Overcurrent protection circuit

Abstract

The embodiment of the utility model provides an overcurrent protection circuit, and relates to the technical field of circuits. The overcurrent protection circuit comprises a sampling unit, an analog-to-digital conversion module, an MOS tube, a load module and a control center. The sampling unit, the MOS tube and the load module are connected in series; the sampling unit is connected with the control center through the analog-to-digital conversion module. The control center is connected with the grid electrode of the MOS tube. The control center can manually or automatically configure a current value, so that the circuit realizes an over-current protection function with an adjustable current upper limit value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to an overcurrent protection circuit. BACKGROUND

[0002] In a circuit, in order to avoid the fault caused by overcurrent, overcurrent protection measures are needed, and the size of the current needs to be limited.

[0003] Different upper limit values of current may be needed in different situations.

[0004] How to design an overcurrent protection circuit with adjustable upper limit value of current is a technical problem to be solved by the present application. CONTENT OF THE INVENTION

[0005] The present application aims to provide an overcurrent protection circuit to realize the overcurrent protection function with adjustable upper limit value of current.

[0006] To achieve the above-mentioned purpose, the embodiments of the present application adopt the following technical solutions.

[0007] In a first aspect, the embodiments of the present application provide an overcurrent protection circuit, comprising a sampling unit, an analog-to-digital conversion module, a MOS tube, a load module and a control center.

[0008] The sampling unit, the MOS tube and the load module are connected in series.

[0009] The sampling unit is connected to the control center through the analog-to-digital conversion module, and the control center is connected to the gate of the MOS tube; the control center can manually or automatically configure the current value.

[0010] Optionally, the sampling unit comprises a sampling resistor.

[0011] The voltage of the sampling resistor is transmitted to the control center through the analog-to-digital conversion module.

[0012] Optionally, the sampling unit further comprises an operational amplifier.

[0013] The two input terminals of the operational amplifier are connected to the two ends of the resistor, and the output terminal of the operational amplifier is connected to the control center through the analog-to-digital conversion module.

[0014] Optionally, the operational amplifier is a programmable gain amplifier.

[0015] The two input terminals of the programmable gain amplifier are connected to the two ends of the resistor, and the output terminal of the programmable gain amplifier is connected to the control center through the analog-to-digital conversion module.

[0016] In a second aspect, the embodiments of the present application provide an overcurrent protection circuit, comprising a sampling module, a MOS tube, a load module, a control center and a control signal conversion module;

[0017] The sampling module, the MOS tube and the load module are connected in series.

[0018] The sampling module is connected to the control center, and the control center is connected to the gate of the MOS tube through the control signal conversion module; the control center can be manually or automatically configured with a current value.

[0019] Optionally, the control signal conversion module comprises a switch tube, a power supply and a resistance unit.

[0020] The positive pole of the power supply is connected to the negative pole of the power supply through the resistance unit to form a loop.

[0021] The resistance unit is connected to the gate of the MOS tube.

[0022] The resistance unit is also connected to the first end of the switch tube, and the second end of the switch tube is connected to one pole of the power supply.

[0023] The control end of the switch tube is connected to the control center.

[0024] Optionally, the positive voltage end of the resistance unit is connected to the gate of the MOS tube.

[0025] The positive voltage end of the resistance unit is connected to the first end of the switch tube, and the second end of the switch tube is connected to the negative pole of the power supply.

[0026] The control end of the switch tube is connected to the control center.

[0027] Optionally, the power supply comprises a current source.

[0028] Optionally, the sampling module comprises a sampling unit and an analog-to-digital conversion module.

[0029] The sampling unit, the MOS tube and the load module are connected in series.

[0030] The sampling unit is connected to the control center through the analog-to-digital conversion module, and the control center is connected to the gate of the MOS tube through the control signal conversion module.

[0031] Optionally, the sampling unit comprises a sampling resistance and a programmable gain amplifier.

[0032] The two input ends of the programmable gain amplifier are connected to the two ends of the resistance, and the output end of the programmable gain amplifier is connected to the control center through the analog-to-digital conversion module.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] The overcurrent protection circuit provided by the embodiment of the application can control the center to configure the overcurrent protection threshold value, trigger protection when the overcurrent protection threshold value is exceeded or reached, and the center can configure the overcurrent protection threshold value in a manner of manual configuration through hardware or automatic configuration according to condition judgment by software or a logic circuit, so that the circuit realizes the overcurrent protection function with an adjustable upper limit value of current. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of the drawings.

