CN110265975B - IC chip protection circuit - Google Patents
IC chip protection circuit Download PDFInfo
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- CN110265975B CN110265975B CN201910385723.0A CN201910385723A CN110265975B CN 110265975 B CN110265975 B CN 110265975B CN 201910385723 A CN201910385723 A CN 201910385723A CN 110265975 B CN110265975 B CN 110265975B
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- 230000000087 stabilizing effect Effects 0.000 claims abstract description 35
- 238000005070 sampling Methods 0.000 claims abstract description 31
- 238000010586 diagram Methods 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/20—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment
- H02H7/205—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment for controlled semi-conductors which are not included in a specific circuit arrangement
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention provides an IC chip protection circuit, which includes: the sampling comparison circuit, the control circuit, the switching circuit and the IC chip feedback circuit; the sampling comparison circuit is used for connecting the load end to acquire a voltage value of the load end, and comparing the voltage value with a preset voltage stabilizing value to determine whether the load end is in an under-voltage or short-circuit state; the control circuit is connected with the sampling comparison circuit and is used for generating a voltage limiting instruction and sending the voltage limiting instruction to the switching circuit when the load end is in an under-voltage or short-circuit state; the switching circuit is connected with the IC chip feedback circuit and is used for limiting the voltage transmitted to the IC chip feedback circuit by the load end after receiving the voltage limiting instruction; the IC chip feedback circuit is connected with the load end and is used for feeding back an output signal of the load end to the IC chip. The IC chip protection circuit can reduce the voltage of the feedback signal transmitted to the IC chip by the load end when the load is undervoltage or short-circuited, and avoid damage caused by overlarge voltage of the IC chip.
Description
Technical Field
The invention relates to the field of switching power supplies, in particular to an IC chip protection circuit.
Background
In the prior art, an IC chip (IC, INTEGRATED CIRCUIT, integrated circuit) is generally used to control the output of the load terminal, and the IC chip includes a large number of microelectronic components, such as transistors, resistors, capacitors, and the like.
When the IC chip is used for controlling the load end, the IC chip also needs to acquire the output signal of the load end as feedback. Under the condition of undervoltage or short circuit of the load end, the current output by the load end can be instantaneously increased, so that the signal voltage fed back to the IC chip is increased, and the IC chip is damaged.
In the prior art, a circuit for protecting an IC chip during feedback at a load end is lacking.
Disclosure of Invention
In view of the above, the present invention provides an IC chip protection circuit, so as to reduce the voltage of a feedback signal transmitted from a load terminal to an IC chip when the load is under-voltage or short-circuited, and avoid damage caused by excessive voltage of the IC chip.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
An IC chip protection circuit comprises a sampling comparison circuit, a control circuit, a switch circuit and an IC chip feedback circuit;
the sampling comparison circuit is used for connecting a load end to acquire a voltage value of the load end, comparing the voltage value with a preset voltage stabilizing value and determining whether the load end is in an under-voltage or short-circuit state;
The control circuit is connected with the sampling comparison circuit and is used for generating a voltage limiting instruction to be sent to the switch circuit when the load end is in an under-voltage or short-circuit state;
the switch circuit is connected with the IC chip feedback circuit and is used for limiting the voltage transmitted to the IC chip feedback circuit by the load end after receiving the voltage limiting instruction;
the IC chip feedback circuit is connected with the load end and is used for feeding back an output signal of the load end to the IC chip.
Preferably, in the IC chip protection circuit, the sampling comparison circuit includes a first resistor, a second resistor, a voltage regulator, and a first triode;
One end of the first resistor is connected with the positive electrode of the load end, and the other end of the first resistor is connected with the voltage stabilizing tube and is used for transmitting the collected voltage value of the load end to the voltage stabilizing tube;
the voltage stabilizing tube is connected with the emitter of the first triode and is used for conducting the voltage stabilizing tube and the first triode when the voltage value is larger than the voltage stabilizing value of the voltage stabilizing tube;
the base electrode of the first triode is connected with the second resistor, and the other end of the second resistor is connected with the negative electrode of the load end;
And the collector electrode of the first triode is connected with the control circuit and is used for outputting a driving voltage to the control circuit when the first triode is conducted.
