CN110021923B - Surge protection circuit and electronic equipment - Google Patents
Surge protection circuit and electronic equipment Download PDFInfo
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- CN110021923B CN110021923B CN201910303357.XA CN201910303357A CN110021923B CN 110021923 B CN110021923 B CN 110021923B CN 201910303357 A CN201910303357 A CN 201910303357A CN 110021923 B CN110021923 B CN 110021923B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
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Abstract
The application provides a surge protection circuit and electronic equipment, in the surge protection circuit that this application provided, when surge voltage appears at the input, the input voltage of input output is received to the voltage reduction unit to carry out the voltage drop to the input voltage who receives, output voltage. When the output voltage output by the voltage reduction unit is greater than the threshold voltage in the detection unit, the detection unit generates a first conduction voltage, so that the surge discharge unit receiving the first conduction voltage discharges the input voltage. The output voltage output by the voltage reduction unit is less than or equal to the input voltage. The surge protection circuit has the advantages that the surge voltage is discharged in the mode, on the basis of ensuring the direct current withstand voltage of the surge protection circuit, the input voltage received by the surge pipe in the surge discharge unit is reduced when the surge discharge unit discharges energy, and the problem that the surge pipe is easily burnt due to overlarge power consumption on the surge pipe caused by overhigh input voltage received in the surge discharge unit is solved.
Description
Technical Field
The invention relates to the technical field of integrated circuits, in particular to a surge protection circuit and electronic equipment.
Background
Circuits often produce high operating overvoltages in the event of lightning strikes and when inductive or large loads are switched on, off, such transient overvoltages (or overcurrents) being referred to as surge voltages (or surge currents). The surge voltage (or surge current) is a kind of transient disturbance, which may cause damage to computers and various hardware devices, damage to power supply devices, unstable operation of electronic devices, and accelerated aging.
In order to ensure safe and reliable operation of various hardware devices and electronic devices and prolong the service life of the hardware devices and the electronic devices, surge protection circuits need to be additionally arranged at ports of the hardware devices and the electronic devices to timely release surge voltage, so that the hardware devices and the electronic devices are prevented from being damaged by the surge voltage, and the safe and reliable operation of the hardware devices and the electronic devices is ensured.
In the existing surge protection circuit, ports of various hardware devices and electronic devices applying the surge protection circuit usually need to be provided with higher direct-current voltage withstand voltage, so that the ports are not easily damaged by the surge voltage. For the surge protection circuit, when ports of various hardware devices and electronic devices are provided with high direct-current voltage withstand voltage values, the surge protection circuit also needs to bear corresponding direct-current voltage when the surge protection circuit releases the surge voltage. However, in the past, when the surge tube in the surge protection circuit discharges the surge voltage, the discharge capability of the surge tube is not saturated, and the thermal breakdown has already occurred. Specifically, the existing surge tube is used for discharging energy at the input end after the surge tube is opened, wherein the direct-current voltage at the input end is greater than the starting voltage of the surge tube. When the surge tube discharges energy, the voltage at the input end of the surge tube is higher, the power consumption on the surge tube is higher, and the surge tube is easily burnt.
Disclosure of Invention
Based on the defects of the prior art, the invention provides a surge protection circuit and electronic equipment, so as to reduce the power consumption of a surge pipe in the surge protection circuit and reduce the burning probability of the surge pipe.
In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:
the invention discloses a surge protection circuit in a first aspect, comprising:
the voltage reduction unit receives input voltage output by an input end, reduces the received input voltage and outputs output voltage; wherein the output voltage is less than or equal to the input voltage;
the detection unit is connected with the voltage reduction unit and receives the output voltage output by the voltage reduction unit; when the output voltage is larger than the threshold voltage, the detection unit outputs a first breakover voltage;
the surge discharging unit is connected with the detection unit and receives the first breakover voltage output by the detection unit; and the surge discharge unit discharges the input voltage output by the input end according to the first breakover voltage.