[0036] Figure 1 An overcurrent protection circuit schematic diagram provided by the embodiment of the application, in which a sampling unit 1, a MOS tube 4 and a load module 5 are connected in sequence;

[0037] Figure 2 An overcurrent protection circuit schematic diagram provided by the embodiment of the application, in which a load module 5, a MOS tube 4 and a sampling unit 1 are connected in sequence;

[0038] Figure 3 An overcurrent protection circuit schematic diagram provided by the embodiment of the application, which includes a sampling module 6, a MOS tube 4, a load module 5, a control center 3 and a control signal conversion module 7;

[0039] Figure 4 An overcurrent protection circuit schematic diagram provided by the embodiment of the application, in which a control signal conversion module 7 includes a switch tube 71, a power supply 72 and a resistance unit 73;

[0040] Figure 5 An overcurrent protection circuit schematic diagram provided by the embodiment of the application, which includes an enhanced NMOS tube;

[0041] Figure 6 An overcurrent protection circuit schematic diagram provided by the embodiment of the application, which includes an enhanced PMOS tube.

[0042] Explanation of reference signs:

[0043] 1 sampling unit

[0044] 11 sampling resistance

[0045] 12 operational amplifier

[0046] 2. Analog-to-Digital Conversion Module

[0047] 3. Control Center

[0048] 4 MOSFETs

[0049] 5 Load Modules

[0050] 6 Sampling Module

[0051] 7. Control Signal Conversion Module

[0052] 71 Switching transistor

[0053] 72 Power Supply

[0054] 73 resistor units Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described in the accompanying drawings can generally be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0057] In the description of this application, it should be noted that:

[0058] Relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations;

[0059] "Connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0060] like Figure 1 , Figure 1 An overcurrent protection circuit is shown, which includes a sampling unit 1, an analog-to-digital conversion module 2, a MOSFET 4, a load module 5, and a control center 3.

[0061] The sampling unit 1, the MOS tube 4 and the load module 5 have the following connection relationship: the sampling unit 1, the MOS tube 4 and the load module 5 are connected in series. The sampling unit 1 can include a sampling resistor, which converts the current flowing through the resistor into a voltage, and the voltage obtained from the sampling resistor represents the current in the circuit.

[0062] The voltage between the two ends of the sampling resistor can represent the current in the circuit.

[0063] The voltage obtained from the sampling resistor can be transmitted to the control center 3 through the analog-to-digital conversion module 2.

[0064] The sampling unit 1 can also include an operational amplifier, and the two input terminals of the operational amplifier are convenient for collecting the voltage between the two ends of the sampling resistor, and the two ends of the sampling resistor are connected to the two input terminals of the operational amplifier. The operational amplifier can have an amplification effect, realizing accurate detection of the current value.

[0065] The operational amplifier can be a programmable gain amplifier (PGA), and the gain of the programmable gain amplifier can be adjusted, so that the current limiting value of the circuit can be flexibly adjusted. The PGA can also realize functions such as gear configuration.

[0066] The connection order of the sampling unit 1, the MOS tube 4 and the load module 5 can be various:

[0067] Figure 1 Among them, the sampling unit 1, the MOS tube 4 and the load module 5 are connected in turn;

[0068] For example, Figure 2 , Figure 2 The load module 5, the MOS tube 4 and the sampling unit 1 are connected in turn.

[0069] The load module 5 can also be provided with multiple load modules, and the connection mode of the multiple load modules can be various:

[0070] The multiple load modules 5 can be connected in series, the multiple load modules 5 can be connected in parallel, and the multiple load modules 5 can be connected in a combination of series and parallel;

[0071] For example, when the load module 5 includes a first load and a second load connected in series, the connection order of the sampling unit 1, the MOS tube 4, the first load and the second load can be that the sampling unit 1, the MOS tube 4, the first load and the second load are connected in turn, or the first load, the sampling unit 1, the MOS tube 4 and the second load are connected in turn, and the like.

