Intelligent clamping circuit and chip
By designing an intelligent clamp circuit, using the clamp detection module and the multi-stage bias voltage module to coordinate the control, the problem of inflexible passive response and protection methods of traditional voltage clamp circuits is solved, and high response speed, flexibility and reliability are achieved protection effect.
Patent Information
- Application Number
- CN202411526642.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-25
AI Technical Summary
Traditional voltage clamp circuits have problems such as passive response, inflexible protection methods, and poor reliability, and cannot be dynamically adjusted according to different working states of the load.
An intelligent clamping circuit is designed, including a clamp detection module, a first bias voltage providing module, a second bias voltage providing module and a freewheeling control module. Through the coordinated control of these modules, it can be based on the back electromotive force and load state. Dynamically adjust the working status and provide a multi-level protection mechanism.
It achieves higher response speed and flexibility, expands the protection range, improves the reliability of the protection effect, and reduces the overall power consumption of the circuit.
Smart Images
Figure CN119519678A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electronic circuits, and in particular to an intelligent clamping circuit and a chip. Background Art
[0002] In electronic circuits, when inductive loads such as motors and transformers are switched, they will try to maintain the continuity of the current due to the characteristics of the inductive element. That is, when the high-side switch turns off the inductive load, the current in the inductor cannot be stopped immediately, which will generate a reverse electromotive force. This reverse electromotive force will cause the output voltage to change sharply and may produce a voltage peak that exceeds the positive operating range. If the circuit is not properly protected, the sharply changing voltage will damage the semiconductor devices in the circuit. Therefore, a voltage clamp is needed to limit the voltage rise and protect the circuit from overvoltage damage.
[0003] Conventional voltage clamping circuits usually include passive components such as diodes and resistors, which are connected in parallel or series with the load to achieve voltage clamping, for example Figure 1 The figure shows a common clamping circuit, which limits the rise of the drain voltage of the power tube by connecting a diode in parallel between the drain of the power tube and the power supply. However, this type of traditional clamping circuit has certain limitations. Passive components can only respond passively, relying on the characteristics of the components to limit the voltage, and cannot be adjusted according to different working conditions of the load. The protection method is not flexible, the protection function is single, and it relies on a large number of diodes for protection. The circuit has high energy consumption, large losses to the diodes, and poor reliability. Summary of the invention
[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides an intelligent clamping circuit and chip, which solves the technical problems in the prior art that the traditional voltage clamping circuit can only achieve passive response and has poor flexibility and reliability in protection mode.
[0005] On one hand, the present invention provides an intelligent clamping circuit, including a clamping detection module, a first bias voltage providing module, a second bias voltage providing module and a freewheeling control module;
[0006] The power supply voltage is respectively connected to the first end of the clamp detection module, the first end of the second bias voltage providing module and the first end of the freewheeling control module;
[0007] The second end of the clamp detection module is connected to the first end of the first bias voltage providing module, and the third end of the clamp detection module is connected to the second end of the second bias voltage providing module;
[0008] The second end of the first bias voltage providing module is connected to the third end of the second bias voltage providing module, the third end of the second bias voltage providing module is also connected to the second end of the freewheeling control module, and the third end of the freewheeling control module is connected to the inductive load;
[0009] The clamp detection module is used to detect the back electromotive force of the inductive load. When the back electromotive force meets the clamp condition of the clamp detection module, the first bias voltage providing module provides a bias voltage to the second bias voltage providing module to activate the second bias voltage providing module to provide a bias voltage to the freewheeling control module, thereby enabling the freewheeling control module to generate a freewheeling path to release the energy of the inductive load.
[0010] Optionally, the clamp detection module includes a diode unit, a first resistor and a second resistor;
[0011] The first end of the diode unit is connected to the power supply voltage, the second end of the diode unit is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the first bias voltage providing module, and the second end of the first resistor is also connected to the second end of the second bias voltage providing module.
[0012] Optionally, the diode unit includes a first diode group and a second diode group;
[0013] The first diode group includes a first preset number of first diodes connected in series, and the second diode group includes a second preset number of second diodes connected in series;
[0014] In the first diode group, the anode of the first diode farthest from the second diode group is connected to the power supply voltage;
[0015] In the second diode group, an anode of a second diode farthest from the first diode group is connected to a first end of the first resistor;
[0016] At the connection between the first diode group and the second diode group, the cathode of the first diode in the first diode group is connected to the cathode of the second diode in the second diode group.