Preferably, in the IC chip protection circuit, the control circuit includes a second triode, a third triode, and a driving power supply;
the base electrode of the second triode is connected with the collector electrode of the first triode, the collector electrode of the second triode is used for being connected with the driving power supply, and the emitter electrode of the second triode is grounded;
The base electrode of the third triode is connected with the collector electrode of the second triode, the collector electrode of the third triode is connected with the driving power supply and the switching circuit, and the emitter electrode of the third triode is grounded.
Preferably, in the IC chip protection circuit, a third resistor is connected between the base electrode of the second triode and the collector electrode of the first triode; a fourth resistor is connected between the collector electrode of the second triode and the driving power supply; a fifth resistor is connected between the base electrode of the third triode and the collector electrode of the second triode; and a sixth resistor is connected between the collector electrode of the third triode and the driving power supply.
Preferably, in the IC chip protection circuit, the switching circuit includes a MOS transistor and a seventh resistor;
the grid electrode of the MOS tube is used for connecting the driving power supply and the collector electrode of the third triode;
the source electrode of the MOS tube is used for connecting the IC chip feedback circuit;
And the drain electrode of the MOS tube is used for being connected with the negative electrode of the load end and is connected with the IC chip feedback circuit through the seventh resistor.
Preferably, in the IC chip protection circuit, the IC chip feedback circuit includes an IC chip feedback pin, an eighth resistor, and a diode;
the feedback pin of the IC chip is connected with the source electrode of the MOS tube and is connected with the negative electrode of the load end through a seventh resistor;
One end of the eighth resistor is connected with the feedback pin of the IC chip, and the other end of the eighth resistor is grounded;
and the anode of the diode is connected with the feedback pin of the IC chip, and the cathode of the diode is grounded.
Preferably, in the IC chip protection circuit, the resistance of the seventh resistor is greater than 10 kiloohms.
Preferably, in the IC chip protection circuit, when the load terminal is under-voltage or short-circuited, the voltage regulator, the first triode and the second triode are not turned on, and the base of the third triode receives the electric energy transmitted by the driving power supply and then is turned on, and outputs a low level to the gate of the MOS transistor at the collector; and the grid electrode of the MOS tube is not conducted after receiving the low level, and an output signal of the negative electrode of the load end is transmitted to the feedback pin of the IC chip after being divided by the seventh resistor.
Preferably, in the IC chip protection circuit, the control circuit includes an IC1 op-amp chip, a driving power supply, and a reference voltage;
the first pin of the IC1 operational amplifier chip is connected with the switch circuit;
The second pin of the IC1 operational amplifier chip is connected with the reference voltage;
the third pin of the IC1 operational amplifier chip is connected with the sampling comparison circuit and is grounded through a resistor;
The fourth pin of the IC1 operational amplifier chip is grounded;
And an eighth pin of the IC1 operational amplifier chip is connected with the driving power supply.
Preferably, in the IC chip protection circuit, the load terminal includes an LED lamp.
The invention provides an IC chip protection circuit, which comprises a sampling comparison circuit, a control circuit, a switching circuit and an IC chip feedback circuit; the sampling comparison circuit is used for connecting a load end to acquire a voltage value of the load end, comparing the voltage value with a preset voltage stabilizing value and determining whether the load end is in an under-voltage or short-circuit state; the control circuit is connected with the sampling comparison circuit and is used for generating a voltage limiting instruction to be sent to the switch circuit when the load end is in an under-voltage or short-circuit state; the switch circuit is connected with the IC chip feedback circuit and is used for limiting the voltage transmitted to the IC chip feedback circuit by the load end after receiving the voltage limiting instruction; the IC chip feedback circuit is connected with the load end and is used for feeding back an output signal of the load end to the IC chip. The IC chip protection circuit can reduce the voltage of the feedback signal transmitted to the IC chip by the load end when the load is undervoltage or short-circuited, and avoid damage caused by overlarge voltage of the IC chip.
In order to make the above objects, features and advantages of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the present invention, the drawings that are required for the embodiments will be briefly described, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope of the present invention. Like elements are numbered alike in the various figures.
