protection circuit 620. This second clamping protection circuit 620 is coupled to the input and output terminals of the voltage detection circuit 150 and the voltage regulator circuit 100, respectively. Upon receiving a first shutdown trigger signal from the voltage detection circuit 150, it provides a second voltage to the output terminal of the voltage regulator circuit 100 to clamp the output voltage Vout of the voltage regulator circuit 100 to a target range. By setting the second clamping protection circuit 620, the voltage detection circuit 150 can quickly clamp the output voltage Vout within a safe area in the event of a failure of the chip's main switch control circuit, ensuring the reliability of the subsequent chips. The internal structure of the second clamping protection circuit 620 can be understood by referring to existing solutions.

[0056] refer to Figure 4 and Figure 5 In the embodiments of this application, the auxiliary switching circuit 130 is implemented as an auxiliary switching transistor M2, which is connected in parallel with the first switching transistor M0 between the input and output terminals of the voltage regulator circuit. Meanwhile, the clamping circuit 140 is coupled to both the input terminal of the voltage regulator circuit 100 and the control terminal of the auxiliary switching transistor M2, receiving the input voltage Vin from the voltage regulator circuit 100 and outputting a first voltage to the control terminal of the auxiliary switching transistor M2, wherein the first voltage is less than or equal to a first clamping voltage.

[0057] In a specific implementation, the clamping circuit 140 further includes: a resistor R1 and a first clamping protection circuit 410, wherein the resistor R1 is coupled between the input terminal of the voltage regulator circuit 100 and the control terminal of the auxiliary switch M2; and the first clamping protection circuit 410 is coupled between the control terminal of the auxiliary switch M2 and the reference ground.

[0058] The first clamping protection circuit 410 includes N transistors, which are connected in series between the control terminal of the auxiliary switch M2 and a reference ground. The control terminal of each transistor is also coupled to its drain. N is an integer greater than or equal to 1. Alternatively, in some other embodiments, the N transistors can be replaced with N Zener diodes, in which case the N Zener diodes are connected in series between the control terminal of the auxiliary switch M2 and the reference ground. N is an integer greater than or equal to 1. In this application, the first clamping voltage is positively correlated with the number N of the clamping transistors (such as transistors or Zener diodes) connected in series in the clamping circuit 140 and the clamping voltage of each clamping transistor. Furthermore, the first clamping voltage is less than the output voltage of the voltage regulator circuit during normal operation.

[0059] Figure 5An example of a first clamping protection circuit 410 including four transistors M51 to M54 is shown, but it is understood that the number N of transistors included in the first clamping protection circuit 410 can be arbitrary. Specifically, the value of N is positively correlated with the magnitude of the first voltage required to be provided by the clamping circuit 140.

[0060] In some embodiments, the auxiliary switch M2 is, for example, an N-channel field-effect transistor, and the first clamping voltage corresponding to the clamping circuit 140 is less than the output voltage Vout of the voltage regulator circuit 100 in steady state. Accordingly, the first voltage provided by the clamping circuit 140 to the control terminal of the auxiliary switch M2 is less than the output voltage Vout of the voltage regulator circuit 100 in steady state. Thus, the auxiliary switch M2 is in the off state during normal operation after the voltage regulator circuit 100 has started up.

[0061] During operation, during the initial power-on process of the voltage regulator circuit 100, the auxiliary switch M2 is turned on based on the first voltage provided by the clamping circuit 140, achieving a soft start. During normal operation after startup, if the first voltage received at the control terminal of the auxiliary switch M2 is less than the output voltage Vout, the auxiliary switch M2 is turned off. The voltage regulator circuit 100 then achieves stable energy output based on the main switch circuit 110 and the control circuit 120, for example, constant voltage and / or constant current energy output. In the event of a failure in the main circuit of the chip, such as an abnormality including but not limited to a surge in the output voltage Vout, the voltage detection circuit 150 quickly triggers the main switch M0 to turn off. Simultaneously, the auxiliary switch M2 remains on based on the first voltage provided by the clamping circuit 140, thus providing freewheeling power to the output terminal of the voltage regulator circuit 100. This ensures that the subsequent chip control system and other loads can continue to operate without resetting, until the system abnormality disappears and normal function is restored, thereby enhancing the robustness of the system.

[0062] Furthermore, embodiments of this application also provide an on-board power supply device, typically used in conventional or new energy vehicles, for storing and managing electrical energy. This on-board power supply device includes a voltage regulator circuit 100 as disclosed in any embodiment of this application. In the on-board power supply device, the voltage regulator circuit 100, for example, converts the battery voltage to obtain a stable power supply voltage for on-board chips and other loads.