Optionally, in the surge protection circuit, the voltage dropping unit includes: a capacitor and a first voltage stabilizing circuit;
the upper plate of the capacitor is connected with the input end and the common end of the first voltage stabilizing circuit, and the lower plate of the capacitor is connected with one end of the first voltage stabilizing circuit, which is far away from the input end;
the common end of the upper plate of the capacitor and the first voltage stabilizing circuit is used as an input port of the voltage reduction unit to receive the input voltage;
and the common end of the lower polar plate of the capacitor and the first voltage stabilizing circuit is used as an output port of the voltage reduction unit to output the output voltage.
Optionally, in the surge protection circuit, the first voltage regulator circuit includes: at least one first zener diode; the first voltage stabilizing diodes are connected in series.
Optionally, in the surge protection circuit, a series connection mode at least including two first zener diodes among the series connections of the first zener diodes is as follows: the cathode of the first voltage stabilizing diode is connected with the cathode of the adjacent first voltage stabilizing diode.
Optionally, in the surge protection circuit, the detection unit includes: a second voltage stabilizing circuit and a resistor;
the input end of the second voltage stabilizing circuit receives the output voltage, and the output end of the second voltage stabilizing circuit is grounded through the resistor;
one end of the resistor far away from the ground is used for outputting the first breakover voltage.
Optionally, in the surge protection circuit, the second voltage stabilizing circuit includes: at least one second zener diode; the second voltage stabilizing diodes are connected in series.
Optionally, in the surge protection circuit, a series connection mode at least including a series connection mode between two second zener diodes in a series connection between a plurality of second zener diodes is as follows: and the cathode of the second voltage stabilizing diode is connected with the cathode of the adjacent second voltage stabilizing diode.
Optionally, in the surge protection circuit, the surge bleeding unit includes:
the second end of the switch tube receives the input voltage, the control end of the switch tube is used for receiving the first breakover voltage, and the first end of the switch tube is grounded.
Optionally, in the surge protection circuit described above, the switching tube is a transistor.
A second aspect of the present invention discloses an electronic device, comprising:
the working circuit is connected with the input end and used for receiving input voltage, and the input voltage is used for driving the working circuit to work;
a surge protection circuit as claimed in any preceding claim.
According to the technical scheme, in the surge protection circuit provided by the invention, when surge voltage appears at the input end, the voltage reduction unit receives the input voltage output by the input end, reduces the voltage of the received input voltage and outputs the output voltage. When the output voltage output by the voltage reduction unit is greater than the threshold voltage in the detection unit, the detection unit generates a first conduction voltage, so that the surge discharge unit receiving the first conduction voltage discharges the input voltage. The output voltage output by the voltage reduction unit is less than or equal to the input voltage. The surge discharge unit is discharged by the generation of the first breakover voltage, and on the basis of ensuring the direct current withstand voltage of the surge protection circuit, the input voltage received by the surge pipe in the surge discharge unit is reduced when the surge discharge unit discharges energy, so that the problem that the surge pipe is easily burnt due to the fact that the power consumption on the surge pipe is too large due to the fact that the input voltage received in the surge discharge unit is too high is solved, and the probability that the surge pipe is burnt in the surge protection circuit is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a circuit diagram of a prior art surge protection circuit;
fig. 2 is a diagram showing a simulation result of a conventional surge protection circuit;
fig. 3 is a structural diagram of a surge protection circuit disclosed in an embodiment of the present application;
fig. 4 is a circuit diagram of a surge protection circuit disclosed in an embodiment of the present application;
FIG. 5 is a circuit diagram of a first voltage regulator circuit according to an embodiment of the disclosure;
fig. 6 is a diagram of a simulation result of a surge protection circuit disclosed in an embodiment of the present application;
fig. 7 is a comparison diagram of simulation results of a surge protection circuit disclosed in the embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the prior art, a surge protection circuit applied in an integrated circuit, as shown in fig. 1, includes a voltage regulator circuit 101, a resistor R1, and a switching tube M1. The input end of the voltage stabilizing circuit 101 receives the input voltage Vin output by the input end, and the output end of the voltage stabilizing circuit 101 is grounded to GND through a resistor R1. The drain of the switching tube M1 receives the input voltage Vin output from the input terminal, the source of the switching tube M1 is grounded, and the gate of the switching tube M1 is connected to the output port of the regulator circuit 101. The voltage stabilizing circuit 101 includes a plurality of first zener diodes Z1, and the plurality of first zener diodes Z1 are connected in series. Specifically, the plurality of first zener diodes Z1 are connected in series such that the cathode of a first zener diode Z1 is connected to the cathode of an adjacent first zener diode Z1. The switch transistor M1 is typically an NMOS transistor.