Fig. 1 is a schematic structural diagram of an IC chip protection circuit according to embodiment 1 of the present invention;
fig. 2 is a schematic circuit diagram of an IC chip protection circuit according to embodiment 2 of the present invention;
fig. 3 is a circuit schematic of an IC chip protection circuit according to embodiment 3 of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.
The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.
The terms "comprises," "comprising," "including," or any other variation thereof, are intended to cover a specific feature, number, step, operation, element, component, or combination of the foregoing, which may be used in various embodiments of the present invention, and are not intended to first exclude the presence of or increase the likelihood of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the invention belong. The terms (such as those defined in commonly used dictionaries) will be interpreted as having a meaning that is the same as the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in connection with the various embodiments of the invention.
Example 1
Fig. 1 is a schematic structural diagram of an IC chip protection circuit according to embodiment 1 of the present invention.
The IC chip protection circuit 100 includes a sampling comparison circuit 110, a control circuit 120, a switching circuit 130, and an IC chip feedback circuit 140;
The sampling comparison circuit 110 is configured to connect to the load terminal 150 to collect a voltage value of the load terminal 150, and compare the voltage value with a preset voltage stabilizing value to determine whether the load terminal 150 is in an under-voltage or short-circuit state;
In the embodiment of the invention, the IC chip is generally applied to the booster circuit, the IC chip is utilized to send out pulse width modulation signals to play a role in limiting power in the booster circuit, and when the IC chip is utilized to adjust output voltage, the current of a load needs to be detected and converted into voltage to be fed back to a feedback pin of the IC chip, so that the power can be accurately limited. In a general boost circuit, the feedback pin of the IC chip is connected to the negative electrode of the load terminal 150 through a resistor and a diode to obtain a feedback signal of the load terminal 150, and the feedback pin may transmit a high voltage to the IC chip when the load is shorted or undervoltage, resulting in damage of the IC chip.
In the embodiment of the present invention, the IC chip protection circuit 100 is mainly used to limit the voltage of the feedback signal of the load terminal 150 under the condition of under-voltage or short circuit, thereby protecting the IC chip. The IC chip protection circuit 100 may be applied to various product devices using IC chips, and is not limited herein. Wherein the load terminal 150 includes an LED lamp. The sampling comparison circuit 110 of the IC chip protection circuit 100 may be connected to the positive and negative ends of the LED lamp, and collect voltages of the positive and negative ends of the LED lamp, that is, a voltage value of the load terminal 150, and then compare the voltage value with a voltage stabilizing value to determine a state of the output of the load terminal 150. When the voltage value is greater than the voltage stabilizing value, the output of the load terminal 150 is in a normal state, when the voltage value is less than the voltage stabilizing value, the output of the load terminal 150 is in an under-voltage state, and when the voltage value is zero, the output of the load terminal 150 is in a short-circuit state.
The control circuit 120 is connected to the sampling comparison circuit 110, and is configured to generate a voltage limiting instruction when the load end 150 is in an under-voltage or short-circuit state, and send the voltage limiting instruction to the switch circuit 130;
In the embodiment of the present invention, the IC chip protection circuit 100 includes a control circuit 120, where the control circuit 120 is connected to the sampling comparison circuit 110, obtains the output state of the load end 150 determined by the sampling comparison circuit 110, and generates a corresponding instruction to send to the switch circuit 130. The corresponding instruction includes a finite voltage instruction, that is, under the condition that the load terminal 150 outputs normally, the control circuit 120 may not generate any instruction, and the switch circuit 130 and the IC chip feedback circuit 140 operate normally, so that the IC chip feedback circuit 140 may directly obtain the output feedback signal from the negative electrode of the load terminal 150 and transmit the feedback signal to the IC chip. And under the condition that the load terminal 150 outputs undervoltage or short circuit, a voltage limiting instruction is generated and sent to the switch circuit 130, so that the switch circuit 130 limits the voltage of the feedback signal transmitted from the negative electrode of the load terminal 150 to the IC chip feedback circuit 140.
