Undervoltage protection circuit based on hysteresis detection
By designing an undervoltage protection circuit based on hysteresis detection, the problem of repeated power supply switches caused by internal resistance of the supercapacitor module is solved, and the stable operation of the system and property safety are achieved.
Patent Information
- Application Number
- CN202421385025.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-06-17
AI Technical Summary
Due to internal resistance, the supercapacitor module repeatedly turns on and off the power supply, causing irreversible damage to the system and loss of user property.
A undervoltage protection circuit based on hysteresis detection is designed, and the voltage output state of the capacitor energy storage module is detected through the hysteresis detection module. The power switch module closes and disconnects based on the voltage output signals of the detection circuit and the capacitor storage module, and introduces a positive feedback network to prevent the switch from repeatedly oscillating.
It effectively prevents the power supply of supercapacitor modules from being repeatedly turned on and off due to internal resistance, ensures stable operation of the system, and avoids irreversible damage and property losses.
Smart Images
Figure CN222691375U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of protection circuits, in particular to an undervoltage protection circuit based on hysteresis detection. Background Art
[0002] As an emergency power supply supplement for power terminal products (concentrators, integrated terminals, etc.), supercapacitor modules collect and store electrical energy during normal operation of the system. When a power outage occurs, the supercapacitor module can maintain system operation and discharge continuously until low voltage shutdown.
[0003] However, due to the internal resistance of the supercapacitor module, when the supercapacitor module is discharged to a critical voltage to maintain the normal operation of the system, the supercapacitor module will cause the system to be in a state of repeated oscillation between shutdown and startup, which will cause irreversible damage to the system and cause huge property losses to users. Therefore, in view of the problem of repeated power on and off caused by the internal resistance of the current supercapacitor module, a new technology is needed to solve the current technical problem. Utility Model Content
[0004] The main purpose of the utility model is to solve the technical problem that the current super capacitor module repeatedly turns on and off the power supply due to internal resistance.
[0005] The first aspect of the utility model provides an undervoltage protection circuit based on hysteresis detection, and the undervoltage protection circuit based on hysteresis detection includes:
[0006] Capacitor energy storage module, hysteresis detection module, power switch module, power supply module;
[0007] The power switch module is used to perform on-off control on the power module according to the output voltage of the hysteresis detection module and the output voltage of the capacitor energy storage module. The power switch module includes: a switch MOS tube and a switch triode. The source of the switch MOS tube is connected to the capacitor energy storage module, the drain of the switch MOS tube is connected to the power module, the gate of the switch MOS tube is connected to the collector of the switch triode, the base of the switch triode is connected to the hysteresis detection module, the emitter of the switch triode is grounded, and the capacitor energy storage module is connected to the hysteresis detection module.
[0008] Optionally, in a first implementation method of the first aspect of the utility model, the hysteresis detection module includes: a detection MOS tube, a comparator, and a detection transistor, the first pin of the comparator is connected to a noise voltage, the second pin of the comparator is grounded, the third pin of the comparator is connected to the source of the detection MOS tube, the drain of the detection MOS tube is connected to a bias voltage, the gate of the detection MOS tube is connected to the collector of the detection transistor, the base of the detection transistor is connected to the fourth pin of the comparator, and the emitter of the detection transistor is grounded.
[0009] Optionally, in a second implementation of the first aspect of the utility model, the fourth pin of the comparator is also connected to the base of the switching transistor, and the fifth pin of the comparator is connected to the capacitor energy storage module.
[0010] Optionally, in a third implementation of the first aspect of the utility model, the model of the comparator includes: any one of TL331, LM2903DR, and LM321.
[0011] Optionally, in a fourth implementation of the first aspect of the utility model, the detection MOS tube includes: an N-type MOS tube.
[0012] Optionally, in a fifth implementation of the first aspect of the utility model, the N-type MOS tube includes: any one of CJ3400, SI2302, and AO3400.
