A pulse power supply controller overcurrent protection control circuit

Abstract

The invention discloses an overcurrent protection control circuit of a pulse power supply controller, which belongs to the technical field of pulse power supply controllers. The overcurrent protection control circuit includes: a current sampling circuit for collecting the current value of a power circuit; a comparator port circuit for receiving the output information of the current sampling circuit, comparing the current value with a set value, and outputting a grounding state when the current value is greater than the set value; and a high-impedance state when the current value is not greater than the set value; a comparison locking circuit for receiving the output information of the comparator port circuit, and when the output information is a high-impedance state, the pulse generating circuit operates normally; and when the output information is a grounding state, the pulse generating circuit enters an overcurrent protection state latch; and a switch tube for controlling the connection state between the pulse power supply controller and the pulse load; wherein: the output terminal of the comparison locking circuit is connected to the switch tube through an isolation driving circuit. The pulse power supply controller has an overcurrent protection function.

Description

Technical Field

[0001] The invention belongs to the technical field of pulse power supply controllers, and in particular relates to an overcurrent protection control circuit of a pulse power supply controller. Background Art

[0002] The pulse power system plays a vital role in modern electronic equipment. It is mainly responsible for providing a stable and reliable power supply for pulse loads. The performance of the power system directly determines whether the pulse load can work normally and the quality of its work. Figure 1 As shown in the figure, a common topology in the field of pulse power supply is the multi-phase pulse shaping circuit. In this circuit structure, each pulse shaping circuit contains several key components: first, the main power conversion switch is responsible for converting the input power into the specific power form required by the pulse load; second, the topological inductor plays the role of energy storage in the process of power conversion by the main power conversion switch; then, the role of the freewheeling diode is to provide a freewheeling loop for the energy storage inductor at the moment when the main power conversion switch is turned off to ensure the continuity of energy; in addition, in order to enable the inductive part of the pulse load and the energy storage inductor to obtain the required pulse edge when the load is working, an auxiliary switch is also designed in the circuit to provide the necessary freewheeling loop; finally, there is a certain phase difference between the output pulse phases of multiple pulse shaping circuits, and this phase difference is usually set to 360 degrees divided by the total number of pulse shaping circuits N, where N represents the number of pulse shaping circuits in the circuit.

[0003] Although the above multi-phase pulse shaping circuit has certain advancedness in design, unfortunately, it has an obvious defect in practical application: the circuit lacks effective overcurrent protection measures. Due to the lack of overcurrent protection, when abnormal current appears in the circuit, the current cannot be cut off or limited in time, which will greatly increase the risk of damage to the load equipment. Therefore, when using this pulse power supply system, load damage events caused by overcurrent often occur, which not only affects the normal operation of the equipment, but also increases maintenance costs and potential safety risks. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an overcurrent protection control circuit for a pulse power supply controller, which judges the working state of the pulse circuit by comparing the current sampling signal with a given reference. When the circuit output current is greater than the set value, the drive pulse of the MOSFET power tube is blocked to achieve the purpose of overcurrent protection.

[0005] The technical solution adopted by the present invention is:

[0006] A pulse power controller overcurrent protection control circuit, the pulse power controller comprising a multi-phase pulse generating circuit; an overcurrent protection control circuit is arranged in each stage of the multi-phase pulse generating circuit, the overcurrent protection control circuit comprising:

[0007] A current sampling circuit is used to collect the current value of the power circuit;

[0008] A comparator port circuit receives output information from a current sampling circuit, compares the current value with a set value, and outputs a ground state when the current value is greater than the set value; and outputs a high impedance state when the current value is not greater than the set value;

[0009] The comparison locking circuit receives the output information of the comparator port circuit. When the output information is in a high-impedance state, the pulse generating circuit works normally; when the output information is in a grounding state, the pulse generating circuit enters an overcurrent protection state latch;

[0010] The switch tube is used to control the connection state between the pulse power supply controller and the pulse load; wherein:

[0011] The output terminal of the comparison locking circuit is connected to the switch tube through an isolation driving circuit.

[0012] Preferably, a total protection switch is provided at the front stage of the pulse generating circuit. When the pulse generating circuit works normally, the comparator port circuit output on the overcurrent protection control circuit is in a high-impedance state, a small circuit is taken through the subsequent diode, the total protection switch signal is high level, and the protection switch is turned on; when the overcurrent protection state of any stage is triggered, that is, when the output of any comparator port circuit is in a grounding state, a small circuit is taken through the subsequent diode, the total protection switch signal is low level, and the total protection switch is controlled to be disconnected.

