CN210351011U - Power protection circuit and power conversion module - Google Patents
Power protection circuit and power conversion module Download PDFInfo
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- CN210351011U CN210351011U CN201921582422.9U CN201921582422U CN210351011U CN 210351011 U CN210351011 U CN 210351011U CN 201921582422 U CN201921582422 U CN 201921582422U CN 210351011 U CN210351011 U CN 210351011U
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Abstract
The embodiment of the utility model provides a power protection circuit, wherein the input end of a secondary protection circuit in the protection circuit is connected with the output end of a primary protection circuit, and the primary protection circuit is connected with a power supply; the primary protection circuit comprises a voltage dependent resistor and a thermistor, wherein the thermistor is connected in series with the anode, and the voltage dependent resistor is connected in series between the anode and the cathode; the secondary protection circuit comprises a surge suppressor, an MOS (metal oxide semiconductor) tube and an input resistor, wherein the drain electrode of the MOS tube is connected to the positive electrode, the source electrode of the MOS tube is connected to the negative electrode, the grid electrode of the MOS tube is connected with the charging end of the surge suppressor, the input end of the surge suppressor is connected to the positive electrode of the power supply, the output end of the surge suppressor is connected to the negative electrode, and the input resistor is connected between the positive electrode and the input end of the surge suppressor. The embodiment of the utility model provides a pair of protection circuit of power can guarantee the normal work of circuit, and the time delay of protection surge influences lessly, can avoid the passive suppression of traditional device, guarantees surge voltage's controllable.
Description
Technical Field
The utility model relates to the technical field of circuits, especially, relate to a power protection circuit and power conversion module.
Background
Electromagnetic compatibility is a design factor that must be considered for reliable operation of the circuit. One common threat in the field of electromagnetic compatibility is lightning surge, which is a phenomenon that electronic equipment is damaged by lightning, and the approach can be divided into direct lightning, so that local instantaneous potential rise is caused to generate impact on the equipment, or high-energy induction lightning surge induces high-voltage invasion equipment through an outdoor transmission line to damage the equipment. The degree of damage of a component in the equipment caused by lightning surge depends on the insulation level and the impact strength of the component; for self-healing devices, the breakdown caused by a lightning surge is temporary and the insulation recovers quickly once the shock has disappeared. Some non-self-recovery insulating media do not immediately interrupt the operation of equipment if only a small current flows after breakdown, and the insulation degree of components and parts gradually decreases along with the increase of the operation time, so that the electrical characteristics become weak, and even the normal operation of a circuit is affected.
In the prior art, a lightning surge protection scheme is mainly to connect a Voltage dependent resistor, a ceramic gas discharge tube and a Voltage Transient Suppressor (TVS) in parallel at a power input end to discharge a surge Voltage. The ceramic gas discharge tube has strong discharge transient overcurrent capacity, the action response of the piezoresistor is quick, no follow current exists, and the combined use of the two lightning surge protection devices is a typical use method of most lightning surge protection at present.
However, since the ceramic gas discharge tube has a certain time delay characteristic, the ceramic gas discharge tube cannot be opened immediately after the start threshold is met, that is, the ceramic gas discharge tube cannot be opened until a certain time elapses after the start threshold is met, so that the ceramic gas discharge tube discharges an excessive voltage, and a discharge action has hysteresis; the ceramic gas discharge tube also has certain follow current characteristics, namely after transient voltage passes, the discharge tube which is originally in a conducting state does not extinguish arcs under the action of a power supply of a protected circuit, and still keeps the conducting state, so that the normal work of a post-stage circuit is influenced. In addition, the interelectrode capacitance of the varistor is large and deteriorates quickly. Although the ceramic gas discharge tube and the piezoresistor are used in combination, the defects of the ceramic gas discharge tube and the piezoresistor can be mutually compensated, the risk of failure of lightning protection surge is increased due to the influence of aging factors, and the controllability is poor.
SUMMERY OF THE UTILITY MODEL
The utility model provides a power protection circuit and power conversion module to solve the higher and poor problem of controllability of protection inefficacy risk of current lightning protection surge circuit.