[0013] Optionally, in a sixth implementation of the first aspect of the utility model, the switch MOS tube includes: a P-type MOS tube.
[0014] Optionally, in a seventh implementation of the first aspect of the utility model, the P-type MOS tube model includes: any one of CJQ13P04, CJ3401, and SI2301.
[0015] Optionally, in an eighth implementation of the first aspect of the utility model, the switching transistor includes: an NPN transistor.
[0016] Optionally, in a ninth implementation of the first aspect of the utility model, the NPN transistor includes: any one of MMBT3904, S9013, and S9014.
[0017] In the embodiment of the utility model, by utilizing a hysteresis circuit to detect the voltage output state of the capacitor energy storage module, the power switch module is closed and opened based on the voltage output signal of the detection circuit and the capacitor storage module, and by introducing a positive feedback network, the voltage detection has two threshold values to prevent repeated switching oscillations. Moreover, since the circuit does not require software intervention, it can stably and reliably solve the technical problem of repeated switching of the power supply due to internal resistance of the current supercapacitor module. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic diagram of an embodiment of an undervoltage protection circuit based on hysteresis detection in an embodiment of the utility model;
[0019] Figure 2 A schematic diagram of a specific embodiment of a capacitor energy storage module in an embodiment of the utility model;
[0020] Figure 3 A schematic diagram of a specific embodiment of a power switch module and a power module in an embodiment of the utility model;
[0021] Figure 4 A schematic diagram of a specific embodiment of a hysteresis detection module in an embodiment of the utility model;
[0022] Figure 5 It is a schematic diagram of a specific embodiment of the undervoltage protection circuit based on hysteresis detection in the embodiment of the utility model. DETAILED DESCRIPTION
[0023] The embodiment of the utility model provides an undervoltage protection circuit based on hysteresis detection.
[0024] The following will describe the embodiments of the present invention in more detail with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.
[0025] In the description of the embodiments disclosed in the present utility model, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.
[0026] For ease of understanding, the specific process of the embodiment of the utility model is described below. Figure 1 , an embodiment of the undervoltage protection circuit based on hysteresis detection in the embodiment of the utility model includes:
[0027] Capacitor energy storage module 10, hysteresis detection module 20, power switch module 30, power module 40;
[0028] The power switch module 10 is used to perform on-off control on the power module 40 according to the output voltage of the hysteresis detection module 20 and the output voltage of the capacitor energy storage module 30, wherein the hysteresis detection module 20 is connected to the capacitor energy storage module 10 and the power switch module 30, and the power switch module 30 is connected to the power module 40. The capacitor energy storage module 10 is used to power the system, the hysteresis detection module 20 is used to detect the current voltage state of the capacitor energy storage module 10, and output the result voltage to the power switch module 30, and the power switch module 30 is based on the voltage state of the capacitor energy storage module 10.
[0029] Please refer to Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a specific embodiment of a capacitor energy storage module in an embodiment of the present utility model. Figure 2 The medium capacitor energy storage module has 4 pins, of which pins 1 and 2 have an output voltage network of VC, and pins 3 and 4 are grounded.
[0030] Please refer to Figure 3 , Figure 3 This is a schematic diagram of a specific embodiment of a power switch module and a power module in an embodiment of the utility model. The power switch module 30 includes: a switch MOS tube Q1 and a switch transistor Q2. The source of the switch MOS tube Q1 is connected to the capacitor energy storage module 10, the drain of the switch MOS tube Q1 is connected to the power module 40, the gate of the switch MOS tube Q1 is connected to the collector C of the switch transistor Q2, the base B of the switch transistor Q2 is connected to the hysteresis detection module 20, the emitter E of the switch transistor Q2 is grounded, and the capacitor energy storage module 10 is connected to the hysteresis detection module 20.