[0017] Optionally, the first preset number and the second preset number are determined based on a preset clamp of the clamp detection module.
[0018] Optionally, the first bias voltage providing module includes a power consumption circuit;
[0019] The drain of the power dissipation device is connected to the second end of the clamp detection module, the gate of the power dissipation device is connected to the source of the power dissipation device, and the source of the power dissipation device is connected to the third end of the second bias voltage providing module.
[0020] Optionally, the second bias voltage providing module includes a high voltage tube and a third resistor;
[0021] The drain of the high-voltage tube is connected to the power supply voltage, the gate of the high-voltage tube is connected to the third end of the clamp detection module, and the source of the high-voltage tube is connected to the second end of the freewheeling control module;
[0022] Two ends of the third resistor are respectively connected to the gate of the freewheeling control module and the source of the freewheeling control module.
[0023] Optionally, the freewheeling control module includes a power tube;
[0024] The drain of the power tube is connected to the power supply voltage, the gate of the power tube is respectively connected to the third end of the second bias voltage providing module, and the source of the power tube is connected to the inductive load.
[0025] Optionally, when the inductive load is powered off and the back electromotive force does not meet the clamping condition of the clamping detection module, the first bias voltage providing module controls the second bias voltage providing module to be in an off state so that the freewheeling control module is also in an off state.
[0026] Optionally, when the inductive load is in a normal working state, the first bias voltage providing module controls the second bias voltage providing module to be in a closed state, and the freewheeling control module is in a normal open and closed state.
[0027] Another aspect of the present invention provides a chip, comprising any one of the above-mentioned intelligent clamping circuits.
[0028] The intelligent clamping circuit and chip provided by the present invention can detect the back electromotive force generated by the inductive load by using the clamping detection module, and start when the clamping condition is met, with a higher response speed, and intervene in the early stage of the back electromotive force to prevent the voltage peak from being too high; the first bias voltage providing module and the second bias voltage providing module are set to realize a multi-level control mechanism, and the working state of each module can be dynamically adjusted according to the back electromotive force and different load conditions, with strong flexibility and a large protection range; when the clamping condition is met, the freewheeling control module provides a freewheeling path for the inductive load, allowing the current in the inductor to continue to flow, avoiding the high back electromotive force caused by the sudden interruption of the current, thereby protecting other components in the circuit from damage; the circuit as a whole adopts multiple functional modules for coordinated control, ensuring the reliability of the circuit function while reducing the power consumption of the circuit as a whole. Compared with the traditional clamping circuit, the above circuit has a higher response speed, flexible working mode, a larger protection range, and a reliable protection effect.
[0029] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.
[0030] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:
[0032] Figure 1 It is a circuit structure schematic diagram of a traditional voltage clamping circuit;
[0033] Figure 2 This is a schematic diagram of the overall structure of an intelligent clamping circuit in an embodiment provided in the present application;
[0034] Figure 3 A schematic diagram of the specific structure of a clamp detection module of an intelligent clamp circuit in an embodiment provided in the present application;
[0035] Figure 4 An actual circuit diagram of an intelligent clamping circuit in an embodiment provided in the present application;
[0036] Figure 5 A schematic diagram of the working principle of an intelligent clamping circuit in an embodiment provided in the present application.
[0037] In the figure:
[0038] NM1, power tube; NM2, high voltage tube; NM3, power tube;
[0039] D1, first diode; D2, second diode;
[0040] R1, first resistor; R2, second resistor; R3, third resistor;
[0041] Vx, first bias voltage; Vg, second bias voltage;
[0042] n1, a first preset number; n2, a second preset number. DETAILED DESCRIPTION
[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.