When a surge voltage occurs at the input terminal, that is, when the input voltage Vin output from the input terminal is an instantaneous overvoltage greater than the clamp voltage of the first voltage stabilizing circuit 101. The first zener diode Z1 in the first stabilizing circuit 101 is breakdown-conducted to output a first conduction voltage V1. The gate of the switching tube M1 receives the first on voltage V1 output by the first voltage regulator 101, and when the first on voltage V1 is greater than the turn-on voltage of the switching tube M1, the switching tube M1 is turned on to drain the surge voltage at the input end.
Further, the output voltage Vin at the input terminal is clamped by the clamping voltage of the first regulator 101, and a small voltage is added to the first regulator 101 to cause a large leakage. When the first regulator 101 generates a leakage, the leakage generates a voltage drop through the resistor R1, and the voltage drop across the resistor R1 is equal to the gate-source voltage of the switch M1. If the switch tube is an NMOS transistor, according to the characteristics of the NMOS transistor, the greater the gate-source voltage of the NMOS transistor, the stronger the ability of the NMOS transistor to discharge current.
It should be noted that, in order to fully utilize the ability of the NMOS transistor to drain current, the gate-source voltage of the NMOS transistor should be given a reasonable value, and the following factors should be fully considered: on one hand, the drain capacity of the NMOS transistor is increased firstly and then tends to be saturated along with the increase of the grid-source voltage, on the other hand, the thickness of the grid oxide of the NMOS transistor determines that the grid-source voltage cannot be too large, otherwise, the grid oxide breaks down.
However, in the actual use process, when the input voltage Vin output by the input terminal is too high, the voltage applied to the drain and source terminals of the NMOS transistor will generate a large power loss, and often when the current-sinking capability of the NMOS transistor does not reach the maximum value, the NMOS transistor will have thermal damage.
The following explains how the switching tube in the surge protection circuit in fig. 1 is susceptible to thermal damage, with reference to fig. 2, based on simulation results of the surge protection circuit in fig. 1. When the surge voltage appearing at the input end is 90V, the clamping voltage of the first voltage stabilizing circuit to the input voltage is 29.4442V, the voltage of a tap of a first voltage stabilizing diode in the first voltage stabilizing circuit is 20.471V, the peak current when the surge voltage is discharged by the switching tube is 29.667a, and the maximum power loss of the switching tube is P ═ UI ═ 29.442V × 29.667a ≈ 873.46W.
From the above values, when the switching tube discharges surge voltage, the maximum power loss of the switching tube is very large, and the thermal damage of the switching tube is easily caused by the large-value power damage.
The switching tube is a surge tube in the surge protection circuit and is used for discharging surge energy.
In addition, a high dc voltage withstand voltage is generally required to be provided to a port of various hardware devices and electronic devices to which the surge protection circuit is applied, so that the port is not easily damaged by the surge voltage. For the surge protection circuit itself, when ports of various hardware devices and electronic devices have a high dc voltage withstand voltage, the surge protection circuit also needs to bear a corresponding dc voltage when the surge voltage is released.
The surge protection circuit is required to bear high direct-current voltage withstand voltage and release surge voltage generated at the input end. In the past, when the surge tube is used for releasing energy, if the surge voltage generated at the input end is higher, the power consumption applied to the surge tube is very large, and when the releasing capacity of the surge tube is not saturated, the surge tube is burnt.