The embodiment of the utility model provides a power protection circuit, protection circuit includes one-level protection circuit and second grade protection circuit, the input of one-level protection circuit with the output of power is connected, the input of second grade protection circuit with the output of one-level protection circuit is connected;
the primary protection circuit comprises a voltage dependent resistor and a thermistor, the thermistor is connected in series with the anode of the power supply, and the thermistor is connected in series between the anode and the cathode of the power supply;
the secondary protection circuit comprises a surge suppressor and an MOS (metal oxide semiconductor) tube, wherein the drain electrode of the MOS tube is connected to the anode of the power supply, the source electrode of the MOS tube is connected to the cathode of the power supply, the grid electrode of the MOS tube is connected to the charging end of the surge suppressor, the input end of the surge suppressor is connected to the anode of the power supply, and the output end of the surge suppressor is connected to the cathode of the power supply.
Optionally, the protection circuit further includes a common mode inductor; the common mode inductor is connected between the primary protection circuit and the secondary protection circuit; the common mode inductor comprises two windings; and two ends of the second winding of the common-mode inductor are connected in series with the negative electrode.
Optionally, the protection circuit further includes a safety capacitor; the safety capacitor is connected between the common mode inductor and the secondary protection circuit; and two pins of the safety capacitor are respectively connected with the cathode and the anode.
Optionally, the safety capacitor includes a first safety capacitor and a second safety capacitor; the first safety capacitor and the second safety capacitor are connected in series.
Optionally, the primary protection circuit further includes a starting capacitor, and the starting capacitor is connected in parallel with the voltage dependent resistor.
Optionally, the secondary protection circuit further includes two filter capacitors, and the two filter capacitors are connected in parallel with the safety capacitor.
Optionally, the surge suppressor is LTC 4366.
Optionally, the MOS transistor is an N-type MOS transistor.
Optionally, a switching rate control resistor is further included between the charging terminal of the surge suppressor and the gate of the MOS transistor; the switching rate control resistor is used for controlling the switching rate of the MOS tube; and the charging end of the surge suppressor is connected with the negative electrode through a charge absorption capacitor, and the charge absorption capacitor is used for absorbing charges from the MOS transistor gate-to-drain capacitor during overvoltage transient.
The embodiment of the utility model also provides a power conversion module, which comprises a conversion chip and the protection circuit;
the input end of the primary protection circuit is provided with a power interface which is used for being connected with a power supply;
and the output end of the secondary protection circuit is connected with the conversion chip.
Compared with the prior art, the utility model discloses possess following advantage:
the embodiment of the utility model provides a pair of protection circuit of power and contain this protection circuit's power conversion module, established the one-level protection circuit including piezo-resistor and thermistor, and the second grade protection circuit including surge suppressor and MOS pipe, second grade protection circuit's input is connected with one-level protection circuit's output. The voltage dependent resistor is used for providing a discharge channel for surge energy, surge voltage can be discharged to the ground, the thermistor is used for limiting the passing of surge current, the resistance value of the thermistor can be reduced in a short time along with the rise of temperature, the normal work of a circuit is ensured, and the time delay influence of surge protection is small; and the surge suppressor and the MOS tube in the secondary protection circuit are used in a combined mode, and the output of the MOS tube is adjusted through the surge suppressor, so that the secondary protection circuit can make up the possible failure of the piezoresistor due to aging, the protection performance is improved, the passive suppression of the traditional device is avoided, and the controllability of surge voltage is ensured.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic diagram of a power protection circuit according to an embodiment of the present invention;
fig. 2 is a schematic diagram of another power protection circuit provided by an embodiment of the present invention;
fig. 3 is a schematic diagram of another power protection circuit according to an embodiment of the present invention;
fig. 4 is a circuit schematic diagram of another power protection circuit according to an embodiment of the present invention.
Detailed Description
In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description.
The embodiment of the utility model provides a power protection circuit. Fig. 1 shows a schematic diagram of a power protection circuit according to an embodiment of the present invention.
