Input electronic safety circuit and device
By using a combination of comparator U1 and a switching unit in the input electronic fuse circuit, accurate detection and rapid protection of the target input unit are achieved, solving the problem of poor consistency in existing fuse circuits and improving the sensitivity to dangerous currents and the protection effect.
Patent Information
- Application Number
- CN202422733869.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-11-08
AI Technical Summary
Existing fuse circuits have poor consistency and are difficult to control temperature effects, resulting in insensitivity to dangerous currents.
An input electronic fuse circuit is adopted, which uses comparator U1 to monitor the target input unit in real time. Through the first and second switching units and the positive feedback unit, the abnormality is accurately detected and the circuit is quickly shut down. Combined with the protection circuit composed of resistors and switching transistors, the isolation between the target input unit and the target output terminal is achieved.
It achieves accurate detection and rapid protection of the target input unit, improves the sensitivity and consistency of the circuit, and avoids circuit damage caused by abnormalities.
Smart Images
Figure CN223527762U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of protection circuit, especially input electronic fuse circuit and device. BACKGROUND
[0002] In order to prevent the circuit short circuit and cause the circuit board and key device of electric equipment to be damaged, fuse and insurance switch are connected in series on the power line at present, when the power current exceeds normal value, it can reach the purpose of cutting off the power by fusing fuse or shutting off insurance switch to protect the circuit and key device of electric equipment. The biggest problem of using fuse and insurance switch to protect is that its consistency cannot satisfy people, speaking of the same type fuse or insurance switch, its threshold value of shutting off (fusing) current is not same in individual, temperature effect is difficult to control, causes not sensitive to dangerous current. Therefore, it is necessary to improve the prior art. SUMMARY
[0003] In view of the deficiencies in the prior art, the utility model provides an input electronic fuse circuit and device, solve the problem of poor consistency of fuse circuit in prior art, temperature effect is difficult to control, lead to not sensitive to dangerous current.
[0004] At least one embodiment of the utility model provides an input electronic fuse circuit, including: target input unit, target output end VIN, first switch unit, comparator U1 and second switch unit, wherein,
[0005] One end of the target input unit is connected with the first input end of the comparator U1 to provide input voltage for the first input end, and the second input end of the comparator U1 is connected with reference voltage;
[0006] The output end of the comparator U1 is connected with the control end of the second switch unit to control the conduction of the second switch unit;
[0007] The control end of the first switch unit is connected with the second switch unit to control the conduction of the first switch unit according to the conduction state of the second switch unit;
[0008] The other end of the target input unit is connected with the target output end VIN through the first switch unit.
[0009] The technical scheme disclosed by the utility model has at least the following beneficial effects:
[0010] Through the real-time monitoring of the target input unit by the first input end of the comparator U1, once the target input unit is short-circuited, the current voltage sharply rises until just the reference voltage, at this time, the output preset level of the output end of the comparator U1 is controlled to rapidly turn off the first switch unit and the second switch unit, and then the isolation between the target input unit and the target output end VIN is realized, obviously, compared with the prior art, the abnormality of the target input unit can be accurately detected, and the first switch unit is rapidly turned off, the consistency is better, and the sensitivity is better.
[0011] In the input electronic fuse circuit provided by one of the embodiments of the utility model, the circuit further comprises a positive feedback unit, wherein,
[0012] The positive feedback unit is connected with the output end of the comparator U1 and the first input end of the comparator U1 respectively, so as to provide the positive feedback voltage for the first input end of the comparator U1 when the output end of the comparator U1 outputs the preset level.
[0013] The technical scheme provided by the utility model has at least the following beneficial effects:
[0014] Through the setting of the positive feedback unit, when the output end of the comparator U1 outputs the preset level, the positive feedback voltage can be continuously provided for the first input end of the comparator U1, so that the output preset level of the output end of the comparator U1 is continuously output, and when the target input unit or the first input end of the comparator U1 is abnormal and is pulled down, the target input unit and the target output end VIN are connected, and the circuit is damaged.