The switch circuit 130 is connected to the IC chip feedback circuit 140, and is configured to limit the voltage transmitted from the load terminal 150 to the IC chip feedback circuit 140 after receiving the voltage limiting command;
In the embodiment of the present invention, the switch circuit 130 is provided with a resistor having a very large resistance, for example, a resistor having a resistance greater than 10 kiloohms may be provided, and the resistor is used to divide the voltage with the IC chip feedback circuit 140 when the output of the load terminal 150 is short-circuited or under-voltage, so as to limit the voltage transmitted from the negative electrode of the load terminal 150 to the IC chip feedback circuit 140.
The IC chip feedback circuit 140 is connected to the load terminal 150, and is configured to feedback an output signal of the load terminal 150 to the IC chip.
In the embodiment of the present invention, the feedback circuit 140 of the IC chip is configured to obtain the output signal of the load terminal 150 and feed back the output signal to the IC chip, so that the IC chip controls the boost circuit of the load to modulate the load voltage. The IC chip is provided with a feedback pin, and is connected with the IC chip feedback circuit 140 through the feedback pin to obtain a feedback signal. Wherein, above-mentioned load end includes the LED lamp.
Example 2
Fig. 2 is a circuit schematic of an IC chip protection circuit according to embodiment 2 of the present invention.
The IC chip protection circuit 200 includes a sampling comparison circuit 210, a control circuit 220, a switching circuit 230, and an IC chip feedback circuit 240;
the sampling comparison circuit 210 is configured to connect to the load terminal 250 to collect a voltage value of the load terminal 250, and compare the voltage value with a preset voltage stabilizing value to determine whether the load terminal 250 is in an under-voltage or short-circuit state;
the control circuit 220 is connected to the sampling comparison circuit 210, and is configured to generate a voltage limiting instruction when the load end 250 is in an under-voltage or short-circuit state, and send the voltage limiting instruction to the switch circuit 230;
The switch circuit 230 is connected to the IC chip feedback circuit 240, and is configured to limit the voltage transmitted from the load terminal to the IC chip feedback circuit 240 after receiving the voltage limiting command;
The IC chip feedback circuit 240 is connected to the load terminal, and is configured to feedback an output signal of the load terminal to the IC chip.
In the embodiment of the present invention, the more detailed functional description of each module may refer to the content of the corresponding portion in the foregoing embodiment, which is not described herein.
In the embodiment of the present invention, the sampling comparison circuit 210 includes a first resistor 21, a second resistor 22, a voltage regulator 23, and a first triode 24; one end of the first resistor 21 is connected with the positive electrode of the LED lamp, and the other end of the first resistor is connected with the voltage stabilizing tube 23 and is used for transmitting the collected voltage value of the load end to the voltage stabilizing tube 23; the voltage regulator 23 is connected to the emitter of the first triode 24, and is configured to turn on the voltage regulator 23 and turn on the first triode 24 when the voltage value is greater than the voltage regulation value of the voltage regulator 23; the base electrode of the first triode 24 is connected with the second resistor 22, and the other end of the second resistor 22 is connected with the negative electrode of the load end; the collector of the first triode 24 is connected to the control circuit 220, and is used for outputting a driving voltage to the control circuit 220 when the first triode 24 is turned on.
In the embodiment of the present invention, the control circuit 220 includes a second triode 25, a third triode 26 and a driving power supply 27; the base electrode of the second triode 25 is used for being connected with the collector electrode of the first triode 24, the collector electrode of the second triode 25 is used for being connected with the driving power supply 27, and the emitter electrode of the second triode 25 is used for being grounded; the base electrode of the third triode 26 is connected to the collector electrode of the second triode 25, the collector electrode of the third triode 26 is connected to the driving power supply 27 and the switching circuit 230, and the emitter electrode of the third triode 26 is grounded.
In the embodiment of the present invention, a third resistor 28 is connected between the base electrode of the second triode 25 and the collector electrode of the first triode 24; a fourth resistor 29 is connected between the collector of the second triode 25 and the driving power supply 27; a fifth resistor 30 is connected between the base electrode of the third triode 26 and the collector electrode of the second triode 25; a sixth resistor 31 is connected between the collector of the third triode 26 and the driving power supply 27.