[0072] The sampling unit 1, the analog-digital conversion module 2, the control center 3 and the MOS tube 4 have the following connection relationship: the sampling unit 1 is connected to the control center 3 through the analog-digital conversion module 2, and the control center 3 is connected to the gate of the MOS tube 4. The control center 3 can control the conduction or cutoff of the MOS tube.

[0073] The control center 3 has the function of manually or automatically configuring the current value, so that the overcurrent protection threshold value can be configured through the control center 3, and the protection is triggered when the overcurrent protection threshold value is exceeded or reached. The control center 3 can configure the overcurrent protection threshold value in the form of manual configuration through hardware, for example, by adjusting the parameters of the control center 3 through a button, or adding a potentiometer with a knob, etc. It can also be automatically configured by software or logic circuit according to the condition judgment, so that the circuit realizes the overcurrent protection function with adjustable current upper limit value. The current upper limit value can also have the characteristic of dynamic adjustment.

[0074] As shown in Figure 3 , if the signal obtained by the sampling unit meets the input condition of the control center, for example, the control center can receive an analog signal or the control center is built-in with an analog-digital converter, then the analog-digital conversion module 2 can be omitted, and the overcurrent protection circuit includes the sampling module 6, the MOS tube 4, the load module 5, the control center 3 and the control signal conversion module 7. The sampling module 6 can be a sampling resistor, or can include other devices. The control signal conversion module 7 can convert the signal of the control center into a signal more suitable for driving the MOS tube 4.

[0075] The sampling module 6, the MOS tube 4 and the load module 5 have the following connection relationship: the sampling module 6, the MOS tube 4 and the load module 5 are connected in series.

[0076] The sampling module 6, the control center 3, the control signal conversion module 7 and the MOS tube 4 have the following connection relationship: the sampling module 6 is connected to the control center 3, and the control center 3 is connected to the gate of the MOS tube 4 through the control signal conversion module 7.

[0077] As shown in Figure 4 , the control signal conversion module 7 can include a switch tube 71, a power supply 72 and a resistance unit 73; the switch tube 71, the power supply 72 and the resistance unit 73 have the following connection relationship:

[0078] The positive pole of the power supply 72 is connected to the negative pole of the power supply 72 through the resistance unit 73 to form a loop; the negative pole of the power supply 72 can be a ground terminal;

[0079] The resistance unit 73 is connected to the gate of the MOS tube 4;

[0080] The resistance unit 73 is connected to the first end of the switch tube 71, and the second end of the switch tube 71 is connected to one pole of the power supply 72;

[0081] The control end of the switch tube 71 is connected to the control center 3.

[0082] As Figure 5 , the power supply 72 can be a constant current source, the resistance unit 73 can only include one resistance, and the switch tube 71 can be an enhancement mode NMOS tube, and the connection relationship is as follows:

[0083] The positive voltage end of the resistance unit 73 is connected to the gate of the MOS tube 4;

[0084] The positive voltage end of the resistance unit 73 is connected to the first end of the switch tube 71, and the second end of the switch tube 71 is connected to the virtual ground point;

[0085] The gate of the switch tube 71 is connected to the control center 3.

[0086] In the case of the switch tube 71 being cut off, the power supply 72 provides current for the resistance unit 73, and the voltage generated by the resistance unit 73 makes the MOS tube 4 conduct. In the case of the switch tube 71 being turned on, the current of the power supply 72 passes through the switch tube 71, and the voltage of the resistance unit 73 is not enough to make the MOS tube 4 conduct, thereby limiting the current of the load module 5.

[0087] As Figure 5 , Figure 5 An embodiment of the overcurrent protection circuit including the analog-digital conversion module 2 and the control signal conversion module 7 is shown, and the sampling module 6 can include the sampling unit 1 and the analog-digital conversion module 2.

[0088] The sampling unit 1, the MOS tube 4 and the load module 5 have the following connection relationship: the sampling unit 1, the MOS tube 4 and the load module 5 are connected in series.

[0089] The sampling unit 1, the analog-digital conversion module 2, the control center 3, the control signal conversion module 7 and the MOS tube 4 have the following connection relationship: the sampling unit 1 is connected to the control center 3 through the analog-digital conversion module 2, and the control center 3 is connected to the gate of the MOS tube 4 through the control signal conversion module 7.