[0015] In the input electronic fuse circuit provided by one of the embodiments of the utility model, the positive feedback unit comprises a third switch unit and a first power supply, wherein,
[0016] The first power supply is connected with the first input end of the comparator U1 through the third switch unit;
[0017] The output end of the comparator U1 is connected with the control end of the third switch unit, so as to control the conduction of the third switch unit when the output end outputs the preset level.
[0018] The technical scheme provided by the utility model has at least the following beneficial effects:
[0019] Through the above setting, when the output end of the comparator U1 outputs the preset level, the third switch unit is conducted, at this time, the first power supply provides the voltage for the first input end of the comparator U1 through the third switch unit, and then the output of the comparator U1 is locked.
[0020] In the input electronic fuse circuit provided by the utility model, the third switch unit comprises: a resistor R7, a resistor R8, a resistor R9 and a third switch tube Q3, wherein,
[0021] The first power supply is connected with the first input end of the comparator U1 through the resistor R7 and the two ends of the third switch tube Q3 in sequence.
[0022] The control end of the third switch tube Q3 is connected with the resistor R7 through the resistor R8, and the control end of the third switch tube Q3 is also connected with the output end of the comparator U1 through the resistor R9, so that the two ends of the third switch tube Q3 are turned on when the preset level is outputted from the output end.
[0023] The utility model discloses provide at least the following beneficial effects:
[0024] The resistor R9 provides the base current for the third switch tube Q3, and the resistor 7 and the resistor R8 provide the bias voltage for the third switch tube Q3, and also provide the positive feedback voltage to the first input end of the comparator U1.
[0025] In the input electronic fuse circuit provided by the utility model, the second switch unit comprises: a second power supply, a resistor R10, a resistor R11 and a second switch tube Q2, wherein,
[0026] The output end of the comparator U1 is connected with the control end of the second switch tube Q2 through the resistor R11, so as to control the disconnection of the second switch tube Q2 when the preset level is outputted from the output end.
[0027] The second power supply is connected with the control end of the second switch tube Q2 through the resistor R10 and the resistor R11 in sequence, so as to control the conduction of the second switch tube Q2 when the preset level is not outputted from the output end.
[0028] The utility model discloses provide at least the following beneficial effects:
[0029] The second power supply can provide the opening voltage for the control end of the second switch tube Q2 when the preset level is not outputted from the output end of the comparator U1.
[0030] In the input electronic fuse circuit provided by the utility model, the target input unit comprises: a first target input end DC, a second target input end X, a capacitor C2 and a resistor R3, wherein,
[0031] The first target input end DC is connected with the second target input end X through the capacitor C2, and the first target input end DC is connected with the target output end VIN through the first switch unit.
[0032] The second target input end X is connected with the first input end of the comparator U1 through the resistor R3.
[0033] The technical scheme provided by the utility model has at least the following beneficial effects:
[0034] The capacitor C2 can be used to filter the input voltage between the first target input end DC and the second target input end X, and the voltage of the target input unit is collected through the resistor R3.
[0035] In the input electronic fuse circuit provided by one of the embodiments of the utility model, the target input unit further comprises a resistor R4 and a capacitor C1, wherein,
[0036] The second target input end X is connected with the first input end of the comparator U1 through the resistor R3 and the capacitor C1 in sequence, and the second target input end X is further connected with the first input end of the comparator U1 through the resistor R4.
[0037] The technical scheme provided by the utility model has at least the following beneficial effects:
[0038] Through the resistor R4 and the capacitor C1, the signal isolation direct current between the first target input end DC and the second target input end X can be realized through the alternating current effect.
[0039] In the input electronic fuse circuit provided by one of the embodiments of the utility model, the reference voltage comprises a third power supply, a resistor R6, a resistor R5 and a capacitor C3, wherein,
[0040] The third power supply is connected with the common end through the resistor R6 and the resistor R5 in sequence.
[0041] The third power supply is further connected with the second input end of the comparator U1 through the resistor R6.
[0042] The capacitor C3 is connected with the resistor R5 in parallel.