[0013] Preferably, the current sampling circuit is connected via a signal amplification circuit and a comparator port circuit.

[0014] Preferably, the comparator port circuit includes a first comparator, an RC circuit at a positive end of the first comparator is connected to a current reference value Iref, and an RC circuit at a negative end of the first comparator is connected to a signal amplification circuit for current sampling.

[0015] Preferably, the comparison locking circuit includes a No. 2 comparator, the positive end of the No. 2 comparator is connected to the comparator port circuit, the No. 2 comparator and its peripheral resistors and capacitors constitute a locking circuit, the output end of the No. 2 comparator is connected to the base of the transistor through resistors No. 8 and No. 9 to control the MOS drive signal, and when any level of overcurrent protection state is triggered, the output end of the No. 2 comparator is grounded, the transistor is cut off, and the control switch tube is turned off.

[0016] Preferably, the peripheral resistors and capacitors include resistor No. 3, resistor No. 4, resistor No. 5, resistor No. 6, resistor No. 7 and capacitor No. 3; wherein: the power terminal is connected in sequence through resistor No. 6, resistor No. 7 and the output terminal of comparator No. 2; the power terminal is grounded in sequence through resistor No. 3 and resistor No. 4, the power terminal is grounded in sequence through resistor No. 3 and capacitor No. 3, and the power terminal is connected to the positive end of comparator No. 2 through resistor No. 3.

[0017] Compared with the prior art, the advantages and positive effects of this application are:

[0018] The core of the present invention is to judge the working state of the pulse circuit by real-time monitoring and comparing the current sampling signal with the preset reference value. When it is detected that the current value output by the circuit exceeds the preset safety threshold, the present invention will immediately take measures to quickly interrupt the flow of current by blocking the driving pulse of the MOSFET power tube, effectively preventing the occurrence of overcurrent, ensuring the safe operation of the circuit, and realizing the function of overcurrent protection.

[0019] In addition, the present invention also specially designs a total protection switch, and this innovative measure further improves the reliability of the entire circuit system. In this way, even in the extreme case of a short circuit failure of the MOSFET power tube in the pulse shaping circuit, the total protection switch can respond quickly and cut off the power supply to prevent the load from being damaged by overcurrent. This design not only ensures the safety of the circuit, but also reflects the significant advantages of the present invention in improving circuit reliability, making it a safe and reliable technical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of a multi-phase pulse shaping circuit;

[0022] Figure 2 is a functional block diagram of overcurrent protection in a preferred embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of a single-stage overcurrent protection circuit in a preferred embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the position of the main protection switch in the preferred embodiment of the present invention;

[0025] Figure 5It is a schematic diagram of a protection circuit of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0027] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0028] See also Figures 1 to 5 , a pulse power supply controller overcurrent protection control circuit, mainly including a current sampling circuit, a signal amplification circuit, an error signal judgment circuit, a comparison locking circuit, an isolation drive circuit and a switch tube;

[0029] In the present invention, the design of the pulse power supply controller includes a multi-phase pulse generating circuit; in each level of the multi-phase pulse generating circuit, an overcurrent protection control circuit is specially provided to ensure the safe operation of the entire system. The overcurrent protection control circuit includes:

[0030] A current sampling circuit, whose main function is to collect the current value in the power circuit in order to monitor the current status in real time;

[0031] A comparator port circuit, which is responsible for receiving the output information of the current sampling circuit and comparing the collected current value with the preset current reference value. When the current value exceeds the preset reference value, the output of the comparator port circuit will become grounded; conversely, if the current value does not exceed the preset value, the output will remain in a high-impedance state. The comparator port circuit includes a comparator No. 1 U1, whose RC circuit at the positive end is connected to the current reference value Iref, and whose RC circuit at the negative end is connected to the current sampling signal amplification circuit;

[0032] A comparison lock circuit, which is responsible for receiving the output information of the comparator port circuit. When the output information is in a high-impedance state, the pulse generation circuit can work normally; when the output information is in a ground state, the pulse generation circuit will enter an overcurrent protection state and latch to prevent excessive current from causing damage to the circuit;

