Power supply voltage clamping circuit and electronic device
By switching signals through the first and second clamping modules and the microcontroller unit connected in parallel, the problems of excessively high clamping voltage and slow speed in the vehicle power circuit are solved, achieving faster overvoltage clamping and higher safety.
Patent Information
- Application Number
- CN202520165065.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2035-01-23
AI Technical Summary
In existing vehicle power supply circuits, the clamping voltage is too high and the overvoltage clamping speed is too slow, resulting in a high risk of damage to electronic components in the system.
The system employs first and second clamping modules and a microcontroller unit connected in parallel. The microcontroller unit controls the opening and closing of the clamping modules based on the switching signal of the power supply voltage steady-state value. Combined with the switching module, this improves clamping speed and safety.
It achieves faster overvoltage clamping response, reduces the risk of damage to electronic components in the system, and improves the safety and reliability of the circuit.
Smart Images
Figure CN223978574U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle power supply circuits, and in particular to a power supply voltage clamping circuit. Background Technology
[0002] Vehicle power supplies or control boxes typically use clamping circuits on the interface side to clamp the system voltage below a certain high voltage, preventing excessively high voltage pulses from damaging components on the circuit board. Currently, most products primarily use a TVS (transient voltage suppressor) connected in the power interface circuit. For example, in a 12V system, according to the overvoltage test in ISO 16750-2, the system will experience a 26V overvoltage lasting for one minute. Therefore, a TVS with clamping voltage parameters exceeding 26V is used in the interface circuit.
[0003] However, if a load dump occurs in the vehicle power supply, the bus voltage may fluctuate significantly, and the power interface voltage may experience high transients. The 26V TVS will take a long time to reduce the voltage to the clamping voltage, which may easily lead to damage to downstream electronic devices or other voltage-sensitive electronic devices in the bus circuit. Therefore, it is urgent to design a new voltage clamping circuit. Utility Model Content
[0004] Embodiments of this application provide a power supply voltage clamping circuit and electronic device to solve the problems of excessively high clamping voltage and slow overvoltage clamping speed.
[0005] To address the aforementioned technical problems, embodiments of this application disclose the following technical solutions:
[0006] On one hand, a power supply voltage clamping circuit is provided, the basic technical solution of which includes at least: a first clamping module, a second clamping module, and a microcontroller unit; the first clamping module and the second clamping module are connected in parallel between a power supply port and a ground port; the microcontroller unit has a first port and a second port, wherein the first port is configured to receive the power supply voltage, and the second port is configured to output a first switching signal when the steady-state value of the power supply voltage is less than a first voltage value, and to output a second switching signal when the steady-state value of the power supply voltage exceeds the first voltage value; the first switching signal enables the second clamping module to open, and the second switching signal enables the second clamping module to close; wherein the clamping voltage of the second clamping module is lower than the clamping voltage of the first clamping module, and the first voltage value is less than the clamping voltage of the second clamping module.
[0007] Furthermore, it also includes a switching module, which has a first terminal, a second terminal and a third terminal, wherein the first terminal is coupled to the second port of the microcontroller unit, the second terminal is coupled to the second clamping module, and the third terminal is coupled to the ground port; the first switching signal enables the switching module 5 to output a logic high level to turn on the second clamping module, and the second switching signal enables the switching module 5 to output a logic low level to turn off the second clamping module.
[0008] In the above-mentioned basic power supply voltage clamping circuit, the first clamping module includes at least a first transient voltage suppressor, and the start-up voltage of the first transient voltage suppressor is greater than the first voltage value.
[0009] Furthermore, the first clamping module also includes a first resistor and a first capacitor; the first resistor and the first capacitor are connected in parallel between the power supply port and the ground port.