[0043] The technical scheme provided by the utility model has at least the following beneficial effects:
[0044] Through the voltage division of the resistor R5 and the resistor R6, the second input end of the comparator U1 can be provided with a proper reference voltage.
[0045] In one embodiment of the present invention, an input electronic fuse circuit is provided, wherein the first switching unit includes: a first switching transistor Q1, a resistor R1, and a resistor R2, wherein,
[0046] The first switching transistor Q1 is a MOSFET, and the gate of the first switching transistor Q1 is connected to the second switching unit through the resistor R2.
[0047] The source of the first switch Q1 is connected to its gate through the resistor R1, and the target output terminal VIN is connected to the other end of the target input unit through the source and drain of the first switch Q1 in sequence.
[0048] This utility model also provides an input electronic safety device, including a device body and an input electronic safety circuit as described above disposed on the device body. Attached Figure Description
[0049] Figure 1 This is a detailed circuit diagram of an input electronic fuse circuit according to this utility model;
[0050] The attached diagram lists the components represented by each number as follows:
[0051] S1, target input unit; S2, first switch unit; S3, second switch unit; S4, positive feedback unit. Detailed Implementation
[0052] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.
[0053] This utility model provides an input electronic fuse circuit, please refer to [reference here]. Figure 1 As shown, it includes: a target input unit S1, a target output terminal VIN, a first switching unit S2, a comparator U1, and a second switching unit S3, wherein,
[0054] One end of the target input unit S1 is connected to the first input terminal of the comparator U1 to provide an input voltage to the first input terminal. The second input terminal of the comparator U1 is connected to a reference voltage. It should be understood that in this embodiment, the first input terminal of the comparator U1 is its cathode terminal, and the second input terminal of the comparator U1 is its anode terminal. At this time, when the voltage of the first input terminal of the comparator U1 is higher than the voltage of the second input terminal, the output terminal of the comparator U1 outputs a low level, and when the voltage of the first input terminal of the comparator U1 is lower than the voltage of the second input terminal, the output terminal of the comparator U1 outputs a high level.
[0055] Of course, the first input terminal can be an anode terminal, and the second input terminal can also be a cathode terminal, at which time adaptive modification of the subsequent circuit without requiring creative labor can be made;
[0056] The output terminal of the comparator U1 is connected with the control terminal of the second switch unit S3 to control the conduction of the second switch unit S3.
[0057] The control terminal of the first switch unit S2 is connected with the second switch unit S3 to control the conduction of the first switch unit S2 according to the conduction state of the second switch unit S3.
[0058] The other end of the target input unit S1 is connected with the target output terminal VIN through the first switch unit S2.
[0059] Through real-time monitoring of the target input unit S1 by the first input terminal of the comparator U1, once a short circuit occurs in the target input unit S1, the current voltage sharply rises until the reference voltage, at which time the output terminal of the comparator U1 controls the output of a preset level to quickly turn off the first switch unit S2 and the second switch unit S3, thereby realizing the isolation between the target input unit S1 and the target output terminal VIN. Obviously, compared with the prior art, the circuit can accurately detect the abnormality of the target input unit S1 and quickly turn off the first switch unit S2, has good consistency, and is more sensitive.
[0060] Specifically, the circuit further comprises a positive feedback unit S4, wherein,
[0061] The positive feedback unit S4 is connected with the output terminal of the comparator U1 and the first input terminal of the comparator U1 to provide a positive feedback voltage for the first input terminal of the comparator U1 when the output terminal of the comparator U1 outputs a preset level, wherein the preset level is a low level in this embodiment.
[0062] Through the setting of the positive feedback unit S4, when the output terminal of the comparator U1 outputs a low level, the first input terminal of the comparator U1 can be continuously provided with a positive feedback voltage, so that the output terminal of the comparator U1 continuously outputs a low level, avoiding the connection of the target input unit S1 and the target output terminal VIN when the first input terminal of the comparator U1 or the target input unit S1 is abnormally pulled low, and thereby damaging the circuit.