Referring to fig. 1, the utility model provides a power protection circuit, the protection circuit includes a primary protection circuit 10 and a secondary protection circuit 11, the input end of the primary protection circuit 10 is connected with the output end of the power, the input end of the secondary protection circuit 11 is connected with the output end of the primary protection circuit 10;
the primary protection circuit 10 comprises a voltage dependent resistor 101 and a thermistor 102, wherein the thermistor 102 is connected in series with the positive pole of the power supply, and the voltage dependent resistor 101 is connected in series between the positive pole and the negative pole of the power supply;
the secondary protection circuit 11 includes a surge suppressor 111, a MOS transistor 112 and an input resistor 113, the drain of the MOS transistor 112 is connected to the positive electrode of the power supply, the source of the MOS transistor 112 is connected to the negative electrode of the power supply, the gate of the MOS transistor 112 is connected to the charging terminal of the surge suppressor 111, the input terminal of the surge suppressor 111 is connected to the positive electrode of the power supply, the output terminal of the surge suppressor 111 is connected to the negative electrode of the power supply, and the input resistor 113 is connected between the positive electrode and the input terminal of the surge suppressor 111.
Particularly, as shown in fig. 1, the present invention provides a power protection circuit connected to a dc power supply. It will be appreciated that the dc power supply may be obtained by rectifying ac power, the positive and negative poles of which are shown as VCC and GND, respectively. The protection circuit comprises a primary protection circuit 10 and a secondary protection circuit 11, wherein the input end of the primary protection circuit 10 is connected with the output end of a power supply, and primary protection is realized through a piezoresistor 101 and a thermistor 102 in the primary protection circuit 10. The piezoresistor 101 is connected in series between the anode and the cathode of the power supply, under the condition of normal operation, the piezoresistor 101 can be regarded as a resistor with an infinite resistance value, when surge voltage exceeds the threshold value of the piezoresistor 101, the resistance value of the piezoresistor 101 becomes very small and can be ignored, the anode and the cathode of the power supply can be directly conducted, and as the power supply has grounding protection, a surge energy discharge channel can be provided, so that the surge voltage is discharged to the ground. The thermistor 102 is connected in series to the positive electrode of the power supply and used for protecting the instantaneous surge current during starting, specifically, an NTC (Negative Temperature Coefficient) thermistor can be adopted, the resistance value of the NTC thermistor at normal Temperature is large, when the surge occurs, the generated large current cannot act on subsequent circuits, along with the rise of the Temperature of the NTC thermistor and the stable operation of the circuits, the rise of the Temperature of the NTC thermistor is excited by the surge, the resistance value of the NTC thermistor is quickly reduced to a small resistance value, the voltage drop at the two ends of the NTC thermistor can be ignored, the voltage range of the rear stage is not influenced, time delay does not exist basically, and the normal operation of the rear stage circuit is not influenced. In order to improve the protection performance of lightning surge, the output end of the primary protection circuit 10 is also connected with a secondary protection circuit 11, the secondary protection circuit 11 comprises a surge suppressor 111 and an MOS (metal oxide semiconductor) tube 112, the surge suppressor 111 is also called as a surge protector and a lightning arrester, and is an electronic device for providing safety protection for various electronic equipment, instruments and meters and communication lines. The surge suppressor 111 may specifically be a control device that controls the MOS transistor 112 to be turned on or off according to the voltage from the primary protection circuit 10. The MOS transistor 112 may be an N-type MOS transistor, a drain of the MOS transistor 112 is connected to a positive electrode of the power supply, a source of the MOS transistor 112 is connected to a negative electrode of the power supply, a gate of the MOS transistor 112 is connected to a charging terminal of the surge suppressor 111, and an output terminal of the surge suppressor 111 is connected to the negative electrode of the power supply. When the voltage between the source and the gate is zero, even if a voltage is applied between the drain and the source, a PN junction in the N-type MOS transistor 112 is always in a reverse bias state, and there is no conductive channel between the drain and the source, so that the current through the drain is zero at this time. If a forward voltage is applied between the source and the gate, an N-type conduction channel from the drain to the source is gradually formed in the N-type MOS transistor 112 as the forward voltage increases, and when the forward voltage is greater than the turn-on voltage of the MOS transistor 112, the N-type conduction channel forms a drain current. The gate of the MOS transistor 112 is connected to the charging terminal of the surge suppressor 111, the input terminal of the surge suppressor 111 is connected to the positive terminal of the power supply, the output terminal of the surge suppressor 111 is connected to the negative terminal of the power supply, and the surge suppressor 111 can receive the electrical signal processed by the primary protection circuit through the positive terminal of the power supply, receive a weak starting current source, enable the surge suppressor 111 to enter a working state, and charge the source and the gate of the MOS transistor 112 through the charging terminal. The input resistor 113 is connected between the positive pole of the power supply and the input terminal of the surge suppressor 111, and can act to pull up the voltage, providing sufficient headroom. Therefore, the strength of the electric field is changed by controlling the voltage between the source electrode and the grid electrode, the purpose of controlling the magnitude of the drain current can be achieved, and the controllability of the anti-surge protection is realized.