[0010] In the aforementioned basic power supply voltage clamping circuit, the second clamping module includes at least a second transient voltage suppressor and a first switch; the activation voltage of the second transient voltage suppressor is a first voltage value, coupled between the power supply port and the first switch; the first switch has a first terminal, a second terminal, and a controlled terminal, wherein the first terminal is coupled to the second transient voltage suppressor, the second terminal is coupled to the ground port, and the controlled terminal is controlled by the first switching signal to open the path between the first terminal and the second terminal, and is controlled by the second switching signal to close the path between the first terminal and the second terminal.
[0011] Furthermore, the second clamping module also includes a second resistor and a second capacitor; the second resistor and the second capacitor are connected in parallel between the controlled terminal and the second terminal of the first switch.
[0012] In the aforementioned basic power supply voltage clamping circuit, the switching module includes at least a second switch and a third switch; the second switch has a first terminal, a second terminal, and a controlled terminal, wherein the first terminal receives the operating voltage, the second terminal is coupled to the second terminal of the switching module, and the controlled terminal is coupled to the third switch; the third switch has a first terminal, a second terminal, and a controlled terminal, wherein the first terminal is coupled to the controlled terminal of the second switch, the second terminal is coupled to the third terminal of the switching module, and the controlled terminal is coupled to the first terminal of the switching module; the operating voltage is greater than the on-state voltage of the second switch.
[0013] Furthermore, the operating voltage is provided by the built-in voltage source of the power supply voltage clamping circuit or by the power supply voltage; the switching module also includes a third resistor, a fourth resistor, and a fifth resistor; the third resistor is coupled between the second terminal of the second switch and the first terminal of the switching module; the fourth resistor is coupled between the first terminal of the second switch and the controlled terminal; the fifth resistor is coupled between the controlled terminal of the second switch and the first terminal of the third switch; when the controlled terminal of the third switch receives the first switching signal, the operating voltage is divided by the fourth and fifth resistors and provides a conduction voltage for the second switch.
[0014] Furthermore, the switching module also includes a sixth resistor and a seventh resistor; the sixth resistor is coupled between the first terminal of the switching module and the controlled terminal of the third switch; the seventh resistor is coupled between the controlled terminal of the third switch and the second terminal; the first switching signal is a logic high level, and the first switching signal enables the third switch to conduct after being divided by the sixth resistor and the seventh resistor.
[0015] On the other hand, an electronic device is provided, comprising at least a circuit board on which a power supply voltage clamping circuit as described in any of the above technical solutions is integrated.
[0016] The above-mentioned technical solutions have at least the following advantages or beneficial effects: the second clamping module is turned on when the power supply voltage is kept at a steady low voltage, and its clamping voltage is lower than that of the first clamping module. When a high voltage spike occurs in the power supply voltage, it absorbs the high voltage pulse before the first clamping module, providing the system with a lower clamping voltage, which can better protect the downstream electronic devices or voltage-sensitive devices in the system; at the same time, the microcontroller unit can turn off the second clamping module when the power supply voltage is at a steady high voltage, preventing damage to the second clamping module and further improving the safety of the power supply voltage clamping circuit itself.
[0017] In the above technical solution, the third switch in the switching module receives the controlled terminal signal through a voltage divider resistor. The device is simple, which can reduce the complexity and cost of the circuit control logic. At the same time, the switch in the switching module increases the driving capability of the second clamping module. Attached Figure Description
[0018] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.
[0019] Figure 1 This is a schematic diagram of a conventional transient voltage clamping circuit;
[0020] Figure 2 This is a block diagram of the power supply voltage clamping circuit of this application;
[0021] Figure 3 This is a block diagram of the clamping circuit module with switching module 5 in this application;
[0022] Figure 4 This is the circuit schematic diagram of the second clamping module 4 of this application;
[0023] Figure 5 This is the circuit schematic diagram of switching module 5 in this application;
[0024] Figure 6 A schematic diagram of an electronic device provided in this application. Detailed Implementation
[0025] To make the objectives, technical solutions, and beneficial effects of this application clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this application. It should be understood that the specific embodiments described in this specification are merely for explaining this application and are not intended to limit it.