In the embodiment of the present invention, the switch circuit 230 includes a MOS transistor 32 and a seventh resistor 33; the gate of the MOS transistor 32 is connected to the driving power supply 27 and the collector of the third triode 26; the source electrode of the MOS tube 32 is used for connecting with the IC chip feedback circuit 240; the drain of the MOS transistor 32 is connected to the negative electrode of the load end, and is connected to the IC chip feedback circuit 240 through the seventh resistor 33. Wherein the resistance of the seventh resistor 33 is larger than 10 kohms.
In the embodiment of the present invention, the IC chip feedback circuit 240 includes an IC chip feedback pin 34, an eighth resistor 35, and a diode 36; the IC chip feedback pin 34 is configured to connect to the source of the MOS transistor 32, and connect to the negative electrode of the load terminal through a seventh resistor 33; one end of the eighth resistor 35 is used for connecting with the feedback pin 34 of the IC chip, and the other end is used for grounding; the anode of the diode 36 is used for connecting to the IC chip feedback pin 34, and the cathode is used for grounding.
In the IC chip protection circuit 200 of the embodiment of the present invention, when the load end works normally, the voltage value between the positive and negative electrodes is greater than the voltage stabilizing value of the voltage stabilizing tube 23, and at this time, the voltage stabilizing tube 23 and the first triode 24 are turned on. When the first transistor 24 is turned on, the collector of the first transistor 24 outputs a voltage, and the second transistor 25 is driven through the third resistor 28, so that the second transistor 25 is turned on, and the collector of the second transistor 25 outputs a low level. The base of the third transistor 26 is connected to the collector of the second transistor 25, so that the driving voltage of the base of the third transistor 26 is low, and the third transistor 26 cannot be turned on. When the third transistor 26 cannot be turned on, the driving power supply 27 drives the gate of the MOS transistor 32 through the sixth resistor 31, so that the source and the drain of the MOS transistor 32 are connected. The resistance between the source and drain of the MOS transistor 32 is very low in the case of communication, and can be ignored, so that the negative electrode of the load terminal can be approximately considered to be directly connected to the IC chip feedback pin 34, and the short signal output by the load terminal is fed back to the IC chip through the IC chip feedback pin 34.
In the IC chip protection circuit 200 of the embodiment of the present invention, when the load terminal is under voltage or short-circuited, the voltage value between the cathodes thereof is smaller than the voltage stabilizing value of the voltage stabilizing tube 23, and at this time, the voltage stabilizing tube 23 and the first triode 24 are not conducted, and the second triode 25 is also not conducted. And the driving power supply 27 drives the third triode 26 through the fourth resistor 29 and the fifth resistor 30 to conduct the third triode 26. The collector of the third triode 26 after being turned on outputs a low level, so that the MOS tube 32 connected with the collector cannot be turned on, therefore, the negative electrode of the load end is connected to the IC chip feedback pin 34 after passing through the seventh resistor 33, and most of the voltage of the output signal is consumed because the resistance value of the seventh resistor 33 is above 10 kiloohms, so that the voltage transmitted to the IC chip feedback pin 34 is reduced, and the IC chip is protected. Wherein, above-mentioned load end includes the LED lamp.
The IC chip protection circuit 200 of the embodiment of the invention adopts simple devices such as a voltage stabilizing tube, a triode, a MOS tube, a resistor and the like to form an undervoltage and short-circuit protection circuit of the constant current output circuit, has simple circuit, convenient debugging and strong practicability, and can realize miniaturization of a PCB. The control is realized by adopting switching devices such as a triode, a MOS tube and the like, the switching speed is high, the protection speed is high, and the reliability is high.
Example 3
Fig. 3 is a circuit schematic of an IC chip protection circuit according to embodiment 3 of the present invention.
The IC chip protection circuit 300 includes a sampling comparison circuit 310, a control circuit 320, a switching circuit 330, and an IC chip feedback circuit 340;
The sampling comparison circuit 310 is connected to a load end, and is configured to collect a voltage value of the load end, compare the voltage value with a preset voltage stabilizing value, and determine that an output of the load end is in an under-voltage or short-circuit state;
The control circuit 320 is connected to the sampling comparison circuit 310, and is configured to generate a voltage limiting instruction and send the voltage limiting instruction to the switch circuit 330 when the output of the load end is in an under-voltage or short-circuit state;
the switch circuit 330 is connected to the IC chip feedback circuit 340, and is configured to limit the voltage transmitted from the load terminal to the IC chip feedback circuit 340 after receiving the voltage limiting command;
the IC chip feedback circuit 340 is connected to the load terminal, and is configured to feedback an output signal of the load terminal to the IC chip.