[0063] The voltage regulator circuits and vehicle power supply devices disclosed in the embodiments of this application, by adding a voltage detection circuit and an auxiliary switching transistor to the voltage regulator circuit, can directly turn off the main switching transistor using the voltage detection circuit when the loop of the voltage regulator circuit fails to control, and continue to provide freewheeling power using the auxiliary switching transistor. This ensures that downstream chips will not be damaged due to excessive voltage, and also ensures that downstream vehicle chips and other system loads will not reset in emergency situations. In other words, the solution of this application can effectively resist chip damage caused by input voltage surges and loop failure due to latch-up negative current, thereby enhancing the robustness of the system.

[0064] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating this application and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A voltage regulator circuit, characterized in that, include: The first switching transistor is coupled between the input and output terminals of the voltage regulator circuit; An auxiliary switching transistor is connected in parallel with the first switching transistor between the input and output terminals of the voltage regulator circuit. The clamping circuit is coupled to the input terminal of the voltage regulator circuit and the control terminal of the auxiliary switch, respectively. It receives the input voltage of the voltage regulator circuit and outputs a first voltage less than or equal to the first clamping voltage to the control terminal of the auxiliary switch. A voltage detection circuit is coupled to the output terminal of the voltage regulator circuit and the control terminal of the first switching transistor, respectively. The voltage detection circuit is used to output a first shutdown trigger signal when the output voltage of the voltage regulator circuit is greater than a preset first threshold. The first shutdown trigger signal is used to trigger the shutdown operation of the first switching transistor.

2. The voltage regulator circuit according to claim 1, wherein, The first clamping voltage is less than the output voltage of the voltage regulator circuit during normal operation.

3. The voltage regulator circuit according to claim 1, wherein, The clamping circuit includes: The first resistor is coupled between the input terminal of the voltage regulator circuit and the control terminal of the auxiliary switching transistor; The first clamping protection circuit is coupled between the control terminal of the auxiliary switch and the reference ground.

4. The voltage regulator circuit according to claim 1, wherein, The voltage regulator circuit also includes: The control circuit is coupled to the control terminal of the first switching transistor and provides a control signal to the first switching transistor. The voltage detection circuit in the voltage regulator circuit is also coupled to the control circuit to provide the control circuit with a feedback signal of the output voltage of the voltage regulator circuit.

5. The voltage regulator circuit according to claim 1, wherein, The voltage regulator circuit also includes: The overcurrent protection circuit has a first terminal that receives the loop current of the voltage regulator circuit and outputs a second shutdown signal when the loop current exceeds the overcurrent protection threshold. The second shutdown signal is used to trigger the shutdown operation of the first switching transistor.

6. The voltage regulator circuit according to claim 1, wherein, Also includes: The voltage protection circuit has a first terminal coupled to the input terminal of the voltage regulator circuit and a second terminal coupled to the control terminal of the first switching transistor. When the input voltage of the voltage regulator circuit is greater than a preset surge threshold, the voltage protection circuit controls the first switching transistor to turn off.

7. The voltage regulator circuit according to claim 6, wherein, The first switching transistor is a P-type transistor; The voltage protection circuit also includes a third terminal, which is coupled to the voltage detection circuit. When the output voltage of the voltage regulator circuit is greater than a preset first threshold, the voltage detection circuit outputs a first shutdown trigger signal to the voltage protection circuit.

8. The voltage regulator circuit according to claim 1, wherein, The first switching transistor is a P-type transistor; the voltage regulator circuit further includes: The first switch has a first terminal coupled to the input terminal of the voltage regulator circuit and a second terminal coupled to the control terminal of the first switch transistor. The control terminal is coupled to the voltage detection circuit in the voltage regulator circuit. When the output voltage of the voltage regulator circuit is greater than a preset first threshold, the voltage detection circuit outputs a first turn-off trigger signal to the control terminal of the first switch to control the first switch to turn on.

9. The voltage regulator circuit according to claim 1, wherein, The first switching transistor is an N-type transistor; When the output voltage of the voltage regulator circuit is greater than a preset first threshold, the voltage detection circuit outputs a first shutdown trigger signal to the control terminal of the first switching transistor.

10. The voltage regulator circuit according to claim 1, wherein, The voltage regulator circuit also includes: The second clamping protection circuit is coupled to the input and output terminals of the voltage detection circuit and the voltage regulator circuit, respectively. It is used to provide a second voltage to the output terminal of the voltage regulator circuit when the first shutdown trigger signal is received, so as to clamp the output voltage of the voltage regulator circuit to the target range.

11. A vehicle-mounted power supply device, characterized in that, include: The voltage regulator circuit as described in any one of claims 1-10.

Images