The embodiment of the application provides a surge protection circuit to solve the problems of the existing surge protection circuit, so that the power loss born by the surge protection circuit is reduced, and the burning probability of a surge tube in the surge protection circuit is further reduced.
Referring to fig. 3, a surge protection circuit disclosed in the embodiment of the present application includes:
the voltage reducing unit 301, the voltage reducing unit 301 receives the input voltage output by the input terminal, reduces the received input voltage, and outputs an output voltage.
Wherein the output voltage is less than or equal to the input voltage.
The input terminal is a port through which the surge protection circuit receives the input voltage, and is also a port through which the operating circuit connected to the surge protection circuit receives the input voltage.
It should be noted that the output voltage output by the voltage reduction unit 301 is to reduce the surge clamp voltage at the input terminal of the surge protection circuit, so that the surge protection circuit can discharge the voltage at the time of surge at the input terminal when the surge voltage with low energy appears at the input terminal.
Optionally, referring to fig. 4, in another embodiment of the present application, an implementation of the voltage reduction unit 401 includes:
a capacitor C and a first stabilizing circuit 4011. An upper plate of the capacitor C is connected to the input end and a common end of the first voltage stabilizing circuit 4011, and a lower plate of the capacitor C is connected to one end of the first voltage stabilizing circuit 4011 far from the input end.
The common terminal of the upper plate of the capacitor C and the first voltage stabilizing circuit 4011 serves as an input port of the voltage reducing unit 401, and receives the input voltage Vin;
the common terminal of the lower plate of the capacitor C and the first voltage stabilizing circuit 4011 serves as an output port of the voltage reducing unit 401, and outputs the output voltage Vout.
It should be noted that the first voltage stabilizing circuit 4011 is in the surge protection circuit, and is configured to set a value of the input voltage Vin received by the surge protection circuit, where a surge tube in the circuit is turned on to discharge surge energy. However, the first stabilizing circuit 4011 is only a part of the determination circuit in the surge protection circuit that determines when the input voltage Vin is, the surge tube turns on the leakage energy. In the surge protection circuit, there are other voltage stabilizing circuits or circuits with other properties, and when the input voltage Vin of the input terminal received by the surge protection circuit is determined to be large by the series or parallel connection with the first voltage stabilizing circuit 4011, the surge protection circuit performs surge discharge.
It should be further noted that, the voltage reduction function of the voltage reduction unit 401 is realized by the cooperation of the capacitor C and the first voltage stabilizing circuit 4011 in the case that the upper plate of the capacitor C is connected to the common terminal of the input terminal and the lower plate of the capacitor C is connected to the end of the first voltage stabilizing circuit 4011 far away from the input terminal. Specifically, the upper plate and the lower plate of the capacitor C are connected in parallel to two ends of the first voltage stabilizing circuit 4011, and when a surge voltage appears at the input end, i.e., at the input port of the voltage reducing unit 401, the received input voltage Vin is the surge voltage. The capacitor C couples the surge voltage at the input terminal to a first zener diode tap connected to the lower plate of the capacitor C in the first voltage stabilizing circuit 4011 through the capacitor C according to its own characteristics.
The upper plate of the capacitor C receives the surge voltage output by the input end, and discharges the received surge voltage through the lower plate of the capacitor C, and the output voltage Vout output by the lower plate of the capacitor C at the moment is less than or equal to the surge voltage received by the upper plate of the capacitor C.
The output voltage of the lower plate of the capacitor C is the output voltage Vout output by the voltage step-down unit 401.
During the coupling of the capacitor C to the input terminal and the first stabilizing circuit 4011. The first voltage stabilizing circuit 4011 connected in parallel to the capacitor C is equivalent to a short-circuited by the capacitor C, and the short-circuited first voltage stabilizing circuit 4011 does not clamp the surge protection circuit. That is, the first voltage stabilizing circuit 4011 that is short-circuited lowers the clamp value of the surge protection circuit to the input voltage Vin. At this time, if the output voltage Vout output by the capacitor C is larger than the clamp voltage of the surge protection circuit after the first voltage stabilizing circuit 4011 is short-circuited, the output voltage Vout turns on a surge tube in the surge protection circuit, thereby discharging surge energy.