[0033] The comparison locking circuit includes a No. 2 comparator U2, the positive end of which is connected to the comparator port circuit. The No. 2 comparator U2 and its peripheral resistors and capacitors constitute a locking circuit. The output end of the No. 2 comparator U2 is connected to the base of the transistor Q1 through the No. 8 resistor R8 and the No. 9 resistor R9, thereby controlling the MOS drive signal. When any level of overcurrent protection state is triggered, the output end of the No. 2 comparator U2 will become grounded, causing the transistor Q1 to be cut off, and then controlling the switch tube to be turned off to achieve overcurrent protection;

[0034] The peripheral resistors and capacitors include a No. 3 resistor R3, a No. 4 resistor R4, a No. 5 resistor R5, a No. 6 resistor R6, a No. 7 resistor R7 and a No. 3 capacitor C3. Among them, the power terminal is connected to the output terminal of the No. 2 comparator U2 in sequence through the No. 6 resistor R6, the No. 7 resistor R7; the power terminal is grounded in sequence through the No. 3 resistor R3 and the No. 4 resistor R4; the power terminal is grounded in sequence through the No. 3 resistor R3 and the No. 3 capacitor C3; the power terminal is connected to the positive end of the No. 2 comparator U2 through the No. 3 resistor R3;

[0035] A switch tube, which is used to control the connection state between the pulse power supply controller and the pulse load; wherein:

[0036] The output terminal of the comparison locking circuit is connected to the switch tube through an isolation driving circuit to ensure stable transmission of the signal.

[0037] On the basis of the above preferred embodiment, a total protection switch can also be set between the front-stage pulse generating circuits. When the pulse generating circuit works normally, the comparator port circuit output on the overcurrent protection control circuit is in a high-impedance state, and a small circuit is taken through the rear-stage diode, and the total protection switch signal is high level, and the protection switch is turned on; when any level of overcurrent protection state is triggered, that is, when any comparator port circuit outputs a grounding state, a small circuit is taken through the rear-stage diode, and the total protection switch signal is low level, and the total protection switch is controlled to be disconnected, thereby realizing protection of the entire system.

[0038] The current sampling circuit is connected via a signal amplification circuit and a comparator port circuit, thereby ensuring accurate sampling and timely feedback of the current value.

[0039] In the multi-phase pulse generation circuit of the present invention, each pulse generation circuit is provided with an overcurrent protection circuit. The overcurrent protection circuit obtains the current value of the power circuit by sampling and compares it with the set value. When the circuit output current is greater than the set value, the system will block the driving pulse of the MOSFET power tube, thereby achieving the purpose of overcurrent protection and ensuring the safety of the power circuit and the load. The schematic diagram of overcurrent protection is shown in FIG. Figure 2 The principle of single-channel overcurrent protection circuit is as follows. Figure 3 As shown, the current value of each pulse shaping circuit is collected for overcurrent protection, so as to protect the load.

[0040] In order to increase the reliability of the circuit and prevent the load from being damaged due to the short circuit failure of the MOSFET power tube of the pulse shaping circuit, a total protection switch is set at the front end of the pulse shaping circuit. When any of the subsequent circuits triggers the overcurrent protection, the protection switch is disconnected at the same time. The position of the total protection switch is as follows: Figure 4 As shown, the protection circuit schematic is as follows Figure 5 shown.

[0041] 1. Design of comparator port circuit

[0042] See attached schematic diagram Figure 3

[0043] The comparator port circuit compares the current sampling signal with a given reference. When the current sampling signal is higher than the given reference, it is determined that the pulse power supply current exceeds the set value and the output of the comparator U1 is in a grounded state. When the current sampling signal is lower than the given reference, it is determined that the pulse power supply is working normally and the output of the comparator U1 is in a high-impedance state.

[0044] 2. Design of comparison locking circuit

[0045] See attached Figure 3 When the output of comparator U1 is in high impedance state, the level of the positive input terminal of comparator U2 is higher than the negative input terminal, the output of comparator U2 is in high impedance state, the collector and emitter of transistor Q1 are connected, the drive signal drives the switch tube M1 normally, and the pulse generation circuit works normally. When the output of comparator U1 is in ground state, the level of the positive input terminal of comparator U2 is lower than the negative input terminal level Vref, the output of comparator U2 is in ground state, the collector and emitter of transistor Q1 are disconnected, the drive signal is cut off, the switch tube M1 has no input signal, the pulse generation circuit enters the overcurrent protection state, and the level of the positive input terminal of comparator U2 is pulled down, always lower than the negative input terminal level Vref, and the overcurrent protection state is latched.