An embodiment of the utility model provides a pair of power protection circuit has established the one-level protection circuit including piezo-resistor and thermistor, and including surge suppressor, MOS pipe and input resistance second grade protection circuit, second grade protection circuit's input is connected with one-level protection circuit's output. The voltage dependent resistor is used for providing a discharge channel for surge energy, surge voltage can be discharged to the ground, the passing of surge current is limited by the thermistor, the resistance value of the thermistor can be reduced in a short time along with the rise of temperature, the normal work of a circuit is guaranteed, and the time delay influence of protection surge is small. And the surge suppressor, the MOS tube and the input resistor in the secondary protection circuit are used in a combined mode, and the output of the MOS tube is adjusted through the surge suppressor, so that passive suppression of a traditional device is avoided, and controllability of surge voltage is guaranteed.
Optionally, referring to fig. 2, the protection circuit 10 further includes a common mode inductor 12;
the common mode inductor 12 is connected between the primary protection circuit 10 and the secondary protection circuit 11;
the common mode inductor 12 includes two windings, wherein two ends of a first winding of the common mode inductor are connected in series to a positive electrode, and two ends of a second winding of the common mode inductor 12 are connected in series to a negative electrode.
Specifically, as shown in fig. 2, the protection circuit 10 further includes a common mode inductor 12, the common mode inductor 12 is connected between the primary protection circuit 10 and the secondary protection circuit 11, the common mode inductor 12 has two coils and a ferrite bead, the two coils are respectively wound on the ferrite bead and are called a first winding and a second winding, two ends of the first winding are connected in series to a positive electrode, and two ends of the second winding are connected in series to a negative electrode. When the two windings of the common mode inductor 12 are electrified, the currents flowing through the two windings generate magnetic fields in the magnetic ring, and the magnetic fluxes of the magnetic fields are mutually superposed, so that the common mode inductor has a relatively large inductance value and plays a role in inhibiting the common mode current. When the two windings pass through the differential mode current, the magnetic lines of force in the ferrite magnetic ring are opposite, so that the magnetic fluxes are mutually cancelled, almost no inductance exists, and the differential mode signal can pass through basically without attenuation. Therefore, the common mode inductor is added behind the primary protection circuit 10, and the phenomena that the follow-up circuit is influenced by the common mode signal and is triggered by mistake can be prevented.
Optionally, referring to fig. 3, the protection circuit 10 further includes a safety capacitor 13;
the safety capacitor 13 is connected between the common mode inductor 12 and the secondary protection circuit 11; and two pins of the safety capacitor 13 are respectively connected with the cathode and the anode.
Specifically, as shown in fig. 3, the protection circuit 10 further includes a safety capacitor 13, the safety capacitor 13 is connected between the common mode inductor 12 and the secondary protection circuit 11, and pins of the safety capacitor 13 are respectively connected to a negative electrode and a positive electrode, so that a filter can be formed with the common mode inductor 12 to improve the rejection effect of the common mode signal.
Optionally, referring to fig. 3, the safety capacitor 13 includes a first safety capacitor 131 and a second safety capacitor 132;
the first safety capacitor 131 and the second safety capacitor 132 are connected in series.
Specifically, as shown in fig. 3, the safety capacitor 13 may include two Y capacitors, namely a first safety capacitor 131 and a second safety capacitor 132, which are connected in series between a high-voltage ground (i.e., an anode and a protection ground) and a low-voltage ground (i.e., a cathode and a protection ground), and the use of the two Y capacitors in series may improve a withstand voltage between the high-voltage ground and the low-voltage ground, ensure that no leakage is broken down, and prevent an event that may damage personal safety. The protective ground wire can be a metal shell of electrical equipment where a circuit is located in specific application, and the metal shell is grounded.