[0031] Please refer to Figure 4 , Figure 4 This is a schematic diagram of a specific embodiment of the hysteresis detection module in the embodiment of the utility model. The hysteresis detection module 20 includes: a detection MOS tube Q3, a comparator U1, and a detection transistor Q4. The first pin of the comparator U1 is connected to the noise voltage VN, the second pin of the comparator U1 is grounded, the third pin IN+ of the comparator U1 is connected to the source of the detection MOS tube Q3, the drain of the detection MOS tube Q3 is connected to the bias voltage VP, the gate of the detection MOS tube Q3 is connected to the collector C of the detection transistor Q4, the base B of the detection transistor Q4 is connected to the fourth pin of the comparator U1, and the emitter E of the detection transistor Q4 is grounded.
[0032] Specifically, the fourth pin of the comparator U1 is also connected to the base B of the switch transistor Q2, and the fifth pin of the comparator U1 is connected to the capacitor energy storage module 10. In the circuit topology where the detection MOS tube Q3 is connected to the capacitor energy storage module 10, a resistor R5 and a resistor R2 can be connected, and the third pin IN+ of the comparator U1 is connected between the resistor R5 and the resistor R2.
[0033] Please refer to Figure 5 , Figure 5 This is a specific embodiment of the undervoltage protection circuit based on hysteresis detection in the embodiment of the utility model, and the working principle of the circuit based on the connection of the above modules is as follows:
[0034] When the voltage of the capacitor energy storage module 10 is higher than the threshold value VTH2, the hysteresis detection module 20 outputs a high-level signal to the power switch module 30; the power switch module 30 is used to control the output of the power switch module 30 to turn on according to the high-level signal of the hysteresis detection module 20, thereby maintaining the power supply to the system power supply 40 and turning on the system.
[0035] When the voltage of the capacitor energy storage module 10 is lower than the threshold value VTH1, the hysteresis detection module 20 outputs a low-level signal to the power switch module 30. The power switch module 30 is used to control the output of the power switch module 30 to be turned off according to the low-level signal of the hysteresis detection module 20, thereby disconnecting the power supply to the system power supply 40 and shutting down the system.
[0036] In this embodiment, since the hysteresis detection module 20 introduces positive feedback, the voltage detection threshold value VTH2 is higher than the threshold value VTH1. Therefore, the supercapacitor module undervoltage protection circuit and device based on the hysteresis circuit provided by the present invention realize timely and continuous undervoltage circuit protection, with high flexibility and a wider range of applications.
[0037] In specific implementation, the initial voltage of the capacitor energy storage module 10 is very low, and the in-phase input voltage VP of the comparator U1 is less than the reverse voltage VN. At this time, the level of the comparator U1 PIN4 is low, NPN Q2 and NPN Q4 work in the cut-off state, and PMOS Q1 works in the cut-off state, and the power supply to the system power supply 40 is disconnected, and the system is in a power-off state. NMOS Q3 is in a conducting state because the G pole is pulled up to VC through the resistor R7. Ignoring the conduction impedance of NMOS Q3, the resistor R6 is connected to the ground. At this time:
[0038]
[0039] When the voltage of the capacitor energy storage module 10 continues to rise to VP ≥ VN, the threshold value is:
[0040]
[0041]
[0042] The comparator U1 PIN4 level is high, NPN Q2, NPN Q4 work in saturated conduction state, PMOS Q1 works in conduction state, the power supply to the system power supply 40 is started, and the system is in power-on state. At the same time, NMOS Q3 is in cut-off state, and resistor R6 is disconnected from the ground. At this time:
[0043]
[0044] Assume that the main power supply of the system is off at this time, the capacitor energy storage module 10 starts to discharge, and VC gradually decreases to VP≤VN. At this time, the threshold value is:
[0045]
[0046]
[0047]
[0048] In summary, the present invention realizes that when the voltage of the capacitor energy storage module 10 is greater than the threshold voltage VTH2, the system starts to power on; when the voltage is less than the threshold voltage VTH1, the system power is disconnected. VTH2 is greater than VTH1, which prevents the overcapacitor module from undervoltage and causing repeated switching oscillations.