In the embodiment of the present invention, the more detailed functional description of each module may refer to the content of the corresponding portion in the foregoing embodiment, which is not described herein.
In the embodiment of the present invention, the control circuit 320 includes an IC1 operational amplifier chip 321, a driving power supply 322, and a reference voltage 323; a first pin of the IC1 op-amp chip 321 is used for connecting the switch circuit; the second pin of the IC1 op-amp chip 321 is used for connecting the reference voltage 323; the third pin of the IC1 op-amp chip 321 is used for connecting to the sampling comparator circuit and is grounded through a resistor; the fourth pin of the IC1 op-amp chip 321 is used for grounding; the eighth pin of the IC1 op-amp 321 is used for connecting to the driving power supply 322.
In the embodiment of the invention, when the load end is under voltage or short-circuited, the voltage value between the cathodes thereof is smaller than the voltage stabilizing value of the voltage stabilizing tube, so that the voltage stabilizing tube and the triode in the sampling comparison circuit 310 are not conducted, therefore, the positive input end of the third pin of the IC1 operational amplifier chip 321 is grounded to be low level through a resistor, the second pin is connected with the reference voltage 323, the voltage of the second pin is larger than that of the third pin, and therefore, the output of the IC1 operational amplifier chip 321 is zero, the MOS tube of the switching circuit 330 cannot be conducted, and the cathodes of the load end are connected with the feedback pin of the IC chip through a large resistor, thereby protecting the IC chip. Wherein, above-mentioned load end includes the LED lamp.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (7)
1. The IC chip protection circuit is characterized by comprising a sampling comparison circuit, a control circuit, a switching circuit and an IC chip feedback circuit;
the sampling comparison circuit is used for connecting a load end to acquire a voltage value of the load end, comparing the voltage value with a preset voltage stabilizing value and determining whether the load end is in an under-voltage or short-circuit state;
The control circuit is connected with the sampling comparison circuit and is used for generating a voltage limiting instruction to be sent to the switch circuit when the load end is in an under-voltage or short-circuit state;
the switch circuit is connected with the IC chip feedback circuit and is used for limiting the voltage transmitted to the IC chip feedback circuit by the load end after receiving the voltage limiting instruction;
The IC chip feedback circuit is connected with the load end and is used for feeding back an output signal of the load end to the IC chip;
The sampling comparison circuit comprises a first resistor, a second resistor, a voltage stabilizing tube and a first triode; one end of the first resistor is connected with the positive electrode of the load end, and the other end of the first resistor is connected with the voltage stabilizing tube and is used for transmitting the collected voltage value of the load end to the voltage stabilizing tube; the voltage stabilizing tube is connected with the emitter of the first triode and is used for conducting the voltage stabilizing tube and the first triode when the voltage value is larger than the voltage stabilizing value of the voltage stabilizing tube; the base electrode of the first triode is connected with the second resistor, and the other end of the second resistor is connected with the negative electrode of the load end; the collector electrode of the first triode is connected with the control circuit and is used for outputting a driving voltage to the control circuit when the first triode is conducted;
The control circuit comprises a second triode, a third triode and a driving power supply; the base electrode of the second triode is connected with the collector electrode of the first triode, the collector electrode of the second triode is used for being connected with the driving power supply, and the emitter electrode of the second triode is grounded; the base electrode of the third triode is connected with the collector electrode of the second triode, the collector electrode of the third triode is connected with the driving power supply and the switching circuit, and the emitter electrode of the third triode is grounded;
The switching circuit comprises an MOS tube and a seventh resistor; the grid electrode of the MOS tube is used for connecting the driving power supply and the collector electrode of the third triode; the source electrode of the MOS tube is used for connecting the IC chip feedback circuit; the drain electrode of the MOS tube is used for connecting with the negative electrode of the load end and is connected with the IC chip feedback circuit through the seventh resistor;
And a third resistor is connected between the base electrode of the second triode and the collector electrode of the first triode.
