CN216530526U - Short-circuit protection circuit and electronic device - Google Patents
Short-circuit protection circuit and electronic device Download PDFInfo
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- CN216530526U CN216530526U CN202122551849.6U CN202122551849U CN216530526U CN 216530526 U CN216530526 U CN 216530526U CN 202122551849 U CN202122551849 U CN 202122551849U CN 216530526 U CN216530526 U CN 216530526U
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Abstract
The application provides a short-circuit protection circuit, includes: the voltage stabilizer, the detection circuit and the control circuit; the voltage stabilizer is used for receiving a first voltage output by an external power supply and converting the first voltage into a second voltage to supply power to the electronic equipment; the detection circuit is used for detecting the second voltage and outputting a detection signal to the control circuit according to the voltage value of the second voltage; the control circuit is used for switching on or switching off the electric connection between the external power supply and the voltage stabilizer according to the detection signal. The application also provides an electronic device. From this, the short-circuit protection circuit that this application provided can be through the output voltage who detects the stabiliser to switch on or break off the stabiliser is connected with an external power source's electricity, controls the input voltage of stabiliser, can avoid the stabiliser because the output short circuit produces too big electric current, causes circuit ageing and damage.
Description
Technical Field
The application relates to the technical field of short-circuit protection, in particular to a short-circuit protection circuit and electronic equipment.
Background
With the development of circuit technology, a Low-dropout Linear-regulator (LDO) is widely used in electronic devices to convert a high-voltage input voltage into a stable Low voltage for supplying power to the electronic devices, however, a protection and buffer circuit is absent between the input voltage and the output voltage of the LDO, which may cause a short circuit at the output end of the LDO, and an output current at the output end of the LDO is too large, which may cause aging and damage of a circuit system.
SUMMERY OF THE UTILITY MODEL
Accordingly, there is a need for a short-circuit protection circuit applied to a voltage regulator, which can detect an output voltage of the voltage regulator, so as to connect or disconnect the voltage regulator to an external power supply to control an input voltage of the voltage regulator, and can prevent the voltage regulator from generating an excessive current due to a short circuit at an output terminal, thereby preventing the circuit from aging and damage.
A first aspect of an embodiment of the present application provides a short-circuit protection circuit, where the short-circuit protection circuit includes a voltage regulator, a detection circuit, and a control circuit;
the voltage stabilizer is electrically connected with the external power supply and the electronic equipment and is used for receiving a first voltage output by the external power supply and converting the first voltage into a second voltage to supply power to the electronic equipment;
the detection circuit is electrically connected with the voltage stabilizer and used for detecting the second voltage and outputting a detection signal to the control circuit according to the voltage value of the second voltage;
the control circuit is electrically connected with the detection circuit, the external power supply and the voltage stabilizer and used for switching on or switching off the electrical connection between the external power supply and the voltage stabilizer according to the detection signal.
In one possible implementation manner, the voltage regulator includes a reference power supply, and the voltage regulator compares the second voltage with a reference voltage output by the reference power supply and adjusts the magnitude of the second voltage according to a comparison result.
In a possible implementation manner, when the second voltage is less than or equal to a threshold, the detection circuit outputs a detection signal of a first level, and when the second voltage is greater than the threshold, the detection circuit outputs a detection signal of a second level.
In a possible implementation manner, the control circuit turns on the electrical connection between the external power supply and the voltage regulator according to the detection signal of the second level, and the control circuit turns off the electrical connection between the external power supply and the voltage regulator according to the detection signal of the first level.
In one possible implementation, the detection circuit includes a diode (D1), a first switch (T3), a cathode of the diode (D1) receives the second voltage, an anode of the diode (D1) is electrically connected to a first terminal of the first switch (T3), and a second terminal of the first switch (T3) is grounded;
the first switch (T3) is an NPN type triode, the first end of the first switch (T3) is the base electrode of the triode, and the second end of the first switch (T3) is the emitting electrode of the triode.