Optionally, referring to fig. 4, the primary protection circuit 10 further includes a starting capacitor C1, and the starting capacitor C1 is connected in parallel with the voltage dependent resistor 101.
Specifically, as shown in fig. 4, a starting capacitor C1 is connected in parallel to the voltage dependent resistor 101, and a starting capacitor C1 is used as an energy storage device, so that the current and voltage transmitted to the common mode inductor 12 can be stabilized by using the charging and discharging performance of the capacitor.
Optionally, referring to fig. 4, the secondary protection circuit 11 further includes two filter capacitors, and the two filter capacitors are connected in parallel with the safety capacitor 13.
Specifically, as shown in fig. 4, in a case where the circuit noise interference is serious, two filter capacitors C2 and C3 may be connected in series between the positive electrode and the negative electrode of the common mode inductor 12 and the safety capacitor 13, and the filter capacitors C2 and C3 may be connected in parallel with the safety capacitor 13, and may form an LC circuit with the common mode inductor 12 at the previous stage to perform current limiting and smoothing filtering on the electrical signal.
Optionally, referring to fig. 4, the surge suppressor 111 is an LTC 4366.
Specifically, referring to fig. 4, when the surge voltage exceeds the threshold of the voltage dependent resistor 101, the resistance of the voltage dependent resistor 101 becomes very small and can be ignored, the positive electrode and the negative electrode of the power supply can be directly conducted, and the power supply itself has a ground protection function, so that a surge energy discharge channel can be provided, and the surge voltage can be discharged to the ground.
Meanwhile, other optional components in the circuit, such as the capacitor C1 connected in parallel with the voltage dependent resistor 101, are used as energy storage devices, and the current and voltage transmitted to the common mode inductor 12 tend to be stable by utilizing the self charge and discharge performance, so that a soft start circuit is formed.
Two capacitors C2 and C3 connected between the common mode inductor 12 and the safety capacitor 13 and the common mode inductor 12 may form an LC circuit to limit and smooth the current of the electrical signal. The filtered electrical signal further promotes the suppression effect of the common mode signal through the safety capacitor 13, and then acts on the MOS transistor 112 and the surge suppressor 111 which are connected subsequently.
As shown in fig. 4, when the surge suppressor 111 is an LTC4366, the LTC4366 may specifically adopt an LTC4366ITS8-2# TRMPBF, where the LTC4366ITS8-2# TRMPBF has 8 pins, and a VDD pin of the 8 pins is used as an input terminal of the surge suppressor 111 and connected to a positive electrode of a power supply, so as to start an input of a current source, receive a weak start current source, and enable the surge suppressor 111 to enter an operating state. The GATE pin is used as a charging end of the surge suppressor 111 and connected with the GATE of the N-type MOS transistor 112, and is used for driving the GATE of the external N-type MOS transistor 112; a switching rate control resistor R1 connected between the GATE pin and the GATE is used to control the switching rate of the MOS transistor 112.
A charge absorbing capacitor C4 connected between the GATE pin and the negative electrode is used to absorb charge from the GATE-to-drain capacitance of the MOS transistor 112 during an over-voltage transient, while also acting as a compensation element. The OUT pin is used as the output end of the surge suppressor 111, is connected with the source electrode of the N-type MOS tube 112 and the negative electrode of the power supply through a capacitor C5; the charge pump in surge suppressor 111 will turn on and draw power from the OUT pin when the OUT pin voltage is above 4.75V, which is used as a power supply and reference input for the over-voltage regulated amplifier when the OUT voltage exceeds 2.55V. The OUT pin is clamped at 5.7V and requires a capacitor of 0.22 μ F or more to bypass to the VSS pin. Specifically, the VSS pin is connected to the negative electrode as a device return line and a substrate, and the capacitor C5 on the TIMER pin TIMER and OUT pin should be connected back to the VSS pin. A resistor R2 connected between the OUT pin and the FB pin and a resistor R3 connected between the FB pin and the negative electrode can be used to control the clamping of the output voltage of the MOS transistor 112. The FB pin serves as a feedback input of the over-voltage regulating amplifier, and the voltage of the FB pin can be controlled according to the resistor R2 and the resistor R3. A capacitor C5 connected between the OUT pin and the VSS pin serves as a bypass capacitor for improving the stability of the circuit. A capacitor C6 connected to the TIMER pin is used to set the TIMER. A resistor R4 connected between the TIMER pin and the negative pole may be used in conjunction with the capacitor C5 to improve circuit stability.