2. The IC chip protection circuit of claim 1, wherein a fourth resistor is connected between the collector of the second transistor and the driving power supply; a fifth resistor is connected between the base electrode of the third triode and the collector electrode of the second triode; and a sixth resistor is connected between the collector electrode of the third triode and the driving power supply.
3. The IC chip protection circuit of claim 1, wherein the IC chip feedback circuit comprises an IC chip feedback pin, an eighth resistor, and a diode;
the feedback pin of the IC chip is connected with the source electrode of the MOS tube and is connected with the negative electrode of the load end through a seventh resistor;
One end of the eighth resistor is connected with the feedback pin of the IC chip, and the other end of the eighth resistor is grounded;
and the anode of the diode is connected with the feedback pin of the IC chip, and the cathode of the diode is grounded.
4. The IC chip protection circuit of claim 3, wherein the seventh resistor has a resistance value greater than 10 kiloohms.
5. The IC chip protection circuit of claim 3, wherein the voltage regulator, the first transistor, and the second transistor are turned off when the load terminal is under-voltage or short-circuited, and a base of the third transistor receives the electric energy transmitted by the driving power supply, is turned on, and outputs a low level to a gate of the MOS transistor at a collector; and the grid electrode of the MOS tube is not conducted after receiving the low level, and an output signal of the negative electrode of the load end is transmitted to the feedback pin of the IC chip after being divided by the seventh resistor.
6. The IC chip protection circuit according to claim 1, wherein the control circuit includes an IC1 op-amp chip, a driving power supply, and a reference voltage;
the first pin of the IC1 operational amplifier chip is connected with the switch circuit;
The second pin of the IC1 operational amplifier chip is connected with the reference voltage;
the third pin of the IC1 operational amplifier chip is connected with the sampling comparison circuit and is grounded through a resistor;
The fourth pin of the IC1 operational amplifier chip is grounded;
And an eighth pin of the IC1 operational amplifier chip is connected with the driving power supply.
7. The IC chip protection circuit according to any one of claims 1 to 6, wherein the load side includes an LED lamp.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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CN201910385723.0A CN110265975B (en) | 2019-05-09 | 2019-05-09 | IC chip protection circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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CN201910385723.0A CN110265975B (en) | 2019-05-09 | 2019-05-09 | IC chip protection circuit |
Publications (2)
Publication Number | Publication Date |
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CN110265975A CN110265975A (en) | 2019-09-20 |
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CN111405705B (en) * | 2020-03-25 | 2023-06-27 | 赛尔富电子有限公司 | Dimming LED controller and output short-circuit protection method |
CN113359672A (en) * | 2021-06-17 | 2021-09-07 | 南方电网数字电网研究院有限公司 | Electric power system chip protection control circuit board and secondary equipment in electric power system |
CN116978904B (en) * | 2023-07-27 | 2024-02-23 | 屹晶微电子(台州)有限公司 | Power supply voltage stabilizing circuit and integrated chip |
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CN101959352A (en) * | 2010-10-15 | 2011-01-26 | 上海小糸车灯有限公司 | LED driving circuit with LED short-circuit protection |
CN103326325A (en) * | 2013-06-05 | 2013-09-25 | 广州凯盛电子科技有限公司 | Short-circuit and low-voltage protective circuit of output of switching power source |
CN103647447A (en) * | 2013-12-25 | 2014-03-19 | 青岛乾程电子科技有限公司 | Power supply device of communication module of electric energy meter |
CN209571817U (en) * | 2019-05-09 | 2019-11-01 | 四川莱福德科技有限公司 | IC chip protects circuit |
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CN101931317A (en) * | 2009-06-24 | 2010-12-29 | 海洋王照明科技股份有限公司 | Power supply start control circuit and power supply |
CN101959352A (en) * | 2010-10-15 | 2011-01-26 | 上海小糸车灯有限公司 | LED driving circuit with LED short-circuit protection |
CN103326325A (en) * | 2013-06-05 | 2013-09-25 | 广州凯盛电子科技有限公司 | Short-circuit and low-voltage protective circuit of output of switching power source |
CN103647447A (en) * | 2013-12-25 | 2014-03-19 | 青岛乾程电子科技有限公司 | Power supply device of communication module of electric energy meter |
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