[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0046] On one hand, the present invention provides an intelligent clamping circuit, such as Figure 2As shown, it includes a clamp detection module, a first bias voltage providing module, a second bias voltage providing module and a freewheeling control module; wherein the power supply voltage is respectively connected to the first end of the clamp detection module, the first end of the second bias voltage providing module and the first end of the freewheeling control module; the second end of the clamp detection module is connected to the first end of the first bias voltage providing module, and the third end of the clamp detection module is connected to the second end of the second bias voltage providing module; the second end of the first bias voltage providing module is connected to the third end of the second bias voltage providing module, the third end of the second bias voltage providing module is also connected to the second end of the freewheeling control module, and the third end of the freewheeling control module is connected to the inductive load; the clamp detection module is used to detect the back electromotive force of the inductive load, and when the back electromotive force meets the clamping condition of the clamp detection module, the first bias voltage providing module provides a bias voltage to the second bias voltage providing module to activate the second bias voltage providing module to provide a bias voltage to the freewheeling control module, thereby enabling the freewheeling control module to generate a freewheeling path to release the energy of the inductive load.
[0047] The intelligent clamping circuit provided by the present invention can detect the back electromotive force generated by the inductive load by using the clamping detection module, and start when the clamping condition is met, with a higher response speed, and intervene in the early stage of the back electromotive force to prevent the voltage peak from being too high; the first bias voltage providing module and the second bias voltage providing module are set to realize a multi-level control mechanism, and the working state of each module can be dynamically adjusted according to the back electromotive force and different load conditions, with strong flexibility and a large protection range; when the clamping condition is met, the freewheeling control module provides a freewheeling path for the inductive load, allowing the current in the inductor to continue to flow, avoiding the high back electromotive force caused by the sudden interruption of the current, thereby protecting other components in the circuit from damage; the circuit as a whole adopts multiple functional modules for coordinated control, ensuring the reliability of the circuit function while reducing the power consumption of the circuit as a whole. Compared with the traditional clamping circuit, the above circuit has a higher response speed, flexible working mode, a larger protection range, and a reliable protection effect.
[0048] The present application provides a specific implementation of the intelligent clamping circuit, such as Figure 3 and Figure 4 As shown, the clamp detection module includes a diode unit, a first resistor R1 and a second resistor R2, the first end of the diode unit is connected to the power supply voltage, the second end of the diode unit is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the first end of the first bias voltage providing module, and the second end of the first resistor R1 is also connected to the second end of the second bias voltage providing module.
[0049] Furthermore, the first bias voltage providing module includes a drain of NM1, a drain of NM1 connected to the second end of the clamping detection module, a gate of NM1 connected to the source of NM1, and a source of NM1 connected to the third end of the second bias voltage providing module.
[0050] Furthermore, the second bias voltage providing module includes a high-voltage tube NM2 and a third resistor R3, the drain of the high-voltage tube NM2 is connected to the power supply voltage, the gate of the high-voltage tube NM2 is connected to the third end of the clamping detection module, the source of the high-voltage tube NM2 is connected to the second end of the freewheeling control module, and the two ends of the third resistor R3 are respectively connected to the gate of the freewheeling control module and the source of the freewheeling control module.
[0051] Furthermore, the freewheeling control module includes a power tube NM3, a drain of the power tube NM3 is connected to the power supply voltage, a gate of the power tube NM3 is respectively connected to the third end of the second bias voltage providing module, and a source of the power tube NM3 is connected to the inductive load.
[0052] like Figure 4 As shown, the present application provides a specific circuit structure diagram of an intelligent clamping circuit, wherein the first end of the diode unit is connected to the power supply voltage as the first end of the clamping detection module, the second end of the diode unit is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the drain of the power tube NM1 as the second end of the clamping detection module, the second end of the first resistor R1 is connected to the gate of the high-voltage tube NM2 as the third end of the clamping detection module, and the gate of the power tube NM1 is connected to the source, and at the same time, the source of the power tube NM1 is connected to the first end of the third resistor R3, the first end of the third resistor R3 is also connected to the source of the power tube NM3, the second end of the third resistor R3 is connected to the source of the high-voltage tube NM2, the drain of the high-voltage tube NM2 is connected to the power supply voltage, the source of the high-voltage tube NM2 is also connected to the gate of the power tube NM3, and the drain of the power tube NM3 is also connected to the power supply voltage, and the source of the power tube NM3 is connected to the inductive load.
[0053] Specifically, in the above embodiment, the diode unit includes a first diode group and a second diode group; the first diode group includes a first preset number n1 of first diodes D1 connected in series, and the second diode group includes a second preset number n2 of second diodes D2 connected in series; in the first diode group, the anode of the first diode D1 farthest from the second diode group is connected to the power supply voltage; in the second diode group, the anode of the second diode D2 farthest from the first diode group is connected to the first end of the first resistor R1; at the connection between the first diode group and the second diode group, the cathode of the first diode D1 in the first diode group is connected to the cathode of the second diode D2 in the second diode group.