[0046] 3. Design of the main protection switch

[0047] See attached Figure 4 , attached Figure 5The position of the total protection switch is set before all pulse generating circuits. When the front stage circuit works normally, the output of the second comparator U2 is in high impedance state, and a small circuit is taken through the rear stage diode. The total protection switch signal is high level, and the protection switch is turned on. When any level of overcurrent protection state is triggered, that is, when the output of the second comparator U2 is in ground state, a small circuit is taken through the rear stage diode, and the total protection switch signal is low level, controlling the total protection switch to disconnect, so as to protect the load.

[0048] The present invention adopts a two-stage overcurrent protection circuit. When any one of the rear-stage circuits triggers the overcurrent protection, the front-end protection switch is disconnected at the same time, effectively preventing the load from being damaged due to the short-circuit failure of the MOSFET power tube of the pulse shaping circuit. Therefore, the circuit function design, circuit structure design, and overcurrent protection mechanism of the present invention are novel and have a significant effect on improving the reliability and safety of the pulse power supply system.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A pulse power controller overcurrent protection control circuit, the pulse power controller comprising a multi-phase pulse generating circuit; characterized in that: An overcurrent protection control circuit is provided in each stage of the multi-phase pulse generating circuit, and the overcurrent protection control circuit comprises: A current sampling circuit is used to collect the current value of the power circuit; A comparator port circuit receives output information from a current sampling circuit, compares the current value with a set value, and outputs a ground state when the current value is greater than the set value; and outputs a high impedance state when the current value is not greater than the set value; The comparison locking circuit receives the output information of the comparator port circuit. When the output information is in a high-impedance state, the pulse generating circuit works normally; when the output information is in a grounding state, the pulse generating circuit enters an overcurrent protection state latch; The switch tube is used to control the connection state between the pulse power supply controller and the pulse load; wherein: The output terminal of the comparison locking circuit is connected to the switch tube through an isolation driving circuit.

2. The pulse power supply controller overcurrent protection control circuit according to claim 1, characterized in that: A total protection switch is provided at the front stage of the pulse generating circuit. When the pulse generating circuit works normally, the comparator port circuit output on the overcurrent protection control circuit is in a high impedance state, and a small circuit is taken through the rear stage diode. The total protection switch signal is high level, and the protection switch is turned on. When any level of overcurrent protection is triggered, that is, when the output of any comparator port circuit is grounded, a small circuit is taken through the subsequent diode, and the total protection switch signal is low level, controlling the total protection switch to be disconnected.

3. The pulse power supply controller overcurrent protection control circuit according to claim 1, characterized in that: The current sampling circuit is connected via a signal amplifying circuit and a comparator port circuit.

4. The pulse power supply controller overcurrent protection control circuit according to claim 3, characterized in that: The comparator port circuit includes a first comparator, an RC circuit at a positive end of the first comparator is connected to a current reference value Iref, and an RC circuit at a negative end of the first comparator is connected to a signal amplification circuit for current sampling.

5. The pulse power supply controller overcurrent protection control circuit according to claim 1, characterized in that: The comparison locking circuit includes a No. 2 comparator, the positive end of the No. 2 comparator is connected to the comparator port circuit, the No. 2 comparator and its peripheral resistors and capacitors constitute a locking circuit, the output end of the No. 2 comparator is connected to the base of the transistor through resistors No. 8 and No. 9 to control the MOS drive signal, and when any level of overcurrent protection state is triggered, the output end of the No. 2 comparator is grounded, the transistor is cut off, and the control switch tube is turned off.

6. The pulse power supply controller overcurrent protection control circuit according to claim 5, characterized in that: The peripheral resistors and capacitors include resistor No. 3, resistor No. 4, resistor No. 5, resistor No. 6, resistor No. 7 and capacitor No. 3; wherein: the power terminal is connected in sequence through resistor No. 6, resistor No. 7 and the output terminal of comparator No. 2; the power terminal is grounded in sequence through resistor No. 3 and resistor No. 4, the power terminal is grounded in sequence through resistor No. 3 and capacitor No. 3, and the power terminal is connected to the positive end of comparator No. 2 through resistor No. 3.

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