[0090] As Figure 5 , the sampling unit 1 can include a sampling resistor 11 and an operational amplifier 12, and the operational amplifier can be a programmable gain amplifier.

[0091] Based on the same inventive concept, the edge can be replaced, for example, the NMOS tube in Figure 5 is replaced by a PMOS tube in the corresponding position, as Figure 6 .

[0092] Overall, the embodiment of the application provides an overcurrent protection circuit, and relates to the technical field of circuit. The overcurrent protection circuit comprises a sampling unit, an analog-digital conversion module, a MOS tube, a load module and a control center. The sampling unit, the MOS tube and the load module are connected in series. The sampling unit is connected to the control center through the analog-digital conversion module, and the control center is connected to the gate of the MOS tube. The sampling unit can be a resistor. The current is converted into a voltage signal by taking advantage of the easy-to-measure advantage of the voltage signal. The voltage signal can be selectively amplified according to requirements, and can be measured through ADC analog-digital conversion, so that the accurate detection of the current size is realized. The current signal quantized by the ADC is processed by the control center, and the overcurrent value can be configured by the control center, so that the configuration of the current limiting overcurrent value is realized, and it is ensured that the maximum value of the current of the circuit does not exceed a certain specific value.

[0093] The device and system embodiments described above are only schematic, and part or all of the modules can be selected to achieve the purpose of the embodiment of the present application. Those skilled in the art can understand and implement without creative labor.

[0094] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An overcurrent protection circuit, characterized by comprising: It comprises a sampling unit, an analog-digital conversion module, a MOS tube, a load module and a control center. The sampling unit, the MOS tube and the load module are connected in series. The sampling unit is connected to the control center through the analog-digital conversion module, and the control center is connected to the gate of the MOS tube; the control center can be manually or automatically configured with current value.

2. The overcurrent protection circuit of claim 1, wherein, The sampling unit comprises a sampling resistor. The voltage of the sampling resistor is transmitted to the control center through the analog-digital conversion module.

3. The overcurrent protection circuit of claim 2, wherein, The sampling unit further comprises an operational amplifier. The two input terminals of the operational amplifier are connected to the two ends of the sampling resistor, and the output terminal of the operational amplifier is connected to the control center through the analog-digital conversion module.

4. The overcurrent protection circuit of claim 3, wherein, The operational amplifier is a programmable gain amplifier. The two input terminals of the programmable gain amplifier are connected to the two ends of the sampling resistor, and the output terminal of the programmable gain amplifier is connected to the control center through the analog-digital conversion module.

5. An overcurrent protection circuit, characterized by It comprises a sampling module, a MOS tube, a load module, a control center and a control signal conversion module. The sampling module, the MOS tube and the load module are connected in series. The sampling module is connected to the control center, and the control center is connected to the gate of the MOS tube through the control signal conversion module; the control center can be manually or automatically configured with current value.

6. The overcurrent protection circuit of claim 5, wherein, The control signal conversion module comprises a switch tube, a power supply and a resistor unit. The positive pole of the power supply is connected to the negative pole of the power supply through the resistor unit to form a loop. The resistor unit is connected to the gate of the MOS tube. The resistor unit is also connected to the first end of the switch tube, and the second end of the switch tube is connected to one pole of the power supply. The control end of the switch tube is connected to the control center.

7. The overcurrent protection circuit of claim 6, wherein, The positive voltage end of the resistor unit is connected to the gate of the MOS tube. The positive voltage end of the resistor unit is connected to the first end of the switch tube, and the second end of the switch tube is connected to the negative pole of the power supply. The control end of the switch tube is connected to the control center.

8. The overcurrent protection circuit of claim 6, wherein, The power supply comprises a current source.

9. The overcurrent protection circuit of claim 5, wherein, The sampling module comprises a sampling unit and an analog-digital conversion module. The sampling unit, the MOS tube and the load module are connected in series. The sampling unit is connected to the control center through the analog-digital conversion module, and the control center is connected to the gate of the MOS tube through the control signal conversion module.

10. The overcurrent protection circuit of claim 9, wherein, The sampling unit comprises a sampling resistor and a programmable gain amplifier. The two input terminals of the programmable gain amplifier are connected to the two ends of the sampling resistor, and the output terminal of the programmable gain amplifier is connected to the control center through the analog-digital conversion module.

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