[0054] The first preset number n1 and the second preset number n2 are determined based on a preset clamp of the clamp detection module.
[0055] Specifically, Figure 4 As shown, the diode unit is specifically divided into a first diode group and a second diode group, wherein the first diode group includes a first preset number n1 of first diodes D1 connected in series in sequence, and the second diode group includes a second preset number n2 of second diodes D2 connected in series in sequence, and the specific connection relationship is that in the first diode group, the anode of the first diode D1 at one end is connected to the power supply voltage, and the anode of this first diode D1 is connected to the anode of the next first diode D1, and multiple first diodes D1 are connected in sequence in the first diode group in this order, and the first diodes D1 in the first diode group are connected in sequence until the cathode of a first diode D1 is connected to the cathode of a second diode D2 at the connection between the first diode group and the second diode group, and in the second diode group, the anode of this second diode D2 is connected to the cathode of the next second diode D2, and multiple second diodes D2 are connected in sequence in the second diode group in this order until the anode of the last second diode D2 is connected to the first end of the first resistor R1.
[0056] In this embodiment, the specific number of the first diode D1 and the second diode D2 is determined by the clamping value required by the circuit, and the specific implementation form of the first diode D1 and the second diode D2 is not limited, and can be a MOS tube with gate and drain connection.
[0057] Specifically, in the above embodiment, when the inductive load is powered off and the back electromotive force does not meet the clamping condition of the clamping detection module, the first bias voltage providing module controls the second bias voltage providing module to be in a closed state, so that the freewheeling control module is also in a closed state; when the inductive load is in a normal working state, the first bias voltage providing module controls the second bias voltage providing module to be in a closed state, and the freewheeling control module is in a normal open and closed state.
[0058] Based on the specific structural diagram of the above-mentioned intelligent clamping circuit, the working principle of the intelligent clamping circuit of the present application is specifically explained. The circuit can be specifically divided into two working states, one of which is a state when clamping does not occur. In this state, it can be specifically divided into two situations. One situation is that the inductive load is under normal working conditions, and the power tube NM1 pulls down the high-voltage tube NM2, so that the power tube NM3 switches normally; and the other situation is that when the high-side switch of the inductive load is turned off, and the back electromotive force generated by the inductor does not reach the clamping value, the power tube NM1 still pulls down the high-voltage tube NM2, and the power tube NM3 remains in the off state.
[0059] The other is the state when the clamping mechanism is working, that is, when the back electromotive force generated by the inductor is high enough and meets the clamping condition, the diode unit, the first resistor R1 and the second resistor R2 in the clamping detection module are all in working state. At this time, the voltage divider network formed by the first resistor R1, the second resistor R2 and the power consumption NM1 provides a first bias voltage Vx to turn on the high-voltage tube NM2, and the current flows through the third resistor R3 to generate a voltage drop, thereby generating a second bias voltage Vg for the power tube NM3. After that, as the voltage across the third resistor R3 rises, when the second bias voltage Vg reaches the turn-on threshold of the power tube NM3, the power tube NM3 starts to conduct, thereby providing a freewheeling path so that the current in the inductor continues to flow, thereby achieving freewheeling and protecting the chip. Among them, the conduction of the power tube NM3 releases the energy in the inductor, avoiding overvoltage caused by intermittent inductance, such as Figure 5 As shown, the output voltage VOUT is always limited to the VS-VDS(CL) value, that is, the power supply voltage minus the drain-source voltage of the power tube NM3 in the on state.
[0060] The present application proposes an intelligent clamping circuit, which improves the clamping mechanism, utilizes the gate-drain voltage of the power tube NM3 to clamp the drain-source voltage, and utilizes the power tube NM3 for freewheeling, thereby effectively reducing the demand for diodes, thereby significantly improving the chip integration, alleviating the pressure on the diode, reducing the risk of breakdown, improving the clamping efficiency and stability, and enhancing the overall performance of the circuit, making it suitable for more stringent working environments; at the same time, the reduction of diodes also correspondingly reduces the generation of heat, simplifies the heat dissipation design, and is conducive to maintaining the circuit running at normal operating temperature.