In a possible implementation manner, the detection circuit further includes a first resistor (R3), a second resistor (R2), and a second switch (T4), a first end of the first resistor (R3) is electrically connected to a first end of the first switch (T3) and an anode of the diode (D1), a first end of the second resistor (R2) is electrically connected to a first end of the second switch (T4), a second end of the second switch (T4) is grounded, and a third end of the second switch (T4) is electrically connected to a second end of the first resistor (R3);
the second switch is an NPN type triode, a first end of the second switch (T4) is a base electrode of the triode, a second end of the second switch (T4) is an emitting electrode of the triode, and a third end of the second switch (T4) is a collector electrode of the triode.
In a possible implementation manner, the control circuit includes a third resistor (R5), a fourth resistor (R6), and a third switch (T2), a first end of the third switch (T2) is electrically connected to a first end of the third resistor (R5), a second end of the third resistor (R5) is electrically connected to a third end of the second switch (T4) and a second end of the first resistor (R3), a second end of the third switch (T2) is grounded, and a third end of the third switch (T2) is electrically connected to a first end of the fourth resistor (R6);
the third switch (T2) is an NPN type triode, the first end of the third switch (T2) is the base electrode of the triode, the second end of the third switch (T2) is the emitting electrode of the triode, and the third end of the third switch (T2) is the collector electrode of the triode.
In one possible implementation manner, the control circuit further includes a fourth switch (T5), a fifth switch (T1), a second terminal of the fourth resistor (R6) is electrically connected to the first terminal of the fourth switch (T5), a second terminal of the fourth switch (T5) is electrically connected to the first terminal of the fifth switch (T1), a third terminal of the fourth switch (T5) is electrically connected to the voltage regulator, a second terminal of the fifth switch (T1) receives the first voltage, and a third terminal of the fifth switch (T1) is electrically connected to the voltage regulator;
the fourth switch (T5) is a PNP type triode, the first end of the fourth switch (T5) is the base electrode of the triode, the second end of the fourth switch (T5) is the emitting electrode of the triode, and the third end of the fourth switch (T5) is the collector electrode of the triode;
the fifth switch (T1) is a P-channel MOS transistor, the first end of the fifth switch (T1) is the grid electrode of the MOS transistor, the second end of the fifth switch (T1) is the source electrode of the MOS transistor, and the third end of the fifth switch (T1) is the drain electrode of the MOS transistor.
In a possible implementation manner, the voltage regulator further includes a fifth resistor (R7), a sixth resistor (R8), a comparator (U1), a first end of the fifth resistor (R7) receives the second voltage, a second end of the fifth resistor (R7) is electrically connected to the positive input end of the comparator (U1) and the first end of the sixth resistor (R8), a second end of the sixth resistor (R8) is electrically connected to the negative pole of the reference power supply, the second end of the sixth resistor (R8) is grounded, and the positive pole of the reference power supply is electrically connected to the negative input end of the comparator (U1).
A second aspect of embodiments of the present application provides an electronic device including a short-circuit protection circuit as described in any one of the above.
Therefore, the short-circuit protection circuit and the electronic equipment provided by the embodiment of the application can be used for switching on or off the voltage stabilizer through detecting the output voltage of the voltage stabilizer, so that the input voltage of the voltage stabilizer is controlled, and the phenomenon that the voltage stabilizer generates overlarge current due to short circuit of an output end to cause circuit aging and damage can be avoided.
Drawings
Fig. 1 is an electronic device provided in an embodiment of the present application.
Fig. 2 is a circuit diagram of a short-circuit protection circuit according to an embodiment of the present application operating in a normal mode.
Fig. 3 is a circuit diagram of a short-circuit protection circuit operating in an output short-circuit mode according to an embodiment of the present application.
Description of the main elements
Short-circuit protection circuit 100
Resistors R1, R2, R3, R4, R5, R6, R7 and R8
Triodes T2, T3, T4 and T5
Diode D1
PMOS transistor T1
Comparator U1
The following detailed description will further illustrate the utility model in conjunction with the above-described figures.
Detailed Description
In the embodiments of the present application, the terms "first", "second", and the like are used only for distinguishing different objects, and are not intended to indicate or imply relative importance, nor order to indicate or imply order. For example, a first application, a second application, etc. is used to distinguish one application from another application and not to describe a particular order of applications, and features defined as "first" and "second" may explicitly or implicitly include one or more of the features.