Therefore, specifically, by applying LTC4366ITS8-2# TRMPBF as the surge suppressor 111, surge current can be controlled by voltage by the cooperation of the respective pins, and impact damage of surge voltage to a circuit can be avoided.
Optionally, the MOS transistor 112 is an N-type MOS transistor.
Particularly, as the switching device, in the utility model discloses an in the scheme, MOS pipe 112 can choose for use N type MOS pipe, can be through the voltage of control source and grid, the break-make of control source and drain electrode. It can be understood that, similar to the N-type MOS transistor, the P-type MOS transistor can also be used as a switching device, and the corresponding circuit needs to be adaptively changed based on different working conditions from the N-type MOS transistor.
Optionally, the common mode inductor 12 is 74821110, 744830007215 or 744831016164.
Specifically, the common mode inductor 12 may be any one of 74821110, 744830007215, and 744831016164. When 74821110 is selected, the inductance is 10mH, the maximum direct current resistance is 350m omega, the working temperature range is-40 ℃ to +125 ℃, and the maximum direct current is 700 mA. When 744830007215 is selected, its inductance is 700 muH, maximum DC resistance is 3.8m omega, working temperature range is-40 deg.C- +125 deg.C, and maximum DC current is 21.5A. When 744831016164 is selected, the inductance is 1.6mH, the maximum direct current resistance is 8.5m omega, the working temperature range is-40 ℃ to +125 ℃, and the maximum direct current is 16.4A. In practical application, the product model corresponding to the corresponding parameter can be selected according to the input and output requirements in the circuit, so that the requirements of input and output ranges are met.
The embodiment of the utility model also provides a power conversion module, which comprises a conversion chip and the protection circuit;
the input end of the primary protection circuit 10 is provided with a power interface, and the power interface is used for being connected with a power supply;
and the output end of the secondary protection circuit 11 is connected with the conversion chip.
Specifically, according to the power protection circuit capable of preventing surge disclosed in the foregoing, the above circuit may be used in a power conversion module, a power interface is disposed at an input end of the primary protection circuit 10, the power interface is used for being connected with an external power supply to implement electric energy transmission, an output end of the secondary protection circuit 11 is connected with a rear-stage circuit, and specifically, the rear-stage circuit may be an integrated circuit such as a conversion chip. The conversion chip can convert the low voltage of the power supply into the rated voltage required by the electrical appliance. The protection circuit plays a role in anti-surge protection between the conversion chip and the power supply, and the safety of the electric appliance can be ensured.
The embodiment of the utility model provides a pair of protection circuit of power has established the one-level protection circuit including piezo-resistor and thermistor, and the second grade protection circuit including surge suppressor, MOS pipe and input resistance, second grade protection circuit's input is connected with one-level protection circuit's output. The voltage dependent resistor is used for providing a discharge channel for surge energy, surge voltage can be discharged to the ground, the passing of surge current is limited by the thermistor, the resistance value of the thermistor can be reduced in a short time along with the rise of temperature, the normal work of a circuit is guaranteed, and the time delay influence of protection surge is small. And the surge suppressor, the MOS tube and the input resistor in the secondary protection circuit are used in a combined mode, and the output of the MOS tube is adjusted through the surge suppressor, so that passive suppression of a traditional device is avoided, and controllability of surge voltage is guaranteed. In addition, the application of the common-mode inductor enables the interference in a rear-stage circuit to be less, and the application of the two safety capacitors also improves the safety of surge prevention.
The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
It should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should be regarded as the protection scope of the present invention.
Finally, it should also be 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 terminal 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 terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.
The protection circuit of the power supply provided by the utility model is introduced in detail, and the principle and the implementation mode of the utility model are explained by applying a specific example, and the explanation of the above embodiment is only used for helping to understand the structure and the core idea of the utility model; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the specific implementation and application scope, to sum up, the content of the present specification should not be understood as the limitation of the present invention.