[0026] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, 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, and therefore should not be construed as a limitation of this application. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.
[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "coupling" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0029] TVS (Transient Voltage Suppressor) is a semiconductor device specifically designed to protect circuits from transient voltage surges. It is commonly used to protect power lines and signal lines from overvoltage. Its principle is primarily based on the avalanche breakdown effect, which quickly limits transient high voltages to a safe range, protecting the safe operation of the circuit. Conventional transient voltage clamping circuits include... Figure 1 As shown, the circuit includes a first transient voltage suppressor transistor D1, a first resistor R1, and a first capacitor C1. The first transient voltage suppressor transistor D1 is a passive TVS. For example, in a 12V system, if D1 is a TPSMC30A, then under normal operating voltage, D1 presents high impedance and hardly affects the circuit operation. When the voltage rises instantaneously to above 30V, exceeding the breakdown voltage of D1, D1 quickly enters avalanche breakdown state, and its impedance drops sharply, thereby conducting the transient large current to the ground wire to avoid damage to subsequent circuits due to excessive voltage. After the transient impact, when the circuit voltage returns to the normal level, D1 automatically returns to the high impedance state. However, in the automotive environment, the power supply is provided by the vehicle battery, and the normal operating range of the battery fluctuates between 9-16V. Moreover, the circuits in automotive applications have higher safety requirements, and the clamping voltage of around 30V is still relatively high. Furthermore, the time for the overvoltage to decrease to the clamping voltage is relatively long, resulting in a high risk of damage to components in the circuit.
[0030] Figure 2This is a block diagram of the power supply voltage clamping circuit in this application. In this circuit, power port 1 receives the power supply voltage Vbat, ground port 2 is coupled to analog ground AGND, and the first clamping module 3 and the second clamping module 4 are both coupled between power port 1 and ground port 2. The microcontroller unit 6 has a first port and a second port, wherein the first port is used to receive the power supply voltage Vbat and measure the value of the power supply voltage Vbat through an internal sampling or monitoring unit, and the second port is used to output a first switching signal Ctrl1 and a second switching signal Ctrl2 to the second clamping module 4 to enable or disable the second clamping module 4, wherein the clamping voltage of the second clamping module 4 is less than the clamping voltage of the first clamping module 3; the microcontroller unit 6 is configured to output the first switching signal Ctrl1 when the steady-state value of the power supply voltage Vbat is less than a first voltage value, and to output the second switching signal when the steady-state value of the power supply voltage Vbat exceeds the first voltage value, wherein the first voltage value is less than the clamping voltage of the second clamping module 4.
[0031] Figure 3 This is a block diagram of the clamping circuit module with switching module 5 in this application, as shown below. Figure 3 As shown, the circuit is in Figure 2A switching module 5 is added to the clamping circuit shown. The switching module 5 receives a first switching signal Ctrl1 and a second switching signal Ctrl2 from the microcontroller unit 6, and outputs a logic level to the second clamping module 4. Specifically, the first clamping module 3 has a first terminal and a second terminal, wherein the first terminal is coupled to power port 1 and the second terminal is coupled to ground port 2; the second clamping module 4 has a first terminal, a second terminal, and a third terminal, wherein the first terminal is coupled to power port 1, the second terminal is coupled to ground port 2, and the third terminal is coupled to the switching module 5; the switching module 5 has a first terminal, a second terminal, and a third terminal, wherein the first terminal receives the switching signal, the second terminal is coupled to the third terminal of the second clamping module 4, and the third terminal is coupled to ground port 2; the microcontroller unit 6 has a first port and a second port ... port of the second clamping module 4, and the third terminal is coupled to ground port 2; the microcontroller unit 6 has a first port and a second port, wherein the first terminal One port is coupled to power port 1. The second port is