[0061] On the other hand, the present invention provides a chip, including any one of the above-mentioned intelligent clamping circuits, and a multi-level protection mechanism is established by using the intelligent clamping circuit, so that the chip has the functions of active detection and rapid response, and can realize dynamic adjustment, and has a wide applicability. The integrated intelligent clamping circuit chip is particularly suitable for application scenarios that need to process inductive loads and have strict requirements for overvoltage protection, and can significantly improve the overall performance and reliability of the system.
[0062] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. An intelligent clamping circuit, characterized in that: It includes a clamping detection module, a first bias voltage providing module, a second bias voltage providing module and a freewheeling control module; The power supply voltage is respectively connected to the first end of the clamp detection module, the first end of the second bias voltage providing module and the first end of the freewheeling control module; The second end of the clamp detection module is connected to the first end of the first bias voltage providing module, and the third end of the clamp detection module is connected to the second end of the second bias voltage providing module; The second end of the first bias voltage providing module is connected to the third end of the second bias voltage providing module, the third end of the second bias voltage providing module is also connected to the second end of the freewheeling control module, and the third end of the freewheeling control module is connected to the inductive load; The clamp detection module is used to detect the back electromotive force of the inductive load. When the back electromotive force meets the clamp condition of the clamp detection module, the first bias voltage providing module provides a bias voltage to the second bias voltage providing module to activate the second bias voltage providing module to provide a bias voltage to the freewheeling control module, thereby enabling the freewheeling control module to generate a freewheeling path to release the energy of the inductive load.
2. The intelligent clamping circuit according to claim 1, characterized in that: The clamp detection module includes a diode unit, a first resistor and a second resistor; The first end of the diode unit is connected to the power supply voltage, the second end of the diode unit is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the first bias voltage providing module, and the second end of the first resistor is also connected to the second end of the second bias voltage providing module.
3. The intelligent clamping circuit according to claim 2, characterized in that: The diode unit includes a first diode group and a second diode group; The first diode group includes a first preset number of first diodes connected in series, and the second diode group includes a second preset number of second diodes connected in series; In the first diode group, the anode of the first diode farthest from the second diode group is connected to the power supply voltage; In the second diode group, an anode of a second diode farthest from the first diode group is connected to a first end of the first resistor; At the connection between the first diode group and the second diode group, the cathode of the first diode in the first diode group is connected to the cathode of the second diode in the second diode group.
4. The intelligent clamping circuit according to claim 3, characterized in that: The first preset number and the second preset number are determined based on a preset clamp of the clamp detection module.
5. The intelligent clamping circuit according to claim 1, characterized in that: The first bias voltage providing module includes a power consumption circuit; The drain of the power dissipation device is connected to the second end of the clamp detection module, the gate of the power dissipation device is connected to the source of the power dissipation device, and the source of the power dissipation device is connected to the third end of the second bias voltage providing module.
6. The intelligent clamping circuit according to claim 1, characterized in that: The second bias voltage providing module includes a high voltage tube and a third resistor; The drain of the high-voltage tube is connected to the power supply voltage, the gate of the high-voltage tube is connected to the third end of the clamp detection module, and the source of the high-voltage tube is connected to the second end of the freewheeling control module; Two ends of the third resistor are respectively connected to the gate of the freewheeling control module and the source of the freewheeling control module.
7. The intelligent clamping circuit according to claim 1, characterized in that: The freewheeling control module includes a power tube; The drain of the power tube is connected to the power supply voltage, the gate of the power tube is respectively connected to the third end of the second bias voltage providing module, and the source of the power tube is connected to the inductive load.
8. The intelligent clamping circuit according to claim 1, characterized in that: When the inductive load is powered off and the back electromotive force does not meet the clamping condition of the clamping detection module, the first bias voltage providing module controls the second bias voltage providing module to be in a closed state, so that the freewheeling control module is also in a closed state.
9. The intelligent clamping circuit according to claim 1, characterized in that: When the inductive load is in a normal working state, the first bias voltage providing module controls the second bias voltage providing module to be in a closed state, and the freewheeling control module is in a normal open and closed state.
10. A chip, characterized in that: The invention comprises an intelligent clamping circuit as described in any one of claims 1 to 9.