[0049] Component model description:
[0050] 1. The comparator models include: any one of TL331, LM2903DR, and LM321.
[0051] 2. The MOS tubes to be tested include: N-type MOS tubes, which include: any one of CJ3400, SI2302, and AO3400.
[0052] 3. The switch MOS tube includes: P-type MOS tube, and the P-type MOS tube models include: any one of CJQ13P04, CJ3401, and SI2301.
[0053] 4. The switching transistor includes: NPN transistor, and the NPN transistor includes: any one of MMBT3904, S9013, and S9014.
[0054] In the embodiment of the utility model, by utilizing a hysteresis circuit to detect the voltage output state of the capacitor energy storage module, the power switch module is closed and opened based on the voltage output signal of the detection circuit and the capacitor storage module, and by introducing a positive feedback network, the voltage detection has two threshold values to prevent repeated switching oscillations. Moreover, since the circuit does not require software intervention, it can stably and reliably solve the technical problem of repeated switching of the power supply due to internal resistance of the current supercapacitor module.
[0055] In addition, although each operation is described in a specific order, this should be understood as requiring such operation to be performed in the specific order shown or in a sequential order, or requiring that all illustrated operations should be performed to obtain desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation can also be implemented in multiple implementations individually or in any suitable sub-combination mode.
[0056] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.
Claims
1. An undervoltage protection circuit based on hysteresis detection, characterized in that: include: Capacitor energy storage module, hysteresis detection module, power switch module, power supply module; The power switch module is used to perform on-off control on the power module according to the output voltage of the hysteresis detection module and the output voltage of the capacitor energy storage module. The power switch module includes: a switch MOS tube and a switch triode. The source of the switch MOS tube is connected to the capacitor energy storage module, the drain of the switch MOS tube is connected to the power module, the gate of the switch MOS tube is connected to the collector of the switch triode, the base of the switch triode is connected to the hysteresis detection module, the emitter of the switch triode is grounded, and the capacitor energy storage module is connected to the hysteresis detection module.
2. The undervoltage protection circuit based on hysteresis detection according to claim 1, characterized in that: The hysteresis detection module includes: a detection MOS tube, a comparator, and a detection transistor. The first pin of the comparator is connected to a noise voltage, the second pin of the comparator is grounded, the third pin of the comparator is connected to the source of the detection MOS tube, the drain of the detection MOS tube is connected to a bias voltage, the gate of the detection MOS tube is connected to the collector of the detection transistor, the base of the detection transistor is connected to the fourth pin of the comparator, and the emitter of the detection transistor is grounded.
3. The undervoltage protection circuit based on hysteresis detection according to claim 2, characterized in that: The fourth pin of the comparator is also connected to the base of the switching transistor, and the fifth pin of the comparator is connected to the capacitor energy storage module.
4. The undervoltage protection circuit based on hysteresis detection according to any one of claims 2 or 3, characterized in that: The comparator model includes any one of TL331, LM2903DR and LM321.
5. The undervoltage protection circuit based on hysteresis detection according to claim 2, characterized in that: The detection MOS tube includes: an N-type MOS tube.
6. The undervoltage protection circuit based on hysteresis detection according to claim 5, characterized in that: The N-type MOS tube includes any one of: CJ3400, SI2302, and AO3400.
7. The undervoltage protection circuit based on hysteresis detection according to claim 1, characterized in that: The switch MOS tube includes: a P-type MOS tube.
8. The undervoltage protection circuit based on hysteresis detection according to claim 7, characterized in that: The P-type MOS tube models include: any one of CJQ13P04, CJ3401, and SI2301.
9. The undervoltage protection circuit based on hysteresis detection according to claim 1, characterized in that: The switch transistor includes: an NPN transistor.
10. The undervoltage protection circuit based on hysteresis detection according to claim 9, characterized in that: The NPN transistor includes any one of MMBT3904, S9013 and S9014.