configured to output a first switching signal Ctrl1 to the first terminal of the switching module 5 when the steady-state value of the power supply voltage Vbat is less than a first voltage value, and to output a second switching signal Ctrl2 to the first terminal of the switching module 5 when the steady-state value of the power supply voltage Vbat exceeds the first voltage value. The first switching signal enables the second terminal of the switching module 5 to output a logic high level LogicH, turning on the second clamping module 4. The second switching signal enables the second terminal of the switching module 5 to output a logic low level LogicL, turning off the second clamping module 4. When the second clamping module 4 is turned on, if the power supply voltage Vbat is greater than the start-up voltage of the second clamping module 4, the path between the first and second terminals of the first clamping module 3 is in a low-resistance state, ensuring that the voltage between power port 1 and ground port 2 does not exceed the clamping voltage of the first clamping module 3. If the power supply voltage Vbat is greater than the start-up voltage of the first clamping module 3, the path between the first and second terminals of the first clamping module 3 is in a low-resistance state, ensuring that the voltage between power port 1 and ground port 2 does not exceed the clamping voltage of the first clamping module 3. The clamping voltage of the first clamping module 3 is described; wherein the clamping voltage of the first clamping module 3 is greater than the clamping voltage of the second clamping module 4, and the clamping voltage of the second clamping module 4 is greater than the first voltage value; for example, in automotive applications, the power supply voltage fluctuation range is 9-16V, and in system testing, the power supply overvoltage is 18V, and the power supply overvoltage for jump start is 26V. Based on the above test conditions, the first voltage value is set to 18V, the first clamping module 3 selects a device with a clamping voltage of less than 45V, and the second clamping module 4 selects a device with a clamping voltage of less than 26V.The circuit described above provides a lower clamping voltage to the system through the second clamping module 4, and actively clamps the system voltage to a lower clamping voltage through the microcontroller unit 6 and the switching module 5, thereby improving the clamping response speed of the system overvoltage and better protecting the downstream electronic devices or voltage-sensitive devices on the circuit board. At the same time, under higher overvoltage, the second clamping module 4 is actively shut down to protect the clamping circuit itself and improve the overall safety.
[0032] Figure 4 This is the circuit schematic of the second clamping module 4 of this application, combined with... Figure 3 The block diagram shown indicates that the second clamping module 4 includes at least a second transient voltage suppressor D2 and a first switch Q1. One end of the second transient voltage suppressor D2 is coupled to the first terminal of the second clamping module 4, and the other end is coupled to the first switch Q1. The first switch Q1 has a first terminal, a second terminal, and a controlled terminal. The first terminal is coupled to the second transient voltage suppressor D2, the second terminal is coupled to the second terminal of the second clamping module 4 (i.e., connected to analog ground AGND), and the controlled terminal serves as the third terminal of the second clamping module 4. The controlled terminal receives a logic high level to open the path between the first and second terminals and receives a logic low level to close the path between the first and second terminals. The activation voltage of the second transient voltage suppressor D2 is a second voltage value. Furthermore, a second resistor R2 and a second capacitor C2 are connected in parallel between the controlled terminal and the second terminal of the first switch Q1. Figure 4 As shown, in this embodiment, the first switch Q1 is a P-channel MOSFET, the logic high level is the voltage across the second resistor R2, and the second capacitor C2 filters and reduces noise on the gate control signal of the P-channel MOSFET, improving the stability of the logic control circuit. Furthermore, Figure 3 In the schematic diagram shown, the first clamping module 3 and Figure 1 The transient voltage clamping circuit shown is the same. In a 9-16V automotive power supply circuit, the first transient voltage suppressor D1 can be a TPSMC30A, or a device with a higher clamping voltage can be selected to provide design margin, considering the specific downstream electronic components in the actual circuit. The second transient voltage suppressor D2 can be a TPSMC22A.