Referring to fig. 1, fig. 1 illustrates an electronic device 200 according to an embodiment of the present application.
In this embodiment, the electronic device 200 includes a short-circuit protection circuit 100 and an external power source 40, and the short-circuit protection circuit 100 includes a detection circuit 10, a control circuit 20 and a voltage regulator 30.
In some embodiments, the electronic device 200 may be an electronic device such as a mobile phone, a POS device, a handheld code scanning gun, a handheld printer, an electronic smoking set, a remote controller, a bluetooth headset bin, a tablet computer, or an electronic component such as a radio frequency amplifier, an integrated circuit chip, or the like.
The voltage regulator 30 may be electrically connected to the external power source 40, and is configured to receive the first voltage output by the external power source 40 and convert the first voltage into a second voltage to power the electronic device 200. In some embodiments, voltage regulator 30 may be a Low-dropout Linear-regulator (LDO).
In some embodiments, the voltage regulator 30 may be electrically connected to a reference voltage source, and the voltage regulator 30 may receive a reference voltage output by the reference voltage source and compare the second voltage with the reference voltage to adjust the magnitude of the second voltage according to the comparison result. It will be appreciated that the voltage regulator 30 has a feedback regulation function.
In this embodiment, the detection circuit 10 is electrically connected to the voltage regulator 30 and the control circuit 20, and is configured to detect the second voltage output by the voltage regulator 30, and output a detection signal to the control circuit 20 according to the detected voltage value of the second voltage. If the detection circuit 10 detects that the second voltage output by the voltage regulator 30 is less than or equal to a threshold, the detection circuit 10 determines that the output terminal of the voltage regulator 30 is short-circuited and outputs a detection signal of a first level to the control circuit 20, and if the detection circuit 10 detects that the output voltage of the voltage regulator 30 is greater than the threshold, the detection circuit 10 determines that the output terminal of the voltage regulator 30 is not short-circuited and outputs a detection signal of a second level to the control circuit 20.
In some embodiments, the threshold may be zero.
The control circuit 20 is electrically connected to the voltage regulator 30 and the external power source 40, and is configured to receive the detection signal output by the detection circuit 10, and turn on or off the electrical connection between the voltage regulator 30 and the external power source 40 according to the detection signal.
Therefore, when the output end of the voltage stabilizer 30 is short-circuited, the output current of the voltage stabilizer 30 is too large, which may cause the problem of circuit aging and damage, and the short-circuit protection circuit 100 may detect the output voltage of the voltage stabilizer 30, thereby controlling the input voltage of the voltage stabilizer 30 by turning on or off the electrical connection between the voltage stabilizer 30 and the external power supply, and avoiding the voltage stabilizer 30 from generating too large current due to the short-circuited output end.
Referring to fig. 2, fig. 2 is a circuit diagram of the short-circuit protection circuit 100 under a normal operating condition of the output terminal of the voltage regulator 30. As shown in fig. 2, the detection circuit 10 includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a transistor T3, a transistor T4, and a diode D1, wherein, the resistor R3 is a first resistor, the resistor R2 is a second resistor, the transistor T3 is a first switch, the transistor T4 is a second switch, a first end of the resistor R1 receives a first voltage VIN, a first end of the resistor R1 is electrically connected to a first end of the resistor R4, a second end of the resistor R1 is electrically connected to a first end of the resistor R3 and a collector of the transistor T4, an emitter of the transistor T4 is grounded, a base of the transistor T4 is electrically connected to a first end of the resistor R2, a second end of the resistor R2 is electrically connected to a second end of the resistor R4 and a collector of the transistor T3, a second end of the resistor R3 is electrically connected to a base of the transistor T3, an emitter of the transistor T3 is grounded, a cathode of the diode D1 receives the second voltage VOUT, and an anode of the diode D1 is electrically connected to a second end of the resistor R3 and a base of the transistor T3.
In this embodiment, the transistor T2, the transistor T3, and the transistor T4 are all NPN transistors, and the transistor T5 is a PNP transistor.