[0063] Specifically, the positive feedback unit S4 comprises a third switch unit and a first power supply, wherein the first power supply is represented by "VCC_2" in Figure 1 , and the first power supply simultaneously supplies power to the comparator U1;
[0064] The first power supply is connected with the first input end of the comparator U1 through the third switch unit;
[0065] The output end of the comparator U1 is connected with the control end of the third switch unit, so as to control the conduction of the third switch unit when the output end outputs low level.
[0066] Through the above setting, the third switch unit is conducted when the output end of the comparator U1 outputs low level, at this time, the first power supply provides voltage for the first input end of the comparator U1 through the third switch unit, and further locks the output of the comparator U1.
[0067] Specifically, the third switch unit comprises a resistor R7, a resistor R8, a resistor R9 and a third switch tube Q3, wherein the third switch tube Q3 is a PNP triode;
[0068] The first power supply is connected with the first input end of the comparator U1 through the resistor R7, the emitter of the third switch tube Q3 and the collector in sequence;
[0069] The base of the third switch tube Q3 is connected with the resistor R7 through the resistor R8, and the base of the third switch tube Q3 is also connected with the output end of the comparator U1 through the resistor R9, so as to make the both ends of the third switch tube Q3 conductive when the output end outputs low level.
[0070] The resistor R9 provides base current for the third switch tube Q3, the resistor 7 and the resistor R8 provide bias voltage for the collector and the emitter of the third switch tube Q3, and at the same time, provide positive feedback voltage to the first input end of the comparator U1.
[0071] Specifically, the second switch unit S3 comprises a second power supply, a resistor R10, a resistor R11 and a second switch tube Q2, wherein the second switch tube Q2 is an NPN triode, and the second power supply is represented by "VCC_1" in Figure 1 .
[0072] The output end of the comparator U1 is connected with the base of the second switch tube Q2 through the resistor R11, so as to control the disconnection of the emitter and the collector of the second switch tube Q2 when the output end outputs low level. The emitter of the second switch tube Q2 is connected with the common end;
[0073] The second power supply is connected with the base of the second switch tube Q2 through the resistor R10 and the resistor R11 in sequence, so as to control the conduction of the second switch tube Q2 when the output end outputs high level.
[0074] The second power supply can provide an opening voltage for the control end of the second switch tube Q2 when the output end of the comparator U1 does not output a low level.
[0075] Specifically, the target input unit S1 comprises a first target input end DC, a second target input end X, a capacitor C2 and a resistor R3, wherein,
[0076] The first target input end DC is connected with the second target input end X through the capacitor C2, and is connected with the target output end VIN through the first switch unit S2.
[0077] The second target input end X is connected with the first input end of the comparator U1 through the resistor R3.
[0078] It should be noted that the second target input end X located at the left side of the Figure 1 and the second target input end X located at the right side of the Figure 1 are the same point in actual distribution.
[0079] The capacitor C2 can be used to filter the input voltage between the first target input end DC and the second target input end X, and collect the voltage of the target input unit S1 through the resistor R3.
[0080] Specifically, the target input unit S1 further comprises a resistor R4 and a capacitor C1, wherein,
[0081] The second target input end X is connected with the first input end of the comparator U1 through the resistor R3 and the capacitor C1 in sequence, and is further connected with the first input end of the comparator U1 through the resistor R4.
[0082] Through the resistor R4 and the capacitor C1, the signal isolation direct current between the first target input end DC and the second target input end X can be realized through the effect of alternating current.
[0083] Specifically, the reference voltage comprises a third power supply, a resistor R6, a resistor R5 and a capacitor C3, wherein the third power supply is represented by "VREF" in the Figure 1 .
[0084] The third power supply is connected with the common end through the resistor R6 and the resistor R5 in sequence.
[0085] The third power supply is further connected with the second input end of the comparator U1 through the resistor R6.
[0086] The capacitor C3 is connected with the resistor R5 in parallel.
[0087] The voltage divider of the resistor R5 and the resistor R6 can provide a suitable reference voltage for the second input terminal of the comparator U1.