Claims (10)
1. A power supply protection circuit is characterized in that the protection circuit comprises a primary protection circuit and a secondary protection circuit, wherein the input end of the primary protection circuit is connected with the output end of a power supply, and the input end of the secondary protection circuit is connected with the output end of the primary protection circuit;
the primary protection circuit comprises a voltage dependent resistor and a thermistor, the thermistor is connected in series with the anode of the power supply, and the voltage dependent resistor is connected in series between the anode and the cathode of the power supply;
the secondary protection circuit comprises a surge suppressor, an MOS (metal oxide semiconductor) tube and an input resistor, wherein a drain electrode of the MOS tube is connected to the anode of the power supply, a source electrode of the MOS tube is connected to the cathode of the power supply, a grid electrode of the MOS tube is connected to the charging end of the surge suppressor, an input end of the surge suppressor is connected to the anode of the power supply, an output end of the surge suppressor is connected to the cathode of the power supply, and the input resistor is connected to the anode and between input ends of the surge suppressor.
2. The protection circuit of claim 1, further comprising a common mode inductance;
the common mode inductor is connected between the primary protection circuit and the secondary protection circuit;
the common mode inductor comprises two windings; and two ends of the second winding of the common-mode inductor are connected in series with the negative electrode.
3. The protection circuit of claim 2, further comprising a ballast capacitor;
the safety capacitor is connected between the common mode inductor and the secondary protection circuit;
and two pins of the safety capacitor are respectively connected with the cathode and the anode.
4. The protection circuit of claim 3, wherein the safety-rated capacitance comprises a first safety-rated capacitance and a second safety-rated capacitance;
the first safety capacitor and the second safety capacitor are connected in series.
5. The protection circuit of claim 1,
the primary protection circuit further comprises a starting capacitor, and the starting capacitor is connected with the piezoresistor in parallel.
6. The protection circuit of claim 3,
the secondary protection circuit further comprises two filter capacitors, and the two filter capacitors are connected with the safety capacitor in parallel.
7. The protection circuit of claim 1,
the surge suppressor is LTC 4366.
8. The protection circuit of claim 7,
the charging end of the surge suppressor is connected with the grid electrode of the MOS tube through a switching rate control resistor; the switching rate control resistor is used for controlling the switching rate of the MOS tube; and is
And the charging end of the surge suppressor is connected with the negative electrode through a charge absorption capacitor, and the charge absorption capacitor is used for absorbing charges from the MOS transistor gate-to-drain capacitor during overvoltage transient.
9. The protection circuit according to any one of claims 1 to 8,
the MOS tube is an N-type MOS tube.
10. A power conversion module, comprising a conversion chip and the protection circuit of any one of claims 1 to 9;
the input end of the primary protection circuit is provided with a power interface which is used for being connected with a power supply;
and the output end of the secondary protection circuit is connected with the conversion chip.
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| CN201921582422.9U CN210351011U (en) | 2019-09-20 | 2019-09-20 | Power protection circuit and power conversion module |
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| CN201921582422.9U CN210351011U (en) | 2019-09-20 | 2019-09-20 | Power protection circuit and power conversion module |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112134452A (en) * | 2020-09-16 | 2020-12-25 | 北京五力泰科技有限公司 | Power wrong wiring protection circuit |
| CN114498592A (en) * | 2021-12-17 | 2022-05-13 | 郑州中科集成电路与系统应用研究院 | Surge suppressor with adjustable input range |
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2019
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112134452A (en) * | 2020-09-16 | 2020-12-25 | 北京五力泰科技有限公司 | Power wrong wiring protection circuit |
| CN114498592A (en) * | 2021-12-17 | 2022-05-13 | 郑州中科集成电路与系统应用研究院 | Surge suppressor with adjustable input range |
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Address after: 100095 Building 2, Longxin Industrial Park, Zhongguancun environmental protection technology demonstration park, Haidian District, Beijing Patentee after: Loongson Zhongke Technology Co.,Ltd. Address before: 100095 Building 2, Longxin Industrial Park, Zhongguancun environmental protection technology demonstration park, Haidian District, Beijing Patentee before: LOONGSON TECHNOLOGY Corp.,Ltd. |