The voltage regulator 30 includes a resistor R7, a resistor R8, and a comparator U1, wherein the resistor R7 is a fifth resistor, the resistor R8 is a sixth resistor, a first end of the resistor R7 receives the second voltage VOUT, a first end of the resistor R7 is electrically connected to the cathode of the diode D1 and the drain of the PMOS transistor T1, a second end of the resistor R7 is electrically connected to the first end of the resistor R8 and the positive input end of the comparator U1, a negative input end of the comparator U1 receives the reference voltage VREF outputted by the reference power supply, a second end of the resistor R8 is grounded, a second end of the resistor R8 is electrically connected to the negative electrode of the reference power supply, and an output end of the comparator U1 is electrically connected to the collector of the transistor T5.
In this embodiment, when the output terminal of the voltage regulator 30 is not short-circuited, the second voltage VOUT is a first voltage value (e.g., 5V), the cathode and anode voltages of the diode D1 are both high levels, so that the transistor T3 is turned on, the collector voltage of the transistor T3 is low level, the transistor T4 is turned off, the detection signal is a second level (e.g., high level), the transistor T2 is turned on, the collector voltage of the transistor T2 is low level, the transistor T5 is turned on, the PMOS transistor T1 is turned on, the PMOS transistor T1 controls the drain voltage (i.e., the second voltage VOUT) according to the comparison voltage output by the comparator U1, and the voltage regulator 30 operates normally.
Referring to fig. 3, fig. 3 is a circuit diagram illustrating the short-circuit protection circuit 100 under a condition that the output terminal of the voltage regulator 30 is short-circuited.
In this embodiment, when the output terminal of the voltage regulator 30 is short-circuited, the second voltage VOUT is a second voltage value (e.g. zero), the cathode and anode voltages of the diode D1 are both low levels, so the transistor T3 is turned off, the collector voltage of the transistor T3 is high level, the transistor T4 is turned on, the detection signal is a first level (e.g. low level), the transistor T2 is turned off, the collector voltage of the transistor T2 is high level, the transistor T5 is turned off, and the PMOS transistor T1 is turned off, so that when the output terminal of the voltage regulator 30 is short-circuited, the PMOS transistor T1 can electrically disconnect the external power supply from the voltage regulator 30, so as to prevent the voltage regulator 30 from generating excessive current due to short-circuiting, and thus preventing the circuit from aging and being damaged.
It should be understood by those skilled in the art that the above embodiments are only for illustrating the present application and are not used as limitations of the present application, and that suitable modifications and changes of the above embodiments are within the scope of the claims of the present application as long as they are within the spirit and scope of the present application.
Claims (10)
1. A short-circuit protection circuit is characterized by comprising a voltage stabilizer, a detection circuit and a control circuit;
the voltage stabilizer is electrically connected with an external power supply and the electronic equipment and is used for receiving a first voltage output by the external power supply and converting the first voltage into a second voltage to supply power to the electronic equipment;
the detection circuit is electrically connected with the voltage stabilizer and used for detecting the second voltage and outputting a detection signal to the control circuit according to the voltage value of the second voltage;
the control circuit is electrically connected with the detection circuit, the external power supply and the voltage stabilizer and used for switching on or switching off the electrical connection between the external power supply and the voltage stabilizer according to the detection signal.
2. The short-circuit protection circuit of claim 1, wherein the voltage regulator includes a reference power supply, and wherein the voltage regulator compares the second voltage with a reference voltage output by the reference power supply and adjusts the magnitude of the second voltage according to the comparison.
3. The short-circuit protection circuit of claim 1, wherein the detection circuit outputs a first level of detection signal when the second voltage is less than or equal to a threshold value, and outputs a second level of detection signal when the second voltage is greater than the threshold value.
4. The short-circuit protection circuit according to claim 3, wherein the control circuit turns on the electrical connection between the external power supply and the voltage regulator according to the detection signal of the second level, and the control circuit turns off the electrical connection between the external power supply and the voltage regulator according to the detection signal of the first level.