[0088] Specifically, the first switch unit S2 comprises a first switch tube Q1, a resistor R1 and a resistor R2.
[0089] The first switch tube Q1 is a MOS tube, and the gate of the first switch tube Q1 is connected with the second switch unit S3 through the resistor R2.
[0090] The source of the first switch tube Q1 is connected with the gate through the resistor R1, and the target output terminal VIN is connected with the other end of the target input unit S1 through the source and the drain of the first switch tube Q1.
[0091] Therefore, the above circuit has the following advantages:
[0092] The resistor R6 and the resistor R5 constitute a voltage divider circuit, the third power supply is divided to the anode terminal of the comparator U1, and the voltage at the cathode terminal of the comparator U1 is compared, the resistor R7, the resistor R8 and the resistor R9 provide the base current of the third switch tube Q3 and the positive feedback voltage to the cathode terminal of the comparator U1, the resistor R10 provides the pull-up voltage for the second switch tube Q2, the resistor R11 provides the base current for the second switch tube Q2, the resistor R1 and the resistor R2 provide the base voltage path for the first switch tube Q1, the first switch tube Q1 is an electronic fuse, the capacitor C2 is a filter capacitor, the resistor R3 is a sampling resistor, and the real-time current of the target input unit S1 is taken, at this time, the current flowing through the resistor R3 can be converted into voltage, and the resistor R4 and the capacitor C1 constitute an RC filter to filter the signal output by the target input unit S1 and output to the cathode terminal of the comparator U1.
[0093] At this time, the current of the target input unit S1 is detected through the sampling resistor R3, when the capacitor C2 is short-circuited, the current of the target input unit S1 increases, the voltage flowing through the resistor R3 rises, after being filtered by the resistor R4 and the capacitor C1, the voltage is output to the cathode terminal of the comparator U1, when the voltage exceeds the voltage at the anode terminal of the comparator U1, the output terminal of the comparator U1 outputs a low voltage, at this time, the third switch tube Q3 is turned on, the second switch tube Q2 is not turned on, and therefore the first switch tube Q1 is not turned on, so as to isolate the conduction of the target input unit S1 and the target output terminal VIN, and the resistor R7 and the third switch tube Q3 form a positive feedback circuit, which prevents the input voltage from being pulled down and short-circuited, and plays a protection role.
[0094] Conversely, when the capacitor C2 is normal, the target input unit S1 current is normal, the voltage flowing through the resistor R3 is filtered through the resistor R4 and the capacitor C1, and then reaches the cathode end of the comparator U1, which is lower than the voltage of the anode end of the comparator U1, so that the output end of the comparator U1 outputs a high level, at this time, the third switch tube Q3 is not conductive, the second switch tube Q2 is conductive, and therefore the first switch tube Q1 is conductive.
[0095] Through the setting of the comparator U1, the response speed of the circuit is very fast, so when the resistor R3 detects that the target input unit S1 has a short circuit abnormality, the protection function can be quickly realized.
[0096] The utility model also provides an input electronic fuse device, including device ontology and the configuration on the ontology like above-mentioned one kind of input electronic fuse circuit.
[0097] In the utility model, unless another definite provision and limit, the term "mount", "link", "connect", "fix" and so on term should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated, can be mechanical connection, also can be electric connection, can be direct connection, also can pass through intermediate medium indirectly connect, can be two element internal communication or two element's interaction relation, unless another definite limit, to the ordinary skill in the art, can understand the concrete meaning of above-mentioned term in the utility model according to specific circumstances.
[0098] In the description of the specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.
[0099] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the utility model, and the ordinary skilled in the art can change, modify, replace and modify the above-mentioned embodiments within the scope of the utility model.
Claims
1. An input electronic fuse circuit, characterized by The circuit comprises: a target input unit (S1), a target output terminal VIN, a first switch unit (S2), a comparator U1 and a second switch unit (S3), wherein one end of the target input unit (S1) is connected with a first input terminal of the comparator U1 to provide an input voltage for the first input terminal, and a second input terminal of the comparator U1 is connected with a reference voltage; an output terminal of the comparator U1 is connected with a control terminal of the second switch unit (S3) to control conduction of the second switch unit (S3); a control terminal of the first switch unit (S2) is connected with the second switch unit (S3) to control conduction of the first switch unit (S2) according to a conduction state of the second switch unit (S3); the other end of the target input unit (S1) is connected with the target output terminal VIN through the first switch unit (S2).