It should be noted that when the input voltage Vin received by the voltage-reducing unit 401 exceeds the voltage-resistant value of the capacitor C in the voltage-reducing unit 401, that is, when the surge voltage appearing at the input terminal is very large and far exceeds the voltage-resistant value of the capacitor C, the capacitor C may be exposed to burning. If the capacitor C cannot withstand such a large surge voltage, the burned capacitor C no longer has a coupling function, and cannot be coupled to the input terminal and the first voltage stabilizing circuit 4011. At this time, the capacitor C cannot be matched with the first voltage stabilizing circuit 4011 in the surge protection circuit, so that the voltage reduction function of the voltage reduction unit 401 is realized.
The capacitor C loses the effect of reducing the surge clamping voltage at the input end in the surge protection circuit, at this time, the surge voltage breaks down the first voltage stabilizing circuit 4011 and other voltage stabilizing circuits in the surge protection circuit to generate a second conduction voltage, and the second conduction voltage enables a surge tube in the surge discharging unit to be opened to discharge surge current.
It should be noted that, in the first voltage stabilizing circuit 4011 and other voltage stabilizing circuits in the surge protection circuit, which are broken down by the surge voltage, the clamp value of the input voltage at the input end is the sum of the regulated voltage value of the first voltage stabilizing circuit and the regulated voltage values of the other voltage stabilizing circuits, and is much larger than the clamp value of the input voltage at the input end before the capacitor C is not burned.
So, if do not have the mutual supporting of electric capacity C and first voltage stabilizing circuit 401 among the surge protection circuit, realize the step-down to input voltage for the input voltage of input carries out the earial drainage to the surge voltage that the input appears when a lower clamp value, and the power loss that the surge pipe among the surge protection circuit switched on can be very big, and the probability that the surge pipe burns out is very high.
It should be noted that, in the present embodiment, the capacitance of the capacitor C generally takes a larger value.
Optionally, in another embodiment of the present application, the first voltage stabilizing circuit includes: at least one first zener diode; the plurality of first voltage stabilizing diodes are connected in series.
It should be noted that the first voltage stabilizing circuit is composed of at least one first voltage stabilizing diode. When the number of the first voltage stabilizing diodes of the first voltage stabilizing circuit exceeds one, the connection mode among the first voltage stabilizing diodes is as follows: are connected in series. The first zener diode may be connected in series, where an anode of the first zener diode is connected to a cathode of the adjacent first zener diode, or the cathode of the first zener diode is connected to an anode of the adjacent first zener diode. Of course, the anode of the first zener diode may be connected to the anode of the adjacent first zener diode, and more specifically, the cathode of the first zener diode may be connected to the cathode of the adjacent first zener diode. The specific serial connection mode is determined according to a clamping voltage value required by a user for the first voltage stabilizing circuit.
Alternatively, in another embodiment of the present application, referring to fig. 5, in the series connection among the plurality of first zener diodes Z1, the series connection at least including between two first zener diodes Z1 is: the cathode of a first zener diode Z1 is connected to the cathode of an adjacent first zener diode Z1.
The detection unit 302 is connected with the voltage reduction unit 301, and the detection unit 302 receives the output voltage output by the voltage reduction unit 301; when the output voltage is greater than the threshold voltage, the detecting unit 302 outputs a first turn-on voltage.
The threshold voltages of the detection cells are: the surge protection circuit is provided with clamping voltages of other voltage stabilizing circuits except the first voltage stabilizing circuit. Wherein the threshold voltage is less than the clamping voltage of the surge protection circuit.
Optionally, referring to fig. 4, in another embodiment of the present application, an implementation of the detecting unit 402 includes:
a second voltage stabilizing circuit 4021 and a resistor R.