[0033] Figure 5 This is the circuit schematic of the switching module 5 in this application, combined with... Figure 3 The block diagram shown indicates that the switching module 5 includes at least a second switch Q2 and a third switch Q3; as shown... Figure 5As shown, the second switch Q2 has a first terminal, a second terminal, and a controlled terminal, wherein the first terminal receives the operating voltage, the second terminal is coupled to the second terminal of the switching module 5, and the controlled terminal is coupled to the third switch Q3; the third switch Q3 has a first terminal, a second terminal, and a controlled terminal, wherein the first terminal is coupled to the controlled terminal of the second switch Q2, the second terminal is coupled to the third terminal of the switching module 5, i.e., connected to analog ground AGND, and the controlled terminal is coupled to the first terminal of the switching module 5; the operating voltage is greater than the turn-on voltage of the second switch Q2, and the operating voltage is provided by the built-in voltage source of the power supply voltage clamping circuit or by the power supply voltage. Figure 5 As shown, in this embodiment, the operating voltage is 5V or 12V, and a regulated power supply can be built into the circuit system to provide a stable operating voltage. The second switch Q2 is an N-channel MOSFET, with its controlled terminal being the gate, the first terminal being the source, and the second terminal being the drain. The third switch Q3 is an NPN transistor, with its controlled terminal being the base, the first terminal being the collector, and the second terminal being the emitter. It should be understood that the selection of switching devices in this embodiment is not intended to limit the scope of the claims. In this embodiment, the switching module 5 improves the driving capability of the switching signal through two switching transistors, reducing the requirements on the output signal of the microcontroller unit 6.
[0034] like Figure 5 As shown, in this embodiment, the switching module 5 further includes a third resistor R3, a fourth resistor R4, and a fifth resistor R5; the third resistor R3 is coupled between the second terminal of the second switch Q2 and the first terminal of the switching module 5; the fourth resistor R4 is coupled between the first terminal of the second switch Q2 and the controlled terminal; the fifth resistor R5 is coupled between the controlled terminal of the second switch Q2 and the first terminal of the third switch Q3; when the controlled terminal of the third switch Q3 receives the first switching signal, the operating voltage is divided by the fourth resistor R4 and the fifth resistor R5 and provides a conduction voltage for the second switch Q2; combined with Figure 4 It can be seen that when the second switch Q2 is turned on, the working voltage is divided by the third resistor R3 and the second resistor R2, which can provide the turn-on voltage for the first switch Q1.
[0035] Furthermore, the switching module 5 also includes a sixth resistor R6 and a seventh resistor R7; the sixth resistor R6 is coupled between the first terminal of the switching module 5 and the controlled terminal of the third switch Q3; the seventh resistor R7 is coupled between the controlled terminal of the third switch Q3 and the second terminal; the first switching signal Ctrl1 is a logic high level, and the first switching signal Ctrl1 enables the third switch Q3 to conduct after being divided by the sixth resistor R6 and the seventh resistor R7, such as... Figure 5As shown, in this embodiment, the voltage on the seventh resistor R7 provides a forward bias voltage for the third switch Q3 to conduct the collector and emitter. However, it should be understood that the sixth resistor R6 and the seventh resistor R7 in this embodiment are not intended to limit the scope of protection of the independent claim. Those skilled in the art can design different conduction voltage conditions based on the specific selection of the third switch Q3. Figure 5 The switching module 5 shown has a simple logic control circuit and low component cost.
[0036] Figure 6 A schematic diagram of an electronic device provided in this application. Figure 6 As shown, the electronic device has at least one circuit board on which a power supply voltage clamping circuit is integrated. In this embodiment, the first clamping module 3, the second clamping module 4 and the switching module 5 in the power supply voltage clamping circuit are the same as in the above embodiments, and the microcontroller unit 6 is an MCU.
[0037] The above steps are provided only to help understand the method, structure, and core ideas of this application. Those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.