2. An input electronic fuse circuit according to claim 1, characterized in that The circuit further comprises a positive feedback unit (S4), wherein the positive feedback unit (S4) is connected with the output terminal of the comparator U1 and the first input terminal of the comparator U1 respectively to provide a positive feedback voltage for the first input terminal of the comparator U1 when the output terminal of the comparator U1 outputs a preset level.
3. An input electronic fuse circuit according to claim 2, characterized in that The positive feedback unit (S4) comprises a third switch unit and a first power supply, wherein the first power supply is connected with the first input terminal of the comparator U1 through the third switch unit; the output terminal of the comparator U1 is connected with a control terminal of the third switch unit to control conduction of the third switch unit when the output terminal outputs the preset level.
4. An input electronic fuse circuit according to claim 3, characterized in that The third switch unit comprises a resistor R7, a resistor R8, a resistor R9 and a third switch tube Q3, wherein the first power supply is connected with the first input terminal of the comparator U1 through the resistor R7 and the two ends of the third switch tube Q3 in sequence; the control terminal of the third switch tube Q3 is connected with the resistor R8 through the resistor R7, and the control terminal of the third switch tube Q3 is also connected with the output terminal of the comparator U1 through the resistor R9 to make the two ends of the third switch tube Q3 conductive when the output terminal outputs the preset level.
5. An input electronic fuse circuit according to claim 1, wherein The second switch unit (S3) comprises a second power supply, a resistor R10, a resistor R11 and a second switch tube Q2, wherein the output terminal of the comparator U1 is connected with the control terminal of the second switch tube Q2 through the resistor R11 to control disconnection of the second switch tube Q2 when the output terminal outputs the preset level; the second power supply is connected with the control terminal of the second switch tube Q2 through the resistor R10 and the resistor R11 in sequence to control conduction of the second switch tube Q2 when the output terminal does not output the preset level.
6. An input electronic fuse circuit according to any one of claims 1 to 5, characterized in that The target input unit (S1) comprises a first target input terminal DC, a second target input terminal X, a capacitor C2 and a resistor R3, wherein the first target input terminal DC is connected with the second target input terminal X through the capacitor C2, and the first target input terminal DC is connected with the target output terminal VIN through the first switch unit (S2). The second target input end X is connected with the first input end of the comparator U1 through the resistor R3.
7. An input electronic fuse circuit according to claim 6, characterized in that The target input unit (S1) further comprises a resistor R4 and a capacitor C1, wherein, The second target input end X is connected with the first input end of the comparator U1 through the resistor R3 and the capacitor C1 in sequence, and the second target input end X is further connected with the first input end of the comparator U1 through the resistor R4.
8. An input electronic fuse circuit according to claim 1, wherein The reference voltage comprises a third power supply, a resistor R6, a resistor R5 and a capacitor C3, wherein, The third power supply is connected with the common end through the resistor R6 and the resistor R5 in sequence. The third power supply is further connected with the second input end of the comparator U1 through the resistor R6. The capacitor C3 is connected with the resistor R5 in parallel.
9. An input electronic fuse circuit according to claim 1, wherein, The first switch unit (S2) comprises a first switch tube Q1, a resistor R1 and a resistor R2, wherein, The first switch tube Q1 is a mos tube, and the gate of the first switch tube Q1 is connected with the second switch unit (S3) through the resistor R2. The source of the first switch tube Q1 is connected with the gate through the resistor R1, and the target output end VIN is connected with the other end of the target input unit (S1) through the source and the drain of the first switch tube Q1 in sequence.
10. An input electronic fuse, characterized by The device comprises a device body and an input electronic fuse circuit as claimed in any one of claims 1 to 9 arranged on the body.