The input end of the second voltage stabilizing circuit 4021 receives the output voltage Vout, the output end of the second voltage stabilizing circuit 4021 is grounded GND through a resistor R, and one end of the resistor R away from the GND is used for outputting a first on voltage V1.
Note that the threshold voltage in the detection unit 402 is a clamp voltage of the second voltage stabilizing circuit 4021. When a surge voltage appears at the input terminal, that is, when the input voltage Vin is a surge voltage. The output voltage Vout output by the voltage step-down unit 401 is also a surge voltage, and if the output voltage Vout is greater than the clamp voltage of the second voltage stabilizing circuit 4021, the second voltage stabilizing circuit 4021 is broken down and turned on, generating a first on voltage V1.
Optionally, in another embodiment of the present application, the second voltage stabilizing circuit includes: at least one second zener diode; the plurality of second voltage stabilizing diodes are connected in series.
It should be noted that the second voltage stabilizing circuit is composed of at least one second voltage stabilizing diode. When the number of the second voltage stabilizing diodes in the second voltage stabilizing circuit exceeds one, the connection mode among the second voltage stabilizing diodes is as follows: are connected in series. The second zener diode may be connected in series, where an anode of the second zener diode is connected to a cathode of the adjacent second zener diode, or a cathode of the second zener diode is connected to an anode of the adjacent second zener diode. Of course, the anode of the second zener diode may be connected to the anode of the adjacent second zener diode, and more specifically, the cathode of the second zener diode may be connected to the cathode of the adjacent second zener diode. The specific serial connection mode is determined according to a clamping voltage value required by a user for the second voltage stabilizing circuit.
Optionally, in another embodiment of the present application, referring also to fig. 4, in the series connection of Z2 among the plurality of second zener diodes, the series connection at least including between two second zener diodes Z2 is: the cathode of the second zener diode Z2 is connected to the cathode of the adjacent second zener diode Z2.
The surge discharging unit 303 is connected with the detection unit 302, and the surge discharging unit 303 receives the first breakover voltage output by the detection unit 302; the surge bleeding unit 303 bleeds off the input voltage output from the input terminal according to the first on-voltage.
The larger the first on-voltage is, the stronger the surge relief unit has a capability of relieving the input voltage.
Optionally, referring also to fig. 4, in another embodiment of the present application, the surge bleed-off unit 403 includes:
the second end of the switching tube M1 receives the input voltage Vin, the control end of the switching tube M1 is configured to receive the first on-voltage V, and the first end of the switching tube M1 is grounded to GND.
When the first turn-on voltage V1 received by the control terminal of the switching tube M1 is greater than the turn-on voltage of the switching tube M1, the switching tube M1 is turned on, and a channel is formed between the first terminal and the second terminal of the switching tube M1, so as to drain the input voltage Vin received by the second terminal of the switching tube M1. When the voltage across the gate and the source of the switching tube M1 reaches the turn-on voltage of the switching tube M1, the switching tube M1 is turned on.
The first end of the switching tube M1 is the source of the switching tube, the second end of the switching tube M1 is the drain of the switching tube, and the control end of the switching tube M1 is the gate of the switching tube. In the figure, the end having an arrow is a source, and the end having no arrow is a drain.
Optionally, in another embodiment of the present application, the switching tube in the surge protection circuit may be a transistor, and may also be another type of switching tube having a transistor function.
It should be noted that the switching tube may be an NMOS transistor.
In the surge protection circuit provided by the invention, when surge voltage appears at the input end, the voltage reduction unit receives the input voltage output by the input end, reduces the voltage of the received input voltage and outputs the output voltage. When the output voltage output by the voltage reduction unit is greater than the threshold voltage in the detection unit, the detection unit generates a first conduction voltage, so that the surge discharge unit receiving the first conduction voltage discharges the input voltage. The output voltage output by the voltage reduction unit is less than or equal to the input voltage. The surge discharge unit is discharged by the generation of the first breakover voltage, and on the basis of ensuring the direct current withstand voltage of the surge protection circuit, the input voltage received by the surge pipe in the surge discharge unit is reduced when the surge discharge unit discharges energy, so that the problem that the surge pipe is easily burnt due to the fact that the power consumption on the surge pipe is too large due to the fact that the input voltage received in the surge discharge unit is too high is solved, and the probability that the surge pipe is burnt in the surge protection circuit is reduced.