Claims
1. A power supply voltage clamping circuit, characterized by, Comprising: a first clamping module, a second clamping module and a micro control unit; the first clamping module and the second clamping module are coupled in parallel between a power port and a ground port; the micro control unit has a first port and a second port, wherein the first port is configured to receive the power voltage, and the second port is configured to output a first switching signal when the steady state value of the power voltage is less than a first voltage value, and output a second switching signal when the steady state value of the power voltage exceeds the first voltage value; the first switching signal enables to turn on the second clamping module, and the second switching signal enables to turn off the second clamping module; wherein the clamping voltage of the second clamping module is lower than the clamping voltage of the first clamping module, and the first voltage value is less than the clamping voltage of the second clamping module.
2. The power supply voltage clamping circuit of claim 1, wherein, Further comprising: a switching module having a first end, a second end and a third end, wherein the first end is coupled to the second port of the micro control unit, the second end is coupled to the second clamping module, and the third end is coupled to the ground port; the first switching signal enables the switching module to output a logic high level to turn on the second clamping module, and the second switching signal enables the switching module to output a logic low level to turn off the second clamping module.
3. The power voltage clamping circuit of claim 1, wherein: the first clamping module comprises at least a first transient voltage suppression tube, and the trigger voltage of the first transient voltage suppression tube is greater than the first voltage value.
4. The power voltage clamping circuit of claim 3, wherein: the first clamping module further comprises a first resistor and a first capacitor; the first resistor and the first capacitor are coupled in parallel between the power port and the ground port.
5. The power voltage clamping circuit of claim 1, wherein: the second clamping module comprises at least a second transient voltage suppression tube and a first switch; the trigger voltage of the second transient voltage suppression tube is the first voltage value, and the second transient voltage suppression tube is coupled between the power port and the first switch; the first switch has a first end, a second end and a controlled end, wherein the first end is coupled to the second transient voltage suppression tube, the second end is coupled to the ground port, and the controlled end is controlled by the first switching signal to turn on the path between the first end and the second end, and is controlled by the second switching signal to turn off the path between the first end and the second end.
6. The power voltage clamping circuit of claim 5, wherein: the second clamping module further comprises a second resistor and a second capacitor; the second resistor and the second capacitor are coupled in parallel between the controlled end and the second end of the first switch.
7. The power voltage clamping circuit of claim 2, wherein: the switching module comprises at least a second switch and a third switch; the second switch has a first end, a second end and a controlled end, wherein the first end receives the operating voltage, the second end is coupled to the second end of the switching module, and the controlled end is coupled to the third switch; The third switch has a first end, a second end and a controlled end, wherein the first end is coupled to the controlled end of the second switch, the second end is coupled to the third end of the switching module, and the controlled end is coupled to the first end of the switching module; The working voltage is greater than the on-voltage of the second switch.
8. The power supply voltage clamping circuit of claim 7, wherein, The working voltage is provided by a built-in voltage source of the power supply voltage clamping circuit or by a power supply voltage; The switching module further comprises a third resistor, a fourth resistor and a fifth resistor; The third resistor is coupled between the second end of the second switch and the first end of the switching module; The fourth resistor is coupled between the first end and the controlled end of the second switch; The fifth resistor is coupled between the controlled end of the second switch and the first end of the third switch; When the controlled end of the third switch receives a first switching signal, the working voltage is divided by the fourth resistor and the fifth resistor and provides an on-voltage for the second switch.
9. The power supply voltage clamping circuit of claim 7, wherein, The switching module further comprises a sixth resistor and a seventh resistor; The sixth resistor is coupled between the first end of the switching module and the controlled end of the third switch; The seventh resistor is coupled between the controlled end and the second end of the third switch; The first switching signal is a logic high level, and the first switching signal is divided by the sixth resistor and the seventh resistor to enable the third switch to be on.
10. An electronic device, comprising: At least comprising a circuit board, The circuit board is integrated with the power supply voltage clamping circuit according to any one of claims 1-9.