5. The short-circuit protection circuit of claim 1, wherein the detection circuit comprises a diode (D1), a first switch (T3), a cathode of the diode (D1) receiving the second voltage, an anode of the diode (D1) being electrically connected to a first terminal of the first switch (T3), a second terminal of the first switch (T3) being connected to ground;
the first switch (T3) is an NPN type triode, the first end of the first switch (T3) is the base electrode of the triode, and the second end of the first switch (T3) is the emitting electrode of the triode.
6. The short-circuit protection circuit of claim 5, wherein the detection circuit further comprises a first resistor (R3), a second resistor (R2), and a second switch (T4), wherein a first terminal of the first resistor (R3) is electrically connected to a first terminal of the first switch (T3) and an anode of the diode (D1), a first terminal of the second resistor (R2) is electrically connected to a first terminal of the second switch (T4), a second terminal of the second switch (T4) is grounded, and a third terminal of the second switch (T4) is electrically connected to a second terminal of the first resistor (R3);
the second switch is an NPN type triode, a first end of the second switch (T4) is a base electrode of the triode, a second end of the second switch (T4) is an emitting electrode of the triode, and a third end of the second switch (T4) is a collector electrode of the triode.
7. The short-circuit protection circuit of claim 6, wherein the control circuit comprises a third resistor (R5), a fourth resistor (R6), and a third switch (T2), wherein a first terminal of the third switch (T2) is electrically connected to a first terminal of the third resistor (R5), a second terminal of the third resistor (R5) is electrically connected to a third terminal of the second switch (T4) and a second terminal of the first resistor (R3), a second terminal of the third switch (T2) is grounded, and a third terminal of the third switch (T2) is electrically connected to a first terminal of the fourth resistor (R6);
the third switch (T2) is an NPN type triode, the first end of the third switch (T2) is the base electrode of the triode, the second end of the third switch (T2) is the emitting electrode of the triode, and the third end of the third switch (T2) is the collector electrode of the triode.
8. The short-circuit protection circuit of claim 7, wherein the control circuit further comprises a fourth switch (T5), a fifth switch (T1), a second terminal of the fourth resistor (R6) is electrically connected to the first terminal of the fourth switch (T5), a second terminal of the fourth switch (T5) is electrically connected to the first terminal of the fifth switch (T1), a third terminal of the fourth switch (T5) is electrically connected to the voltage regulator, a second terminal of the fifth switch (T1) receives the first voltage, and a third terminal of the fifth switch (T1) is electrically connected to the voltage regulator;
the fourth switch (T5) is a PNP type triode, the first end of the fourth switch (T5) is the base electrode of the triode, the second end of the fourth switch (T5) is the emitting electrode of the triode, and the third end of the fourth switch (T5) is the collector electrode of the triode;
the fifth switch (T1) is a P-channel MOS transistor, the first end of the fifth switch (T1) is the grid electrode of the MOS transistor, the second end of the fifth switch (T1) is the source electrode of the MOS transistor, and the third end of the fifth switch (T1) is the drain electrode of the MOS transistor.
9. The short-circuit protection circuit of claim 2, wherein the voltage regulator further comprises a fifth resistor (R7), a sixth resistor (R8), a comparator (U1), a first end of the fifth resistor (R7) receives the second voltage, a second end of the fifth resistor (R7) is electrically connected to the positive input end of the comparator (U1) and the first end of the sixth resistor (R8), a second end of the sixth resistor (R8) is electrically connected to the negative terminal of the reference power supply, and a second end of the sixth resistor (R8) is grounded, and the positive terminal of the reference power supply is electrically connected to the negative input end of the comparator (U1).
10. An electronic device, characterized in that the electronic device comprises a short-circuit protection circuit according to any of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122551849.6U CN216530526U (en) | 2021-10-22 | 2021-10-22 | Short-circuit protection circuit and electronic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122551849.6U CN216530526U (en) | 2021-10-22 | 2021-10-22 | Short-circuit protection circuit and electronic device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216530526U true CN216530526U (en) | 2022-05-13 |
Family
ID=81524222
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122551849.6U Active CN216530526U (en) | 2021-10-22 | 2021-10-22 | Short-circuit protection circuit and electronic device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216530526U (en) |
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2021
- 2021-10-22 CN CN202122551849.6U patent/CN216530526U/en active Active
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