The following explains the surge protection circuit provided by the present invention further with a simulation diagram of the surge protection circuit provided by the present invention, please refer to fig. 6.
Under the condition that the surge voltage appearing at the input end is 90V, the input voltage output by the input end is capacitively coupled to one end, far away from the input end, of the first voltage stabilizing circuit due to the addition of the capacitor. At this time, the clamping voltage of the surge protection circuit is 20.967V, and the voltage of the first voltage stabilizing diode tap far away from the input end of the first voltage stabilizing circuit is 20.782V. Due to the self-coupling characteristic of the capacitor, the first zener diode connected in parallel with the capacitor is short-circuited instantaneously, and at this time, the peak current when the switching tube in the surge protection circuit discharges surge voltage is 33.976 a. According to the power calculation formula P ═ UI, it can be known that the maximum power loss of the surge protection circuit at this time is: p ═ UI ═ 20.967V ≈ 33.976a ≈ 712.4W.
Comparing the above data with the data of the surge protection circuit simulation in the prior art of fig. 2, the following conclusion can be drawn: the maximum power loss of the surge protection circuit provided by the invention is 712.4W, which is lower than the maximum power loss 873.46W of the surge protection circuit in the prior art, and the peak current of the surge protection circuit provided by the invention is 33.976A, which is higher than the maximum peak current 29.667A of the surge protection circuit in the prior art.
The following compares the simulation schematic diagram of the surge protection circuit provided by the present invention with the simulation schematic diagram of the surge protection circuit in the prior art, and please refer to fig. 7, which can further embody the advantages of the surge protection circuit provided by the present invention.
As can be seen from the figure, the surge protection circuit provided by the present invention can reduce the conduction loss on the surge tube by reducing the clamping voltage at the input terminal under the same surge voltage condition as the conventional surge protection circuit.
Wherein the first set of data at the top in fig. 7 is compared as follows: the surge current in the surge protection circuit provided by the invention is compared with the magnitude of the surge current in the existing surge protection circuit. It can be known that the value of the surge current discharged by the surge protection circuit provided by the invention is 33.929A, which is greater than the value 29.645A of the surge current discharged by the existing surge protection circuit, and the surge current discharging capability of the surge protection circuit provided by the invention is proved to be stronger.
The second set of data in the middle of fig. 7 is compared: the clamping voltage value of the surge protection circuit provided by the invention is compared with the clamping voltage value of the existing surge protection circuit. It can be seen that the value of the clamping voltage of the surge protection circuit provided by the present invention is 20.949V, which is smaller than the value of the clamping voltage of the conventional surge protection circuit of 29.44V, indicating that the clamping value of the clamping voltage of the surge protection circuit provided by the present invention is low and the conduction loss applied to the surge tube is low when the input voltage is a certain value.
The third set of data below in fig. 7 is compared: the power loss of the surge tube in the surge protection circuit provided by the invention is compared with the power loss of the surge tube in the existing surge protection circuit. It can be seen that the power loss of the surge tube in the surge protection circuit provided by the present invention is 710.979W, which is smaller than the power loss 872.743W of the surge tube in the conventional surge protection circuit.
The embodiment of the application discloses electronic equipment, includes: working circuit and surge protection circuit. The working circuit is connected with the input end and used for receiving input voltage, and the input voltage is used for driving the working circuit to work.
It should be noted that, the specific implementation process of the surge protection circuit is consistent with the implementation principle and the surge protection circuit shown in the above embodiment, and reference may be made to this implementation process, which is not described herein again. In particular implementations, the electronic device may include, but is not limited to, a cell phone, a tablet computer, other Universal Serial Bus (USB) interface devices, and the like.
Those skilled in the art can make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Claims (9)
1. A surge protection circuit, comprising:
the voltage reduction unit receives input voltage output by an input end, reduces the received input voltage and outputs output voltage; wherein the output voltage is less than or equal to the input voltage;
the detection unit is connected with the voltage reduction unit and receives the output voltage output by the voltage reduction unit; when the output voltage is larger than the threshold voltage, the detection unit outputs a first breakover voltage;
the surge discharging unit is connected with the detection unit and receives the first breakover voltage output by the detection unit; the surge discharge unit discharges the input voltage output by the input end according to the first breakover voltage;
wherein, the voltage reduction unit includes: a capacitor and a first voltage stabilizing circuit;
the upper plate of the capacitor is connected with the input end and the common end of the first voltage stabilizing circuit, and the lower plate of the capacitor is connected with one end of the first voltage stabilizing circuit, which is far away from the input end;
the common end of the upper plate of the capacitor and the first voltage stabilizing circuit is used as an input port of the voltage reduction unit to receive the input voltage;
and the common end of the lower polar plate of the capacitor and the first voltage stabilizing circuit is used as an output port of the voltage reduction unit to output the output voltage.
2. The circuit of claim 1, wherein the first voltage regulator circuit comprises: at least one first zener diode; the first voltage stabilizing diodes are connected in series.
3. The circuit of claim 2, wherein the series connection between at least two of the first zener diodes in the series connection between the plurality of first zener diodes is: the cathode of the first voltage stabilizing diode is connected with the cathode of the adjacent first voltage stabilizing diode.
4. The circuit of claim 1, wherein the detection unit comprises: a second voltage stabilizing circuit and a resistor;
the input end of the second voltage stabilizing circuit receives the output voltage, and the output end of the second voltage stabilizing circuit is grounded through the resistor;
one end of the resistor far away from the ground is used for outputting the first breakover voltage.
5. The circuit of claim 4, wherein the second voltage regulation circuit comprises: at least one second zener diode; the second voltage stabilizing diodes are connected in series.
6. The circuit of claim 5, wherein the series connection between at least two of the second zener diodes in the series connection between the plurality of second zener diodes is: and the cathode of the second voltage stabilizing diode is connected with the cathode of the adjacent second voltage stabilizing diode.
7. The circuit of claim 1, wherein the surge bleed-off unit comprises:
the second end of the switch tube receives the input voltage, the control end of the switch tube is used for receiving the first breakover voltage, and the first end of the switch tube is grounded.
8. The circuit of claim 7, wherein the switching tube is a transistor.
9. An electronic device, comprising:
the working circuit is connected with the input end and used for receiving input voltage, and the input voltage is used for driving the working circuit to work;
a surge protection circuit according to any of claims 1 to 8.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910303357.XA CN110021923B (en) | 2019-04-16 | 2019-04-16 | Surge protection circuit and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910303357.XA CN110021923B (en) | 2019-04-16 | 2019-04-16 | Surge protection circuit and electronic equipment |
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| CN110021923A CN110021923A (en) | 2019-07-16 |
| CN110021923B true CN110021923B (en) | 2021-05-11 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111190046B (en) * | 2020-01-15 | 2022-06-24 | 上海剑桥科技股份有限公司 | Surge counter |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6501632B1 (en) * | 1999-08-06 | 2002-12-31 | Sarnoff Corporation | Apparatus for providing high performance electrostatic discharge protection |
| CN103022998A (en) * | 2011-09-22 | 2013-04-03 | 株式会社东芝 | Semiconductor device |
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2019
- 2019-04-16 CN CN201910303357.XA patent/CN110021923B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6501632B1 (en) * | 1999-08-06 | 2002-12-31 | Sarnoff Corporation | Apparatus for providing high performance electrostatic discharge protection |
| CN103022998A (en) * | 2011-09-22 | 2013-04-03 | 株式会社东芝 | Semiconductor device |
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| CN110021923A (en) | 2019-07-16 |
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